E-flows Ecological and Social Predictions Scenario Report Climate Change

Okavango River Basin Environmental
Flow Assessment Scenario Report:
Ecological and social predictions
Climate Change Scenarios
(Volume 3 of 4)
Report No: 07/2009
J.M. King, et al.
December 2009

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E-flows Ecological and Social Predictions Scenario Report Climate Change

DOCUMENT DETAILS

PROJECT
Environment protection and sustainable management of
the Okavango River Basin: Preliminary Environmental
Flows Assessment
TITLE:
Scenario Report: Ecological and social predictions -
Climate Change Scenarios
VOLUME:
Volume 3 of 4
DATE: December
2009
LEAD AUTHORS:
J.M. King, C. A. Brown.
REPORT NO.:
07/2009 (Volume 3 of 4)
PROJECT NO:
UNTS/RAF/010/GEF
FORMAT:
MSWord and PDF.
CONTRIBUTING AUTHORS:
A.R. Joubert, J. Barnes, H. Beuster, P. Wolski.

THE TEAM

Project Managers
Colin Christian
Dominic Mazvimavi
Chaminda Rajapakse
Barbara Curtis
Joseph Mbaiwa
Nkobi Moleele
Celeste Espach
Gagoitseope Mmopelwa
Geofrey Khwarae
Aune-Lea Hatutale
Belda Mosepele

Mathews Katjimune
Keta Mosepele
Angola
assisted by Penehafo
Piotr Wolski
Manual Quintino (Team
Shidute

Leader and OBSC
Andre Mostert
EFA Process
member)
Shishani Nakanwe
Management
Carlos Andrade
Cynthia Ortmann
Jackie King
Helder André de Andrade
Mark Paxton
Cate Brown
e Sousa
Kevin Roberts
Hans Beuster
Amândio Gomes
Ben van de Waal
Jon Barnes
Filomena Livramento
Dorothy Wamunyima
Alison Joubert
Paulo Emilio Mendes
assisted by
Mark Rountree
Gabriel Luis Miguel
Ndinomwaameni Nashipili

Miguel Morais

Okavango Basin
Mario João Pereira
Botswana
Steering Committee
Rute Saraiva
Casper Bonyongo (Team
Tracy Molefi-Mbui
Carmen Santos
Leader)
Laura Namene

Pete Hancock

Namibia
Lapologang Magole
Shirley Bethune (Team
Wellington Masamba
Leader)
Hilary Masundire

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E-flows Ecological and Social Predictions Scenario Report Climate Change

List of reports in report series

Report 01/2009:
Project Initiation Report
Report 02/2009:
Process Report
Report 03/2009:
Guidelines for data collection, analysis and scenario creation
Report 04/2009:
Delineation Report
Report 05/2009:
Hydrology Report: Data and models
Report 06/2009:
Scenario Report: Hydrology (2 volumes)
Report 07/2009:
Scenario Report: Ecological and social predictions (4 volumes)
Report 08/2009:
Final Report

Other deliverables:
DSS Software
Process Management Team PowerPoint Presentations

Citation

No part of this document may be reproduced in any manner
without full acknowledgement of its source

This document should be cited as:

King, J.M. and Brown, C.A. 2009. Scenario Report (ecological and socialclimate change)
Volume 3 of 4. Report 07-2009 EPSMO/BIOKAVANGO Okavango Basin
Environmental Flows Assessment Project, OKACOM, Maun, Botswana. 114 pp.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Acknowledgements
Many thanks for logistical support to:
· Corinne Spadaro of FAO)
· Ros Townsend, Karl Reinecke and Rembu Magoba of Southern Waters

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Executive Summary
The Okavango River Basin Commission, OKACOM, initiated a project titled the
Environmental Protection and Sustainable Management of the Okavango River Basin
(EPSMO). This was approved by the United Nations Development Program (UNDP), to be
executed by the United Nations Food and Agriculture Organization (FAO). The standard
UNDP process is a Transboundary Diagnostic Analysis followed by a Strategic Action
Programme of joint management to address threats to the basin's linked land and water
systems. Because of the pristine nature of the Okavango River, this approach was modified
to include an Environmental Flow Assessment (EFA). To complete the EFA, EPSMO
collaborated with the BIOKAVANGO Project at the Harry Oppenheimer Okavango Research
Centre of the University of Botswana, in 2008 to conduct a basin-wide EFA for the Okavango
River system.

This is report number 7 (volume 3) in the report series for the EFA. It summarises the
predicted biophysical and socioeconomic impacts linked to climate change, with the details of
the DSS outputs provided in volume 4 of this report.

The Low and Medium water-use scenarios were re-assessed under two different climate-
change conditions: the wettest and the driest. In the previous assessments (see Volume 1),
the low scenario presented few risks for the basin but there was some risk that the medium
scenario would result in severe degradation at some points in the basin. Importantly, the
impacts associated with both the low and medium scenarios were predominately in-country.
With climate change added as an overlay, there are two possible future paths:
· The drier climate change predictions, which would reduce the localized impacts and
would increase the impacts in the lower catchment, i.e., the Delta and Boteti.
· The wetter climate change predictions, which would ameliorate the flow-related impacts
of development throughout the Delta.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Table of Contents

1.
INTRODUCTION .............................................................................................. 13
1.1.
Project background ........................................................................................... 13
1.2.
Objectives of the EF assessment ..................................................................... 13
1.3.
Recap of process and EFA report series .......................................................... 14
1.3.1
Report 01/2009: Project Initiation Report ......................................................... 14
1.3.2
Report 02/2009: Process Report ..................................................................... 14
1.3.3
Report 03/2009: Guidelines for data collection, analysis and scenario creation
.......................................................................................................................... 14
1.3.4
Report 04/2009: Delineation Report ................................................................ 14
1.3.5
Report 05/2009: Hydrology Report: Data and models ..................................... 15
1.3.6
Report 06/2009: Scenario Report: Hydrology .................................................. 15
1.3.7
Report 07/2009: Scenario Report: Ecological and social predictions .............. 15
1.3.8
Report 08/2009: Final Report ........................................................................... 15
1.4.
The scenarios ................................................................................................... 15
1.5.
Limitations ......................................................................................................... 15
1.6.
Presentation of the results ................................................................................ 16
1.6.1
Rivers and delta ................................................................................................ 16
1.6.2
Societal wellbeing ............................................................................................. 16
1.7.
Layout of the report ........................................................................................... 17
2.
The EF sites/reaches and IUAs ........................................................................ 18
2.1.
The location of the ecological sites and links with IUAs ................................... 18
3.
Indicators .......................................................................................................... 21
3.1.1
The nature and purpose of indicators ............................................................... 21
3.1.2
Biophysical indicators ....................................................................................... 21
3.1.3
Social indicators ................................................................................................ 22
4.
Water-use Scenarios ........................................................................................ 24
4.1.
Hydrological data generated for the scenarios ................................................. 26
4.2.
Incorporation of climate change predictions into the low and medium scenarios
27
4.3.
The ecologically-relevant summary statistics for the river sites under climate
change (Sites 1-6) .............................................................................................................. 27
4.4.
Summary statistics for Site 7: Xaxanaka .......................................................... 30
4.5.
Summary statistics for Site 8: Boteti ................................................................. 31
4.6.
Process follow after the generation of ecological summary data ...................... 34
5.
Biophysical results: Disciplines ......................................................................... 36
5.1.
Introduction ....................................................................................................... 36
5.2.
Geomorphology ................................................................................................ 36
5.2.1
Indicator 1: Extent - exposed rocky habitat ....................................................... 36
5.2.2
Indicator 2: Extent coarse sediments ............................................................. 37
5.2.3
Indicator 3: Cross sectional area of channel ..................................................... 37
5.2.4
Indicator 4: Extent: backwaters ......................................................................... 38
5.2.5
Indicator 5: Extent: vegetated islands ............................................................... 39

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5.2.6
Indicator 6: Sandbars at lowflow ....................................................................... 39
5.2.7
Indicator 7: Percentage clays and silts on floodplain ........................................ 40
5.2.8
Indicator 8: Extent: inundated floodplain ........................................................... 41
5.2.9
Indicator 9: Extent: pools and pans .................................................................. 42
5.2.10 Indicator 9: Extent: cut banks ........................................................................... 43
5.2.11 Indicator 10: Carbon storage ............................................................................ 43
5.2.12 Summary of geomorphological response to scenarios ..................................... 44
5.3.
Water Quality .................................................................................................... 44
5.3.1
Indicator 1: pH .................................................................................................. 44
5.3.2
Indicator 2: Conductivity ................................................................................... 45
5.3.3
Indicator 3: Temperature .................................................................................. 46
5.3.4
Indicator 4: Turbidity ......................................................................................... 46
5.3.5
Indicator 5: Dissolved oxygen ........................................................................... 47
5.3.6
Indicators 6, 7 and 8: Total nitrogen, total phosphorus and chlorophyll a ........ 48
5.3.7
Summary of water-quality responses to scenarios ........................................... 48
5.4.
Vegetation ......................................................................................................... 48
5.4.1
Indicator 1: Channel macrophytes (submerged) ............................................... 48
5.4.2
Indicator 2: Lower wet bank .............................................................................. 49
5.4.3
Indicator 3: Upper wetbank 1 (reeds) ............................................................... 50
5.4.4
Indicator 4: Upper wetbank 2 (trees/shrubs) ..................................................... 51
5.4.5
Indicator 5: River dry bank ................................................................................ 52
5.4.6
Indicator 6: Floodplain dry bank ........................................................................ 52
5.4.7
Indicator 7: River floodplain residual pools ....................................................... 53
5.4.8
Indicator 8: River lower floodplain ..................................................................... 54
5.4.9
Indicator 9: River middle floodplain ................................................................... 54
5.4.10 Indicator 10: River upper floodplain (islands) ................................................... 55
5.4.11 Delta (Site 7) Indicators .................................................................................... 56
5.4.12 Boteti (Site 8) Indicators ................................................................................... 59
5.4.13 Summary of vegetation responses to scenarios ............................................... 59
5.5.
Aquatic macroinvertebrates .............................................................................. 59
5.5.1
Indicator 1: Invertebrates in channel submerged vegetation ............................ 59
5.5.2
Indicator 2: Invertebrates in channel marginal vegetation ................................ 60
5.5.3
Indicator 3: Invertebrates in channel fine sediments ........................................ 60
5.5.4
Indicator 4: Invertebrates of channel cobbles and boulders ............................. 61
5.5.5
Indicator 5: Invertebrates of fast-flowing channels ........................................... 62
5.5.6
Indicator 6: Invertebrates in channel bedrock pools ......................................... 63
5.5.7
Indicator 7: Invertebrates of floodplain marginal vegetation ............................. 64
5.5.8
Indicator 8: Invertebrates of seasonal floodplain pools and backwaters .......... 64
5.5.9
Indicator 9: Invertebrates of mopane woodland pools ...................................... 65
5.5.10 Summary of aquatic invertebrate responses to scenarios ................................ 66
5.6.
Fish ................................................................................................................... 66
5.6.1
Indicator 1: Fish resident in river ....................................................................... 66
5.6.2
Indicator 2: Migratory floodplain dependent fish: small species ....................... 67
5.6.3
Indicator 3: Migratory floodplain dependent fish: large species ........................ 68
5.6.4
Indicator 4: Sandbank dwelling fish .................................................................. 69
5.6.5
Indicator 5: Rock dwelling fish .......................................................................... 70

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.6.6
Indicator 6: Marginal vegetation fish ................................................................. 71
5.6.7
Indicator 7: Backwater dwelling fish .................................................................. 71
5.6.8
Summary of fish responses to scenarios .......................................................... 72
5.7.
Wildlife .............................................................................................................. 72
5.7.1
Indicator 1: Semi aquatic animals ..................................................................... 72
5.7.2
Indicator 2: Frogs, snakes and small mammals ............................................... 73
5.7.3
Indicator 3: Lower floodplain grazers ................................................................ 74
5.7.4
Indicator 4: Middle floodplain grazers ............................................................... 75
5.7.5
Indicator 5: Outer floodplain grazers ................................................................. 76
5.7.6
Summary of wildlife responses to scenarios ..................................................... 76
5.8.
Birds .................................................................................................................. 77
5.8.1
Indicator 1: Piscivores of open water. ............................................................... 77
5.8.2
Indicator 2: Piscivores of shallow waters .......................................................... 77
5.8.3
Indicator 3: Piscivores and invertebrate feeders ............................................... 78
5.8.4
Indicator 4: Specialists of floodplains ................................................................ 79
5.8.5
Indicator 5: Specialists of water-lily habitats ..................................................... 80
5.8.6
Indicator 6: Specialists inhabitants of riparian fruit trees .................................. 81
5.8.7
Indicator 7: Breeders in reedbeds and floodplains ........................................... 82
5.8.8
Indicator 8: Breeders in overhanging trees ....................................................... 83
5.8.9
Indicator 9: Breeders in banks .......................................................................... 84
5.8.10 Indicator 10: Breeders on rocks and sandbars ................................................. 85
5.8.11 Summary of bird responses to scenarios ......................................................... 86
6.
Biophysical results: Integrity ............................................................................. 87
6.1.
Integrity ratings and classification of overall impact .......................................... 87
6.2.
Present-day ecological integrity for the study sites ........................................... 88
6.3.
Interpretation of integrity plots .......................................................................... 90
6.4.
Effects on the integrity of each discipline .......................................................... 90
6.4.1
Geomorphology ................................................................................................ 90
6.4.2
Water Quality .................................................................................................... 91
6.4.3
Vegetation ......................................................................................................... 93
6.4.4
Aquatic macroinvertebrates .............................................................................. 94
6.4.5
Fish ................................................................................................................... 95
6.4.6
Wildlife .............................................................................................................. 97
6.4.7
Birds .................................................................................................................. 98
6.5.
Effects on the integrity of the whole ecosystem .............................................. 100
7.
Social results .................................................................................................. 103
8.
Conclusions .................................................................................................... 104
9.
References ..................................................................................................... 105

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E-flows Ecological and Social Predictions Scenario Report Climate Change

List of Figures

Figure 2.1 Map showing site locations and linked IUAs ........................................................ 18
Figure 2.2 Sketch map of the main channels in the Okavango Basin and the location of
the study sites. Channels not represented in the study are shown in black,
and those represented are in blue. ...................................................................... 20
Figure 4.1 Annual runoff data for Site 4: Kapako (1959-2001). ............................................ 26
Figure 4.2 Percentage of the 200-km study reach of the Boteti River that will be
inundated (wet); isolated pools (pool) and dry under the present-day
simulated conditions given climatic conditions that prevailed from 1973-2002.... 31
Figure 4.3 Percentage of the 200-km study reach of the Boteti River that will be
inundated (wet); isolated pools (pool) and dry under the low scenario given
climatic conditions that prevailed from 1973-2002. .............................................. 32
Figure 4.4 Percentage of the 200-km study reach of the Boteti River that will be
inundated (wet); isolated pools (pool) and dry under the low scenario with the
driest Climatic Change (CCD) imposed on 1973-2002. ....................................... 32
Figure 4.5 Percentage of the 200-km study reach of the Boteti River that will be
inundated (wet); isolated pools (pool) and dry under the low scenario with the
wettest Climatic Change (CCW) imposed on 1973-2002. ................................... 33
Figure 4.6 Percentage of the 200-km study reach of the Boteti River that will be
inundated (wet); isolated pools (pool) and dry under the medium scenario
given climatic conditions that prevailed from 1973-2002. .................................... 33
Figure 4.7 Percentage of the 200-km study reach of the Boteti River that will be
inundated (wet); isolated pools (pool) and dry under the medium scenario
with the driest Climatic Change (CCD) imposed on 1973-2002. ......................... 34
Figure 4.8 Percentage of the 200-km study reach of the Boteti River that will be
inundated (wet); isolated pools (pool) and dry under the medium scenario
with the wettest Climatic Change (CCW) imposed on 1973-2002. ...................... 34
Figure 4.9 Summary of process within the DSS ................................................................... 35
Figure 5.1 Relationship between flood season volume and area of floodplain inundated
for Site 4: Kapako. ............................................................................................... 41
Figure 5.2 Proportions of the vegetation indicators in the study area over a 20-year
period under present-day conditions. .................................................................. 56
Figure 5.3 Proportions of the vegetation indicators in the study area over a 20-year
period under the low scenario. ............................................................................. 57
Figure 5.4 Proportions of the vegetation indicators in the study area over a 20-year
period under the low scenario with the driest estimate of climate change. .......... 57
Figure 5.5 Proportions of the vegetation indicators in the study area over a 20-year
period under the low scenario with the wettest estimate of climate change. ....... 57
Figure 5.6 Proportions of the vegetation indicators in the study area over a 20-year
period under the medium scenario. ..................................................................... 58
Figure 5.7 Proportions of the vegetation indicators in the study area over a 20-year
period under the medium scenario with the driest estimate of climate change. .. 58

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Figure 5.8 Proportions of the vegetation indicators in the study area over a 20-year
period under the medium scenario with the wettest estimate of climate
change. ................................................................................................................ 58
Figure 6.1 Integrity plot for geomorphology for the low and medium scenarios, with and
without climate change, at each of the study sites .............................................. 91
Figure 6.2 Integrity plot for water quality for the low and medium scenarios, with and
without climate change, at each of the study sites .............................................. 92
Figure 6.3 Integrity plot for vegetation for the low and medium scenarios, with and
without climate change, at each of the study sites .............................................. 93
Figure 6.4 Integrity plot for aquatic macroinvertebrates for the low and medium
scenarios, with and without climate change, at each of the study sites ............... 95
Figure 6.5 Integrity plot for fish for the low and medium scenarios, with and without
climate change, at each of the study sites ........................................................... 96
Figure 6.6 Integrity plot for wildlife for the low and medium scenarios, with and without
climate change, at each of the study sites ........................................................... 97
Figure 6.7 Integrity plot for birds for the low and medium scenarios, with and without
climate change, at each of the study sites ........................................................... 99
Figure 6.8 Overall ecosystem integrity for the low and medium scenarios, with and
without climate change, at each of the study sites ............................................ 100
Figure 6.9 Summary of expected changes in ecosystem integrity for the low and
medium scenarios under the two levels of climate change. Present-day
conditions are estimated as B-category. No CC = without climate change;
CCD = driest climate change predictions; CCW = wettest climate change
predictions. ........................................................................................................ 102

All photographs that are not acknowledged in the text are by J.M. King and C.A. Brown.
Photographs on the front cover are by The Team.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

List of Tables

Table 2.1 The Environmental Flow (EF) sites and their corresponding socio-economic
Integrated Unit of Analysis (IUA) ......................................................................... 19
Table 3.1 Biophysical indicators used in the EPSMO/BIOKAVANGO EF process.............. 21
Table 4.1 The hypothetical water-resource developments included in each scenario ......... 24
Table 4.2 Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 1: Capico. PD =
simulated present day flow regime. ..................................................................... 28
Table 4.3 Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 2: Mucundi. PD
= simulated present day flow regime. .................................................................. 28
Table 4.4 Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 3: Cuito
Cuanavale. PD = simulated present day flow regime. ........................................ 29
Table 4.5 Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 4: Kapako. PD =
simulated present day flow regime. ..................................................................... 29
Table 4.6 Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 5: Popa Falls
and Site 6: Panhandle. PD = simulated present day flow regime. ...................... 30
Table 4.7 Vegetation types used in the model ..................................................................... 30
Table 4.8 Mean percentage of cover for vegetation types in the area of the Delta
represented by Site 7, for simulated present-day conditions, and for the
present day, and for the low and medium scenarios with two levels of climate
change. ................................................................................................................ 31
Table 6.1. The South African River Categories (DWAF 1999) ............................................. 87
Table 6.2 Criteria and weights used for the assessment (from Kleynhans 1996)................ 88
Table 6.3 Results of the Habitat Integrity (after Kleynhans 1996) assessments done on-
site by the biophysical specialists at each of the study sites (October 2008) ...... 89

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Acronyms and abbreviations

DRIFT
Downstream Response to Imposed Flow Transformations
DSS
Decision Support System
EFA
Environmental Flow Assessment
EPSMO
Environmental Protection and Sustainable Management of the
Okavango River Basin
Ha hectare
HOORC
Harry Oppenheimer Okavango Research Centre
IFA
Integrated Flow Assessment
IUA
Integrated Units of Analysis
MAR
Mean Annual Runoff
Mcm
Millions of cubic metres
OBSC
Okavango Basic Steering Committee
OKACOM
Okavango River Basin Water Commission
PD Present
day
SADC
Southern African Development Community
SAP
Strategic Action Programme
TDA
Transboundary Diagnostic Analysis

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1. INTRODUCTION
1.1. Project
background
The origin of the project is described in Report 01/2009: Project Initiation Report. Essentially,
an OKACOM initiative titled the Environmental Protection and Sustainable Management of
the Okavango River Basin (EPSMO) project was approved by the United Nations
Development Program (UNDP), to be executed by the United Nations Food and Agriculture
Organization (FAO). In 2008 it collaborated with the Biokavango Project at the Harry
Oppenheimer Okavango Research Centre (HOORC) of the University of Botswana, to
conduct a basin-wide Environmental Flows Assessment (EFA) for the Okavango River
system. This would be a major part of a standard UNDP process: a Transboundary
Diagnostic Analysis (TDA) followed by a Strategic Action Programme (SAP) of joint
management to address threats to the basin's linked land and water systems. In the case of
the Okavango Basin, the standard approach, designed for rehabilitating degraded rivers,
would be modified because of the near-pristine nature of the river ecosystem.

The EFA began with a Planning Meeting in July 2008 and was finalised in June 2009. A
climate change assessment was added in October 2009. All of the EF assessments used
mainly existing knowledge and understanding of the river ecosystem and its users. It was
generally acknowledged that this was a first, low-confidence, trial run of an EFA for this
system, which should be followed by a more comprehensive and long-term exercise where
important missing data and knowledge could be addressed to provide higher-confidence
predictions.

1.2.
Objectives of the EF assessment
There were two main objectives.
· Complete a basin-wide EFA of the Okavango River system as a major part of the
wider Technical Diagnostic Analysis. This would be done through several subsidiary
objectives:
o Collate all existing hydrological data on the river system and set up a basin
hydrological model that could simulate flows under various possible future
development scenarios
o Reach agreement with the three riparian governments on the scenarios to be
explored
o Bring together specialists in a range of relevant disciplines from across the
basin to share knowledge and data, and reach consensus on the:
relationships between flow and a series of biophysical indicators of the
river system
relationships of the condition of the ecosystem and social indicators
o Develop a DSS that would capture these relationships and produce
predictions of ecological and social change for each scenario that would
complement the macroeconomic predictions emanating from a separate
exercise
o Incorporate the EFA findings in the TDA document.
· Promote basin-wide communication and collaboration, and build capacity in
collaborative basin-wide Integrated Water Resource Management in all disciplines in
all three countries. This was done by appointing a full biophysical and socio-
economic team from each of the three countries, with planning, coordination and
training done by a Process Management Team.

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To this was added a further aim to assess how climate change might affect the prediction
of development-driven change.
1.3.
Recap of process and EFA report series
The EFA ran over 12 months, from July 2008 to June 2009. The principal features and their
timing were:
· a Planning Meeting (July 2008)
· a Basin Delineation Workshop (September 2008)
· a basin field trip (October 2008)
· a series of hydrological team meetings (September 2008 to May 2009)
· specialist discipline studies and report writing (November 2008 to May 2009)
· development of Decision Support System (DSS) software to capture the specialists'
knowledge (November 2008 to May 2009)
· a Knowledge Capture Workshop (April 2009)
· a Scenario Workshop (May 2009)
· a climate change assessment (October 2009).

The full report series produced by the EFA is listed at the beginning of this report, with a
summary of the contents of each detailed below. Details aof the climate change assessment
are in Report 06 (Volume 2) and Report 07 (Volumes 3 and 4). The summary of the findings
on climate change are in the Final Project Report 08.

1.3.1
Report 01/2009: Project Initiation Report
Details the origin of the project, including the July 2008 Planning Meeting and the agreed
work plan.

1.3.2
Report 02/2009: Process Report
Describes the technical process followed in the EFA, including the division of the basin into
homogeneous units and choosing of representative sites, the data collection and knowledge
capture exercises, the hydrological modeling, the choice of indicators with which to describe
expected development-driven change, and the nature of the DSS.

1.3.3
Report 03/2009: Guidelines for data collection, analysis and scenario
creation
A set of guidelines for basin delineation; site selection, estimating ecological condition of the
sites, scenario selection, indicator selection, data collection, Response Curves construction
(these describe the flow-ecosystem and ecosystem-social impact relationships), and report
writing.

1.3.4 Report
04/2009:
Delineation Report
The results of the September 2008 workshop, containing the following: basin location and
characteristics; river zonation; delta zonation; socio-economic zonation; Integrated Units of
Analysis; and selected study sites/zones. Eight representative sites were chosen along the
system: three in Angola, two in Namibia and three in Botswana. Each would be linked to
specific socio-economic areas so that the predictions of river change could be interpreted as
predictions of social impact.

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1.3.5
Report 05/2009: Hydrology Report: Data and models
The initial work of the three-country hydrological team and the international basin hydrologist,
including choosing and setting up the hydrological and hydraulic models, field data collection,
hydrological and geohydrological data and information, water-resource development
information, and data and information sharing arrangements.

1.3.6
Report 06/2009: Scenario Report: Hydrology
Volume 1 of this report details the initial part of the scenario descriptions, including the
scenarios chosen, and the hydrological outcomes for all eight sites along the system.
Volume 2 provides the same information for the climate change scenarios.

1.3.7
Report 07/2009: Scenario Report: Ecological and social predictions
There are four volumes in this report, each addressing predicted biophysical and socio-
economic change emanating from water-resource development of the basin:
·
Volume 1:
Summary of the predicted impacts of specified low,
medium and high levels of development
· Volume 2:
Details of the DSS outputs linked to Volume 1
·
Volume 3:
Summary of the predicted impacts of modelled Wettest
and Driest Climate Change conditions on the low and medium
scenarios
· Volume 4:
Details of the DSS outputs linked to Volume 3.

1.3.8
Report 08/2009: Final Report
Summary report of the project.

1.4. The
scenarios
Through a process of government consultation, three scenarios of increasing water-use were
chosen for the EFA. The details are provided in Report 06/2009: Scenario Report:
Hydrology, and in Chapter 4 of this report.

The impact of Climate Change on two of these scenarios, low and medium water use, was
also assessed in a separate exercise. This assessment is the subject of this volume.

1.5. Limitations
The project faced financial, time and knowledge constraints that influenced its outputs. The
major of these limitations were as follows:
· A limited budget, which resulted in various important parts of the process having to be
excluded, such as training exercises at key points in the process, in-depth review of the
specialist reports and production of a glossy information brochure in accessible language
for water managers and decision makers.
· Limited warning of the project beginning, which meant that all team members were over-
committed throughout the project.
· Limited time to complete the work, which meant that the project ran on available data and
general expert knowledge of the system; virtually no new data were collected, even
where uncertainty was extremely high.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Despite this, the project stimulated a very strong and constructive team spirit and an inter-
basin collaboration that appears set to continue long after it ends.

1.6.
Presentation of the results
1.6.1
Rivers and delta
For the low and medium scenarios with two possible levels of climate change, the predicted
changes in the river and delta are evaluated in three ways:
1. time-series of abundance, area or concentration of key indicators (see list in Chapter )
under the flow regime resulting from the low and medium scenarios each with two
levels of climate change (Volume 4);
2. estimated mean percentage changes from present day in the abundance, area or
concentration of key indicators (Volume 4);
3. estimated change in discipline-specific integrity, relative to present day and to the low
and medium scenarios with no climate change (This report)
4. estimated change in overall ecological integrity, relative to present day and to the low
and medium scenarios with no climate change (This report).

1.6.2 Societal
wellbeing
The impact on local communities is assessed in terms of changes in wellbeing as a result of
the changes in tangible and intangible benefits derived from the use of water and aquatic
ecosystem resources. These changes are expressed as:

· Change in household income from agriculture
· Change in household income from natural resources

These values include subsistence and cash income. They are summed to estimate overall
change income.

All values are expressed as the aggregate for all households in the affected area. The
overall value is expressed as a percentage change in overall household income, taking all
other sources of household income into account. Note that the percentage change might not
apply to individual households, since this value might be shared by more households under
an expanded population.

Intangible impacts are expressed as the percentage change in overall recreational and
spiritual wellbeing, taking other intangible sources of wellbeing into account.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

1.7.
Layout of the report
Chapter 1:
Introduction
Chapter 2:
Location and description of the EF sites
Chapter 3:
A listing and explanation of the indicators
Chapter 4:
A description of the chosen scenarios in terms of the location and
specifications of each chosen water-resource development; a summary of the
changes in the flow regime under each scenario at each site; and introduction
of the climate change scenarios
Chapter 5:
The predictions of biophysical change per climate change scenario
Chapter 6:
The predictions of overall change in ecosystem integrity, per climate change
scenario
Chapter 7:
The predictions of socio-economic change per climate change scenario
Chapter 8:
Conclusions

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E-flows Ecological and Social Predictions Scenario Report Climate Change

2.
The EF sites/reaches and IUAs
2.1.
The location of the ecological sites and links with IUAs
The number, and to some extent the position, of the eight biophysical sites was dictated by
financial, time and safety constraints, and they did not represent the entire basin. The
locations of the eight sites, chosen in an exercise described in Report 04/2009: Delineation
Report, are given in Table 2.1 and Figure 2-1. These sites are described in Volume 1 of this
report.

Each biophysical site corresponded to a wider, socio-economic Integrated Unit of Analysis
(IUA; Figure 2-1), where it was used to represent the predicted river changes that would
affect people. These IUAs are described in Volume 1 of this report.

Figure 2-1
Map showing site locations

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Table 2.1
The Environmental Flow (EF) sites and their corresponding socio-economic
Integrated Unit of Analysis (IUA)
EF
EF Site name
Coordinates Socio-economic
IUA
Site
1 Cuebe
@
Capico
15°33'05"S; 17°34'00"E
3
2 Cubango
@
Mucundi
16°13'05"S; 17°41'00"E
2
3
Cuito @ Cuito Cuanavale
15°10'11"S; 19°10'06"E
6
4 Okavango
@
Kapako
17°49'07"S; 19°11'44"E
8
5
Okavango @ Popa Falls
18°07'02"S; 21°35'03"E
9
6 Okavango
@
Panhandle 18°21'16"S; 21°50'13"E
10
7
Okavango Delta @ Xaxanaka
19°11'09"S; 23°24'48"E
11
8 Boteti
River
20°12'51"S; 24°07'37"E1
12

The location of the study sites resulted in portions of the catchment for which no predictions
were possible in this study. These are indicated in Figure 2-2.

1
3
2
5
7
4
6
8

1 Whole river is the site. Bridge crossing provided as reference.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Figure 2-2
Sketch map of the main channels in the Okavango Basin and the location of the
study sites. Channels not represented in the study are shown in black, and
those represented are in blue.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

3. Indicators
3.1.1
The nature and purpose of indicators
In this EFA two kinds of indicators are used: biophysical and socioeconomic. They represent
attributes of the ecological and social system that are thought to be either directly or indirectly
linked to the river and its flow regime. Their predicted changes as flows change provide a
composite picture of the ecological and social impacts of the chosen water-resource
developments.

3.1.2 Biophysical
indicators
Biophysical indicators are attributes of the river ecosystem that can be described in terms of
abundance (e.g. number of elephants), area (e.g. area of exposed sand banks),
concentration (e.g. nitrates, conductivity) or cover (e.g. vegetation communities.

Those chosen by the biophysical team for use in this project are listed in Table 3.1.

Table 3.1
Biophysical indicators used in the EPSMO/BIOKAVANGO EF process
Discipline Sites
Indicators
used
Extent - exposed Rocky Habitat
Extent - Coarse Sediments
Cross Sectional Area of Channel
Extent of Backwaters
Extent of Vegetated Islands
1-6
Geomorphology
Sand Bars at low flow
Percentage Clays on Floodplain
Extent of inundated floodplain
Inundated Pools and Pans
Extent of Cut Banks
7 Carbon
sequestration
pH
Conductivity
Temperature
Turbidity
Water Quality
1-8
Dissolved oxygen
Total nitrogen
Total phosphorus
Chlorophyll a
Channel macrophytes
Lower Wet Bank (hippo grass, papyrus)
Upper Wet Bank 1 (reeds)
Upper Wet Bank 2 (trees, shrubs)
River Dry Bank
1-6
Floodplain Dry Bank
Floodplain residual pools
Lower floodplain
Middle floodplain (grasses)
Vegetation
Upper floodplain (trees,)
Open waters
Permanent swamps
Lower floodplain
Upper floodplain
7
Occasionally flooded grassland
Sporobolus islands
Riparian woodland, trees
Savanna and scrub

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Discipline Sites
Indicators
used
Open water
8
Riparian woodland, trees
Channel-submerged vegetation
Channel-marginal vegetation
Channel-fine sediments
Channel-cobbles, boulders
1-8
Macroinvertebrates
Channel rapid, fast flowing
Channel-pools
Floodplain-marginal vegetation
Floodplain-pools, backwaters
Plus for 7
Mopane woodland-pools
Fish resident in river
Migrate floodplain small fish
Migrate floodplain large fish
Fish 1-8
Fish-sandbank dweller
Fish-rock dweller
Fish-marginal vegetation
Fish in backwaters
Semi Aquatics (hippos, crocodiles)
Frogs, river snakes
Wildlife 1-8
Lower floodplain grazers
Middle floodplain grazers
Outer floodplain grazers
Piscivores - open water
Piscivores - shallow water
Piscivores and invertebrate feeders
Specialists - floodplains
Specialists - water lilies
Birds 1-8
Specialists - fruit trees
Breeders - reedbeds, floodplains
Breeders - overhanging trees
Breeders - banks
Breeders - rocks, sandbars

In the EFA process (Report 02/2009: Process Report), specialists draw Response Curves
that describe the relationship between each indicator and each relevant part of the flow
regime (Section 4.3).

3.1.3 Social
indicators
The economic activities in the basin were identified and described. They were then
examined and assessed to select those that might exhibit measurable value change if the
river/wetland system would be subjected to flow change. These were then used as the
socio-economic indicators in the EFA process. Figure 3-1shows the full list of socio-
economic indicators. Most indicators are applicable to all of the eight field study sites and 12
IUAs in the basin. The exceptions apply where, for example, there is no floodplain of
significance, and thus no floodplain grazing or floodplain crop production, or where, for
example, there are no resident people.

It is important to stress that the indicators selected are limited to values that are expected to
change under differing water use scenarios. Some natural resource uses associated with the
riverine environment provide livelihood and economic value but are unlikely to change with
flow change. An example is use of riparian tree fruits, and another is irrigated commercial
agricultural production. Some 2,600 hectares are irrigated in this way in the Namibian basin,
contributing significant income and employment for local residents. But irrigated crop

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E-flows Ecological and Social Predictions Scenario Report Climate Change

production draws water regardless of flow change. New irrigation will also form part of water
use development scenarios, itself affecting water flow.

Indicator
1. Household income - fish
2. Household income - reeds
3. Household income - floodplain grass
Total income
a. Household income
change as %
4. Household income - floodplain gardens (e.g. molapo)
%PD
g
PD
n
A. SOCIAL WELL-
5. Household income and wealth - livestock
BEING FOR
l
-
bei
LOCAL
6. Household income - tourism
HOUSEHOLDS
i
c
wel
(=a+b+c)
b. Potable
7. Potable water/water quality
water/water quality
-
econom
%PD
cio
c. Wellbeing/welfare
l so
8. Wellbeing/welfare from intangibles
from intangibles %Pd

Overal
9.1 Macro effects from tourism income excluding hh
(including multipliers)
(=A+B).
9.2 Macro effects from hh income 1-6 (including
d. National income
B. ECONOMIC-
C
multipliers etc.)
(=9.1+9.2+9.3+9.4)
WELL BEING
%PD
(nationally)
9.3 Indirect use
9.4 non-use

Figure 3-1
List of socio-economic indicators used in the EFA and their links to the broader
economy

Possible indicators affecting human wellbeing are those related to health and disease, such
as malaria, bilharzia and diarrhoea, were examined. Although their incidence is linked to the
aquatic environment these were found to not be affected specifically by flow change. Other
possible indicators included natural resource uses such as water lily use (Nymphaea sp.) for
food, and use of the sedge (Cyperus papyrus) for mat making, were rejected as indicators
either because they were considered of small import or because in some sites their use was
unlikely to be affected by flow changes. Further, not all indicators have been assigned
values. Where data are unavailable some relatively minor resources have been treated only
in discussion, despite being recognised as possibly responsive to flow change.

The indicators in Figure 3-1 are divided firstly into those affecting both local household
income, or livelihoods (indicators 1 to 8) and the broader economy, and secondly those
impacting directly on the broader economy or on societal well-being (9.1 to 9.4). The figure
shows how these all contribute ultimately to overall social and economic wellbeing.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

4. Water-use
Scenarios
The hypothetical water use and water-resource developments associated with each of the
three scenarios that were originally assessed are provided Table 4.1. Climate change
predictions were only applied to two of these: low and medium. The results for the high
scenario are presented in Volumes 1 and 2.

The process for scenario selection is described in Report 02/2009: Process Report. Water-
use scenarios are not situations that will happen; rather, they are combinations of possible
future water-resource developments that can be explored in terms of their implications, as an
aid to planning and decision-making.

The outcomes of scenarios depend on what is included as a water-resource development.
Changing the location, size or any other aspects of a possible development will change the
expected future flow regime and thus the expected ecological and social implications.

Table 4.1
The hypothetical water-resource developments included in each scenario
Medium High
Site Present
Low
Low schemes plus:
High schemes plus:
Menongue: 246 000
Menogue: 257 000
Menogue: 30 000
Menogue: 70 000
people
people
people
people
Site 1
Irrigation: Missombo 1000 ha, weir diversion
Capico
Irrigation: Menongue Agriculture 10 000 ha, pump sump on river bank

Irrigation: Ebritex 17 000 ha, pump sump on river bank
HEP: Liapeca, run-of-river, low weir, turbines d/s
ALL CAPICO DEVELOPMENTS PLUS:
HEP: Cuvango Existing / not functioning. Rehabilitation in 2009. 40m
high reservoir, 1250 Mm3, Qmax = 3.5 m3/s
HEP: Cuchi (Kaquima (Malobas)). Run-of-river. H = 14m, Qmax = 3
m3/s
HEP: Maculungungu (on Cubango u/s Caiundo). Run-of-river. H = 22m,
Qmax = 24 m3/s
Site 2
HEP: Cutato. Run-of-
Mucundi

river. H = 30m, Qmax =
6 m3/s

HEP: Rapides do
Cuelei. Run-of-river. H =
22m, Qmax = 8 m3/s
Irrigation: Cuchi, 15 000 Irrigation: Cuchi, 150 000 ha, pump intake
ha, pump intake
Irrigation : Cuvango, 10 000 ha, pump sump on

river bank
Cuito Cuanavale: 110 Cuito Cuanavale: 115 Cuito Cuanavale: 128 Cuito Cuanavale: 160
435 people
000 people
600 people
000 people
Site 3
Cuito
Cuanavale
HEP: Cuito Cuanavale (13 km u/s confluence).

Diversion, Run-of-river. H = 7m, Qmax = 90 m3/s

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Medium High
Site Present
Low
Low schemes plus:
High schemes plus:
ALL CAPICO & MUCUNDI DEVELOPMENTS PLUS:
Irrigation: Kahenge 300 Irrigation: Kahenge 700 Irrigation: Kahenge 900 ha, pump intake on river
ha, pump intake on river ha, pump intake on river bank
Site 4
bank
bank
Kapako
Irrigation: Rundu Future 1100 ha, pump intake
on river bank

Irrigation: Cuangar

Calais 45 000 ha, pump
intake on river bank
ALL CAPICO, MUCUNDI, KAPAKO AND CUITO CUANAVALE DEVELOPMENTS PLUS:
Irrigation: Longa 10 000 ha, pump intake on river
bank
Irrigation: Calais Dirico
35 000 ha, pump intake

on river bank

Irrigation: Calais Dirico
B 60 000 ha, pump
intake on river bank
Irrigation: Mukwe 560 ha, pump intake on river bank
Irrigation: Rundu-
Mashare 521 ha, pump Irrigation: Rundu-Mashare 551 ha, pump intake on river bank
intake on river bank
Irrigation: Ndiyona 870
ha, pump intake on river Irrigation: Ndiyona 1270 ha, pump intake on river bank
bank
Rundu Urban, Tower on Rundu Urban, Tower on Rundu Urban, Tower on Rundu Urban, Tower on
Site 5&6
right bank, 2.8 Mm3/a right bank, 3.0 Mm3/a right bank, 3.4 Mm3/a right bank, 4.3 Mm3/a
Popa and
Panhandle
Irrigation: Mukwe Future Irrigation: Mukwe Future
4000 ha, pump intake 10 600 ha, pump intake
on river bank
on river bank
Eastern National Carrier Eastern National Carrier
(ENC) for water supply (ENC) for water supply
from Kavango to
from Kavango to

Namibia, Tower on right Namibia, Tower on right
bank, 17 Mm3/a
bank, 100 Mm3/a
HEP: Popa Falls. Run-
of-river, Weir at Site 2.

H = 7.5 m, Qmax = 280
m3/s, 22.5 Mm3
capacity.
HEP: Cuito M'Pupa.
Run-of-river. H = 5m,
Qmax = 100 m3/s

HEP: Cuito
Chamavera (d/s
M'Pupa). Run-of-river. H
= 6m, Qmax = 100 m3/s

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Medium High
Site Present
Low
Low schemes plus:
High schemes plus:
Site 7
ALL CAPICO, MUCUNDI, KAPAKO, CUITO CUANAVALE AND POPA/PANHANDLE
Xakanaka DEVELOPMENTS
ALL CAPICO, MUCUNDI, KAPAKO, CUITO CUANAVALE, POPA/PANHANDLE
Site 8
DEVELOPMENTS, PLUS:
Boteti
Dam at Samedupi (37

MCM/a)

Details of the water-resource development included and the modeling thereof for inclusion in
the three scenarios are provided in Report 06/2009: Scenario Report: Hydrology.

4.1.
Hydrological data generated for the scenarios
The hydrological modelling for the three scenario yielded times series of daily flows for a 43-
year hydrological period (1959 - 2001) for the river sites (Sites 1-6) and a 20-year
hydrological period (1983 - 2002) for the Delta (Site 7) and Boteti (Site 8). For each
scenario, the level of water use outlined in Table 4.1 was imposed on the full hydrological
period.

300
P resent D a y
PDSim
HighDEv
MedDev
LowDev
250
MEDIAN
) 200
M
C
M
f
(
150
unof
r
nnual
A 100
50
0
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
00
01
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
20
20
Figure 4-1
Annual runoff data for Site 4: Kapako (1959-2001).

It is important to emphasise that the base hydrological for the period used, 1959-2001, show
a declining trend in mean annual runoff (e.g., Figure 4-1). This trend was primarily driven by
climatic conditions, as was borne out by a reversal of the trend in 2004-2009. Unfortunately,
these more recent data were not available for the modelling exercise. They were, however,
made available for certain sites during the Knowledge Capture Workshop. This meant that
the biophysical specialists could calibrate their response curves using the more recent data.
For the hydrological modelling of the scenarios, however, `present-day' was represented by a
simulated record for 1959-2001.

Thus, for the river sites (Sites 1, 2, 3, 4, 5 and 6), the present-day situation is defined as a
43-year hydrological period (1959 - 2001) with 2008 levels of water use applied throughout.

For the delta (Site 7) and the Boteti River (Site 8), the present-day situation is defined as a
20-year hydrological period (1983 - 2002) with 2008 levels of water use applied throughout.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

To facilitate comparison between the scenarios, each scenario comprises the same
hydrological period as the present-day scenario, with its water use levels applied throughout.
For instance, the medium scenario at Site 4: Kapako comprises the 1959-2003 period and
assumes that all of the upstream developments envisaged in the medium scenario would be
in place for the entire time.

4.2.
Incorporation of climate change predictions into the low and medium
scenarios
Three estimates of the likely effects of climate change on flow in the Okavango River system
were done. These all predicted increased rainfall and evaporation in the upper basin. These
two processes all but cancel each other out in the upper catchment, resulting in a slight nett
increase in river flows under both the driest and wettest climate change predictions. In the
Delta, however, where the situation is dominated by evaporation, for the driest climate
change predictions, the increased evaporation is not completely offset by increased rainfall or
inflows. Thus, the net result is that the Delta is drier than present day. Under the wettest
climate change predictions, the increased evaporation is offset by increased rainfall and
flows, and the resultant condition is wetter than present day. Similarly in Boteti, the driest
climate change scenario is slightly drier than present day, and the wettest climate change
scenario is slightly wetter than present day.

Higher evaporation rates may also mean that the (largely beneficial) effects of climate
change on the floodplains in the middle reaches, Sites 4 and 5, have been overestimated.

The lowest estimate (i.e., the driest predicted future) and the highest estimate (i.e., the
wettest predicted future) were subsequently used to assess the possible impacts of climate
change on outcomes predicted for the water use scenarios, which initially has not considered
climate change. The following assessments were done:
· Low scenario no climate change (L No CC)
· Low scenario driest climate change (LCCD)
· Low scenario wettest climate change (LCCW)
· Medium scenarios no climate change (M No CC)
· Medium scenario driest climate change (MCCD)
· Medium scenario wettest climate change (MCCW).

4.3.
The ecologically-relevant summary statistics for the river sites under
climate change (Sites 1-6)
The time series of daily flows were analysed using set of hydrological rules to generate the
following ecologically-relevant summary statistics for each year of record:
1. Dry season onset in weeks
2. Dry season minimum 5-day discharge in m3s-1
3. Dry season duration in days
4. Flood season onset in weeks
5. Flood type (0-6)
6. Flood season duration in days.
Details on the division of the flow regime and the generation of ecologically-relevant
summary statistics are provided in Report 03/2009: Guidelines for data collection, analysis
and scenario creation and Report 06/2009:Scenario Report: Hydrology.

The annual statistics are stored in the DSS. The median values for present day and for the
low and medium scenarios with two levels of climate change at each site, with comments
where relevant, are provided in Table 4.2 to Table 4.6. The statistics for flood season peak

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5-day magnitude and flood season volume are presented separately in Table 4.2 to Table
4.6. These were later combined to provide Flood Type (0-6).

Table 4.2
Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 1: Capico. PD =
simulated present day flow regime.
Low Medium
Flow category
PD
Comment
No CC
CCD
CCW
No CC CCD
CCW
MAR (McM)
22
14
14
14
14
14
14
No change.
Onset slightly
Dry season onset Aug
May
June
June
May
June
June
later.
Duration not
Dry season
86 212 200
200 212 200
200 ameliorated by
duration (days)
CC.
Dry season
minimum flow
12 0.4 0.4 0.4 0.3 0.4 0.4 No
change.
(m3s-1)
Flood season
Dec Jan Jan Jan Jan Jan Jan No
change.
onset
Flood season
Offsets
38 35 38 38 35 38 38 development
peak (m3s-1)
impacts.
Flood season
456 231 242 242 231 242 242 Slight
offset.
volume (Mcm)
Flood season
Slight offset of
197 97
103 103 97 103 103
duration (days)
impacts.

Table 4.3
Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 2: Mucundi. PD =
simulated present day flow regime.
Low Medium
Flow category
PD
Comment
No CC
CCD
CCW
No CC
CCD
CCW
CCW wetter than PD
under low and medium
MAR
(McM) 166
155 166
204
140 152
188 scenario. CCD is drier
than PD under medium
scenario
Dry season onset
July
July
July
July July July July No
change.
Dry season
Duration slightly
86 124 113
95 143 136
113
duration (days)
ameliorated by CC.
Dry season
minimum flow
32
16 22
28
12 16
22 CC
mitigates
low
flows.
(m3s-1)
Flood season
Flood season slightly
Jan Jan Jan Dec Jan Jan Dec
onset
earlier under CCW.
Flood season
429
430 446
562
429 449
563 Flood peak and volume
peak (m3s-1)
higher that PD under
Flood season
3713
3558 3817
5123
3178 3466
43
CCW.
55
volume (Mcm)
CCW offsets impacts.
Flood season
Medium scenario
148
135 143
183
123 128
150
duration (days)
impacts not offset under
CCD.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Table 4.4
Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 3: Cuito Cuanavale.
PD = simulated present day flow regime.
Low Medium
Flow category
PD
Comment
No CC CCD CCW
No CC CCD
CCW
CCD and CCW wetter
MAR (McM)
119
119
130
147
119
130
147
than PD.
Dry season
July July July July July July July No
change.
onset
Dry season
CCW considerable
182 182 121 48 182 121 48
duration (days)
shorter dry season
Dry season
minimum flow
CCD and CCW wetter
80 80 93 94 80 93 94 than PD.
(m3s-1)
Flood season
Onset slightly later
Jan Jan Dec
Nov Jan Dec Nov
onset
under CC.
Flood season
163 163 173 195 163 173 195
peak (m3s-1)
CCD and CCW
Flood season
1968 1968 2617 3436 1968 2617 3436
c
onsiderably wetter
volume (Mcm)
than PD.
Flood season
162 162 205 263 162 205 263
duration (days)

Table 4.5
Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 4: Kapako. PD =
simulated present day flow regime.
Low Medium
Flow category
PD
Comment
No CC CCD CCW
No CC CCD
CCW
CCW wetter than PD
under low and
medium scenario.
MAR (McM)
164
152
167
204
140
154
190
CCD is drier than PD
under medium
scenario
Dry season
July July July July July July July No
change.
onset
Dry season
CC offsets water use
135 150 138 109 168 158 132
duration (days)
impacts.
Dry season
minimum flow
CC offsets
35 20 31 40 15 23 30 development impacts.
(m3s-1)
Flood season
Jan Jan Jan Jan Jan Jan Jan No
change.
onset
Flood season
CCD offsets water
452 446 400 497 453 394 483
peak (m3s-1)
use impacts. CCW
peak and volumes
Flood season
scenarios
3694 3535 3885 5188 3209 3523 4711
volume (Mcm)
considerably higher
than PD.
Flood season
CC offsets water use
154 147 154 186 130 144 167
duration (days)
impacts.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Table 4.6
Median values for the ecologically-relevant summary statistics for the low and
medium scenarios with two levels of climate change for Site 5: Popa Falls and
Site 6: Panhandle. PD = simulated present day flow regime.
Low Medium
Flow category
PD
Comment
No CC CCD CCW
No CC CCD
CCW
CCW wetter than PD
under low and medium
MAR (McM)
270
261
287
341
245
270
324
scenario. CCD is drier
than PD under
medium scenario.
Dry season
CC offsets water use
Aug July Aug Aug July July Aug
onset
impacts.
Dry season
CC offsets water use
115 130 110 71 145 133 92
duration (days)
impacts.
Dry season
minimum flow
CC offsets water use
114 101 113 125 93
107 122 impacts.
(m3s-1)
Flood season
Jan Jan Jan Dec Jan Jan Jan No
change.
onset
Flood season
CC offsets water use
620 618 528 649 611 519 635
peak (m3s-1)
impacts.
Flood season
CCD offsets water use
5269 4980 5587 7882 4450 5038 7236
volume (Mcm)
impacts. CCW peak
and volumes scenarios
Flood season
150 143 158 190 129 141 178
con

siderably higher
duration (days)
than PD.

4.4. Summary
statistics
for Site 7: Xaxanaka
Hydrological data per se are not particularly useful in the analysis of the Okavango Delta, as
areas of inundation vary year on year with climate. Thus, while the overall proportion of
inundated area may be similar in years with similar flow characteristics, the location of the
inundated areas varies over time. For his reason, a semi-conceptual hydraulic model (Wolski
et al. 2006), which was calibrated using observed data for the period of 1968-2002, was used
to generate inundation patterns over the south-western portion of the Okavango delta, as
represented by Site 7: Xaxanaka. The output of the model is a series of vegetation
types/habitat based on duration and frequency of inundation (Table 4.7).

Table 4.7
Vegetation types used in the model
Abbreviation Description
CH-ps
Channels in permanent swamp
L-ps
Lagoons in permanent swamp
BS-ps
Backswamp in permanent swamp
SP-sf
Seasonal pools in seasonally flooded zone
Sed-sf
Seasonal sedgeland in seasonally flooded zone
Gr-sf
Seasonal grassland in seasonally flooded zone
S-sf
Savanna- dried floodplain in seasonally flooded areas

Mean percentage over for these vegetation types for simulated present-day inflows between
1983-2002 is shown in Table 4.8.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Table 4.8
Mean percentage of cover for vegetation types in the area of the Delta
represented by Site 7, for simulated present-day conditions, and for the present
day, and for the low and medium scenarios with two levels of climate change.
CH-ps L-ps BS-ps SP-sf Sed-sf Gr-sf S-sf
Inflows
Mean percentage cover
Present-day
0.49 0.98 47.58 0.89 27.27 16.32 6.47
No
CC 0.46 0.92 44.62 0.94 27.84 18.08 7.13
Low
CCD 0.21 0.41 20.02 1.18 34.44 23.60 20.13
CCW 0.49 0.99 47.95 0.94 29.74 16.12 3.77
No
CC 0.43 0.87 41.67 0.98 26.28 21.51 8.29
Medium
CCD 0.11 0.22 10.64 1.29 31.50 31.70 24.55
CCW 0.44 0.88 42.51 1.03 29.71 20.80 4.64

Details of the model used are provided in Report 05/2009: Hydrology Report: Data and
models.

4.5. Summary
statistics
for Site 8: Boteti
The percentage of the 200-km study reach of the Boteti River that will be inundated (wet);
isolated pools (pool) and dry under the present-day, low, low with two levels of climate
change, medium and medium with two levels of climate change scenarios is provided in
Figure 4-2, Figure 4-3, Figure 4-4, Figure 4-5, Figure 4-6, Figure 4-7 and Figure 4-8,
respectively.

Details of the model used to provide these data are provided in Report 05/2009: Hydrology
Report: Data and models - Volume 1 and Volume 2.

100%
90%
h
80%
70%

r
eac
m
60%
Dry
00 k
2
50%
Pool
of
40%
Wet
age
c
ent
30%
er
P
20%
10%
0%
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
00
01
02
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
20
20
20

Figure 4-2
Percentage of the 200-km study reach of the Boteti River that will be inundated
(wet); isolated pools (pool) and dry under the present-day simulated conditions
given climatic conditions that prevailed from 1973-2002.

31

E-flows Ecological and Social Predictions Scenario Report Climate Change

100%
90%
h
80%
70%

r
eac
m
60%
0 k
Dry
50%
Pool
o
f
20
e
40%
Wet
ag
c
ent
30%
er
P
20%
10%
0%
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
00
01
02
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
20
20
20

Figure 4-3
Percentage of the 200-km study reach of the Boteti River that will be inundated
(wet); isolated pools (pool) and dry under the low scenario given climatic
conditions that prevailed from 1973-2002.

100%
90%
Dry
Pool
80%
Wet
70%
60%
50%
40%
30%
20%
10%
0%
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002

Figure 4-4
Percentage of the 200-km study reach of the Boteti River that will be inundated
(wet); isolated pools (pool) and dry under the low scenario with the driest
Climatic Change (CCD) imposed on 1973-2002.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

100%
90%
Dry
Pool
80%
Wet
70%
60%
50%
40%
30%
20%
10%
0%
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002

Figure 4-5
Percentage of the 200-km study reach of the Boteti River that will be inundated
(wet); isolated pools (pool) and dry under the low scenario with the wettest
Climatic Change (CCW) imposed on 1973-2002.

100%
90%
h
80%
70%

r
eac
k
m
60%
Dry
200
50%
Pool
40%
Wet
c
entage of
30%
er
P
20%
10%
0%
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002

Figure 4-6
Percentage of the 200-km study reach of the Boteti River that will be inundated
(wet); isolated pools (pool) and dry under the medium scenario given climatic
conditions that prevailed from 1973-2002.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

100%
90%
Dry
Pool
80%
Wet
70%
60%
50%
40%
30%
20%
10%
0% 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2
197
197
197
197
197
197
197
198
198
198
198
198
198
198
198
198
198
199
199
199
199
199
199
199
199
199
199
200
200
200

Figure 4-7
Percentage of the 200-km study reach of the Boteti River that will be inundated
(wet); isolated pools (pool) and dry under the medium scenario with the driest
Climatic Change (CCD) imposed on 1973-2002.

100%
90%
Dry
Pool
80%
Wet
70%
60%
50%
40%
30%
20%
10%
0% 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2
197
197
197
197
197
197
197
198
198
198
198
198
198
198
198
198
198
199
199
199
199
199
199
199
199
199
199
200
200
200

Figure 4-8
Percentage of the 200-km study reach of the Boteti River that will be inundated
(wet); isolated pools (pool) and dry under the medium scenario with the wettest
Climatic Change (CCW) imposed on 1973-2002.

4.6.
Process follow after the generation of ecological summary data
Once the summary ecological data are generated they are entered into the DSS. In the
DSS, the response curves are used to predict the biophysical and social outcomes for the
flow regime of interest. The DSS is described in more detail in Report 02/2009: Process
Report.

34

E-flows Ecological and Social Predictions Scenario Report Climate Change

OUTPUTS
Ecologically
relevant
1.
time-series of abundance,
flow categories
area or concentration of
key indicators;
2.
estimated mean
percentage changes from
present day in the
abundance, area or
Biophysical Discipline
concentration of key
Response Curves
indicators
3.
estimated change in
discipline-specific
integrity, relative to
present day
Social Discipline
4.
estimated change in
Response Curves
overall ecological
integrity, relative to
present day

Figure 4-9
Summary of process within the DSS

35

E-flows Ecological and Social Predictions Scenario Report Climate Change

5.
Biophysical results: Disciplines
Note:
1.
The results presented here are unique to the configuration of development options, and
their operating rules, included in the water-use scenarios. Different configurations,
and/or different operating rules would yield different outcomes for the biophysical
environment.
2.
The results presented here exclude consideration of:impacts of developments other
than flow, e.g., changes in sediment supply; landuse changes.
3.
The only water use included in the scenarios for the Cuito River upstream of Site 3:
Cuito River at Cuito Cuanavale was a run-of-river hydropower plants that had no effect
on the flows at Site 3. Thus, none of the scenarios affected Site 3.
4.
The locations of the sites prohibit the prediction of likely impacts of any of the scenarios
on the lower Cuito River.
5.
Climate change impacts are assessed primarily in relation to the low and medium
scenarios, but reference is also made to present day situations, as the predicted wetter
conditions may change the river from the present.
6.
Occasionally the range of summary flow statistics for CC was outside the range used
for the Response Curves. Where this occurred, the nearest value was used.
Extension of the Response Curves could be done, but was not possible in the CC
extension of this project. Using nearest values may have muted some predicted
responses.

5.1. Introduction
The Chapter summarises the results for each of the biophysical indicators in terms of overall
changes in their area, concentration or abundance relative to the simulated present day
situation.

Additional details on the biophysical results for each scenario presented here are provided in
Report 07/2009: Scenario Report: Ecological and social predictions (VOLUME4).

5.2. Geomorphology
5.2.1
Indicator 1: Extent - exposed rocky habitat
Summary of characteristics
This indicator considers the extent of exposed rocky habitat at a site during the low flow
season. It does not consider the other potential impacts, such as of sediment deposition
covering bedrock exposures, only the exposed bedrock above the water surface. Exposed

36

E-flows Ecological and Social Predictions Scenario Report Climate Change

rocky areas provide valuable habitat for birds and wildlife. There is a direct relationship
between flow level and rocks exposed above water level. As water level rises, less rocky
area is exposed.

This indicator is used for Sites 1, 2 and 5.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
>PD NSC NSC >PD NSC >PD+>MS
2
>PD
>PD+<LS >PD+<LS >PD
>PD+<MS >PD+<MS
3 n/a n/a n/a n/a n/a n/a
4 n/a n/a n/a n/a n/a n/a
5
PD NSC NSC PD NSC NSC
6 n/a n/a n/a n/a n/a n/a

5.2.2
Indicator 2: Extent coarse sediments
Not used in final analysis.

5.2.3
Indicator 3: Cross sectional area of channel
Summary of characteristics
The cross sectional area of the channel responds mainly to flood conditions. Floods larger
than the historical maximum should rapidly enlarge the cross sectional area, and a reduction
of floods should result in a narrowing of the flood channel (and a reduction in channel cross-
sectional area). However, the channel also responds to low flow conditions or extended low
flow conditions, which enables vegetation to encroach into the channel, trapping sediment,
ultimately reducing the channel cross section. This process is much slower than channel
enlargement, and intervening floods will offset this to a certain extent.

This indicator is used for Sites 1, 2, 3, 4, 5 and 6.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Impact of the Low and Medium Scenarios under Climate Change
`
`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2 PD
NSC
>PD+>LS
<PD
NSC
>PD+>MS
3
PD NSC NSC PD NSC NSC
4
<PD
>PD+>LS >PD+>LS <PD
NSC
>PD+>MS
5
PD NSC NSC PD NSC NSC
6
<PD NSC NSC <PD NSC NSC

5.2.4
Indicator 4: Extent: backwaters
Summary of characteristics
Backwater provide valuable habitat for plants, fish, birds and wildlife. Filling or emptying of
backwaters is directly related to the water level in the river. Backwaters gradually fill with
sediment and therefore may be shallower than the main channel - in that case they may
empty before the river dries up. The backwaters tend to be steep sided, so the surface area
changes little as water depth changes.

This indicator is used for Sites 1, 3 and 4.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2 n/a n/a n/a n/a n/a n/a
3 PD NSC
<PD+<LS
PD NSC
<PD+<LS
4
<PD <PD+>LS
PD+>LS
<PD <PD+>MS
<PD+>MS
5 n/a n/a n/a n/a n/a n/a
6 n/a n/a n/a n/a n/a n/a

38

E-flows Ecological and Social Predictions Scenario Report Climate Change

5.2.5
Indicator 5: Extent: vegetated islands
Summary of characteristics
Vegetated islands in the Mukwe-Andara-Popa Falls section of the Okavango River (and
upstream) are normally comprised of sand on bedrock. Grass, reeds, bush and trees
stabilise the sand by reducing wash away during above-average high flows and also
promoting deposition of more sand during overtopping of the island.

Reduced flows have little impact on vegetated islands as long as the plants there still get
enough water to survive and regenerate. Excessively high floods, however, are likely to
cause erosion of the margins of islands. In many cases this erosion is limited to the margins
because of the bedrock base to the island.

This indicator is used for Site 5.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a n/a n/a n/a n/a n/a
2 n/a n/a n/a n/a n/a n/a
3 n/a n/a n/a n/a n/a n/a
4 n/a n/a n/a n/a n/a n/a
5
PD NSC NSC PD NSC NSC
6 n/a n/a n/a n/a n/a n/a

5.2.6
Indicator 6: Sandbars at lowflow
Summary of characteristics
Extensive exposed sand bars exist mainly below Popa Falls. Upriver, although much of the
river bed is sand, the sand bars are mostly submerged just below the surface during the low
flow season.

If only the effect of water flow on sandbanks is considered, then lower flow will expose a
greater extent of sandbanks. However, the real issue the fact that dams and weirs trap
sediment. Downstream of a weir or dam the river is deprived of sediment, so it erodes its
bed, banks and floodplains until it is once again carrying its maximum load. Thus, for some
distance downstream of a weir or dam the sandbanks will be removed. This is important at
Sites 2 and 5 were dams/weirs form part of the high scenario, but is not included in the
results for this indicator as sediment trapping by dams was not included in the DSS. If there
were, the impacts would likely be considerably higher than predicted here.

This indicator is used for Site 5.

39

E-flows Ecological and Social Predictions Scenario Report Climate Change

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a
n/a
n/a
n/a
n/a
n/a
2 n/a
n/a
n/a
n/a
n/a
n/a
3 PD NSC

NSC
PD NSC

NSC
4 PD NSC

NSC
PD NSC

NSC
5 n/a
n/a
n/a
n/a
n/a
n/a
6 PD NSC

NSC
PD NSC

NSC

5.2.9
Indicator 9: Extent: pools and pans
Summary of characteristics
This indicator considers the extent of perennial pools and pans on the floodplains at Sites 3,
4 and 6. These are partly dependent on refilling from overbank flooding and rain, but are
sustained through the lowflow season by the high water table on the floodplains. As the river
level drops, so the water table in the floodplain will also drop. If the bed of a pool no longer
intersects the water table, the pool will dry out, although seepage from the non-saturated
zone may also contribute to pool water.

This indicator is used for Sites 3, 4 and 6.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a
n/a
n/a
n/a
n/a
n/a
2 n/a
n/a
n/a
n/a
n/a
n/a
3
PD
>PD+>LS >PD+>LS PD
>PD+>LS >PD+>LS
4
<PD
<PD+>LS >PD+>LS <PD
<PD+>MS <PD+>MS
5 n/a
n/a
n/a
n/a
n/a
n/a
6
PD NSC NSC PD NSC NSC

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.2.10
Indicator 9: Extent: cut banks
Summary of characteristics
Cut banks are a natural phenomenon in the Okavango, particularly in the middle reaches
through Namibia. Higher flow velocities during flooding erode banks, building meanders and
creating cutoffs. This process is enhanced if water levels drop rapidly, as hydrostatic
pressure of water in the sandy bank material tends to result in bank collapse. A decline in
bank cutting will result in a gradual stabilization of the channel and a loss of habitat.

This indicator is used for Sites1, 3, 4 and 6.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
PD NSC NSC PD NSC NSC
2 n/a
n/a
n/a
n/a
n/a
n/a
3
PD
>PD+>LS >PD+>LS PD
>PD+>LS >PD+>LS
4 <PD
>PD+>LS
>PD+>>LS PD NSC
>PD+>MS
5 n/a
n/a
n/a
n/a
n/a
n/a
6
PD NSC NSC PD NSC NSC

5.2.11
Indicator 10: Carbon storage
Summary of characteristics
Wetlands affect the levels of atmospheric carbon in two ways: First, many wetlands,
particularly boreal and tropical peatlands, are carbon reservoirs. Carbon is contained in the
standing crops of trees and other vegetation and in litter, peats, organic soils and sediments
that have been built up, in some instances, over thousands of years. These carbon
reservoirs may supply large amounts of carbon to the atmosphere if water levels are lowered
or land management practices result in oxidation of soils. Second, many wetlands also
continue to sequester carbon from the atmosphere through photosynthesis by wetland
plants; many also act as sediment traps for carbon-rich sediments from watershed sources.
However, wetlands also simultaneously release carbon as carbon dioxide, dissolved carbon,
and methane. The net carbon sequestering versus carbon release roles of wetlands are
complex and change over time although net, gradual sequestration occurs over time for
peatland wetlands such as the Okavango Swamp2.

This indicator considers the net peat/carbon storage in the swamps.

This indicator is used for Site 7.

2 www.usgcrp.gov/usgcrp/Library/nationalassessment/newsletter/1999.08

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
>PD NSC NSC >PD NSC NSC
2
PD
NSC NSC >PD
NSC NSC
3
PD
NSC NSC PD
NSC NSC
4
>PD NSC PD+<LS
>PD NSC NSC
5
PD
NSC NSC PD NSC PD+<MS
6
PD NSC NSC PD NSC NSC
7 PD >PD+>LS
NSC
PD >PD+>MS
NSC
8 PD
>PD+>LS
NSC
>PD
>PD+>MS
NSC

5.3.2
Indicator 2: Conductivity
Summary of characteristics
Values are those for the main channel. Generally, conductivity increases with decreasing
flow.

This indicator is used for all eight sites.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
>>PD NSC NSC >>PD NSC NSC
2
>PD >PD+<LS
PD+<LS
>PD >PD+<MS
PD+<MS
3
PD
>PD+>LS >PD+>LS PD
>PD+>MS >PD+>MS
4
>PD PD+<LS
<PD+<LS
>PD >PD+<MS
PD+<MS
5 PD
NSC
>PD+>LS
>PD
PD+<MS
PD+<MS
6
>PD NSC PD+<LS
>PD >PD+<MS
PD+<MS
7
PD
>PD+>LS >PD+>LS >PD
>PD+>MS >PD+>MS
8
>PD
>PD+>LS <PD+<LS >PD
>PD+>MS <PD+<MS

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.3.3
Indicator 3: Temperature
Summary of characteristics
Diel temperature ranges are addressed. These are expected to increase with development
that reduces river flow.

This indicator is used for all eight sites.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
>PD NSC NSC >PD NSC NSC
2 >PD
>PD+<LS
PD+<LS
>PD
>PD+<MS
>PD+<MS
3 PD
NSC
>PD+>LS
PD
NSC
>PD+>MS
4 >PD
>PD+<LS
PD+<LS
>PD
>PD+<MS
PD+<MS
5
PD NSC NSC >PD >PD+<MS
PD+<MS
6
PD
>PD+>LS >PD+>LS >PD
>PD+<MS >PD+<MS
7
PD
>PD+>LS >PD+>LS >PD
>>PD+>>MS >PD+>MS
8
>PD
>PD+>LS <PD+<LS >PD
>>PD+>>MS <PD+<MS

5.3.4
Indicator 4: Turbidity
Summary of characteristics
Turbidity decreases with decreasing flow at Sites 1 and 2. Values increase with high flows in
the flood season, as sediments are lifted into suspension.
This indicator is used for all eight sites.

Impact of the Low and Medium Scenarios under Climate Change

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2
<PD <PD+>LS
PD+>LS
<PD <PD+>MS
<PD+>MS
3
PD
<PD+<LS <PD+<LS PD
<PD+<MS <PD+<MS
4
PD NSC NSC PD <PD+<MS
<PD+<MS
5
<PD PD+>LS
>PD+>LS
<PD PD+>MS
PD+>MS
6 PD
NSC
>PD+>LS
<PD
PD+>MS
>PD+>MS
7
PD NSC NSC >PD >PD+>MS
NSC
8
<PD
<PD+<LS >PD+>LS <PD
<PD+<MS >PD+>MS

5.3.5
Indicator 5: Dissolved oxygen
Summary of characteristics
Decrease in flow results in an increase in Dissolved Oxygen at sites 1 - 6. At sites 7 and 8
the concentrations decrease with a decrease in flow.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different. <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
>PD NSC NSC >PD NSC NSC
2
>PD >PD+<LS
PD+<LS
>PD >PD+<MS
>PD+<MS
3
PD
<PD+<LS <PD+<LS PD
<PD+<MS <PD+<MS
4
>PD >PD+<LS
PD+<LS
>PD >PD+<MS
PD+<MS
5
>PD >PD+<LS
PD+<LS
>PD >PD+<MS
<PD+<MS
6
>PD >PD+<LS
PD+<LS
>PD >PD+<MS
<PD+<MS
7 PD <PD+<LS
PD <PD
<PD+<MS
NSC
8
<PD
<PD+<LS >PD+>LS <PD
<PD+<MS >PD+>MS

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.3.6
Indicators 6, 7 and 8: Total nitrogen, total phosphorus and chlorophyll a
Summary of characteristics
Concentrations increase with decreasing flow at all the sites, but the relationship is slightly
weaker for phosphorus.

This indicator is used for all eight sites.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 >PD
NSC
NSC
>PD
NSC NSC
2
>PD
>PD+<LS PD+<LS >PD
>PD+<MS >PD+<MS
3
PD
<PD+<LS PD+<LS PD
<PD+<MS PD+<MS
4
>PD
>PD+<LS PD+<LS >PD
>PD+<MS PD+<MS
5
>PD
>PD+<LS PD+<LS >PD
>PD+<MS <PD+<MS
6
>PD
>PD+<LS >PD+>LS
>PD
>PD+<MS PD+<MS
7 >PD
>>PD+>>LS >PD+>LS >PD
>>PD+>>MS >PD+>MS
8
>PD
>PD+>LS <PD+<LS
>PD
>PD+>MS <PD+<MS

5.3.7
Summary of water-quality responses to scenarios
The water quality of the Okavango system is good, and values of all indicators are predicted
to remain mostly within the natural variability through the low and medium scenarios. The
situation remains similar in the upper catchment under climate change, where water quality is
expected to be fairly natural. However, in the lower catchment, the driest climate change
predictions are expected to result in poor water quality in the Delta and Boteti.

As previously noted (Volume 1), not all chemical variables are addressed in this exercise,
and that for those included only the direct changes as a result of flow changes are described.
Water-use developments, as represented by the scenarios, will likely cause additional water-
quality changes, brought about by increased effluents from urban areas, agricultural return
flows carrying pesticides and fertilisers, and changed DO and temperature levels caused by
storage dams.

5.4. Vegetation
5.4.1
Indicator 1: Channel macrophytes (submerged)
Representative species: Potamogeton spp. (pondweed), Vallisneria aethiopica (no common
name) and Lagarosiphon ilicifolius (oxygen weed).

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Summary of characteristics
These are species that grow along the edges of main channel or in side channels. All or part
of vegetation is permanently submerged, and the plants are either rooted or floating. They
need permanent, flowing, clear water. Their cover increases or decreases depending on
water volume in lowflow season and could decline to zero if the channel dries out. Sudden or
very large floods could also reduce cover. Poor water quality or low light penetration will also
negatively affected them.

These plants are used as indicators for Sites 1, 2, 3, 4, 5 and 6.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC PD NSC NSC
2
PD NSC NSC <PD <PD+>MS
<PD+>MS
3 PD NSC
>PD+>LS
PD NSC
NSC
4
PD NSC NSC <PD <PD+>MS
<PD+>MS
5
PD NSC NSC PD NSC NSC
6 PD NSC
<PD+<LS
PD NSC
NSC

5.4.2
Indicator 2: Lower wet bank
Representative species: Vossia cuspidata, Cyperus papyrus.

Summary of characteristics
These are species that grow along the permanently wet inner margin in main channel. They
are either floating plants with stems forming dense mat, with leaves and flowers above water
or rooted in the sand/peat. They prefer flowing water to standing water.

Vossia cuspidata is a robust, perennial grass with spongy, floating, creeping stems,
associated with deep, permanent water. It is rooted in the channel bed, but the extremely
long, floating stems can trail out into the current. Cyperus papyrus is a large, perennial
sedge with stout creeping stems and erect stems in permanent swamps and on the margins
of large rivers.

Papyrus and hippo grass respond slightly differently to flow but as a general rule they do not
occur at the same site (or at least they dominate at different sites). Hippo grass will survive
as long at there is water to cover its roots, and its leaves will float higher or lower as water
level rises or falls. It can tolerate more desiccation than can papyrus.

These plants are used as indicators for Sites 4, 5 and 6.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different.
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2
PD NSC NSC PD NSC NSC
3
PD NSC NSC PD NSC NSC
4
PD NSC NSC PD NSC NSC
5
PD NSC NSC PD NSC NSC
6
PD NSC NSC PD NSC NSC

5.4.4
Indicator 4: Upper wetbank 2 (trees/shrubs)
Representative species: Searsia (Rhus) quartiniana, Ziziphus mucronata.

Summary of characteristics
Searsia (Rhus) quartiniana is a dense shrub or tree with a wide range of ecological
tolerances within the context of perennial rivers. It is found along the banks and floodplains
of perennial rivers, on islands in permanent swamps, as well as occasionally in ephemeral
watercourses. Ziziphus mucronata is found in a variety of different habitats; very often close
to water, but can also be found far from water.

These plants are used as indicators for Sites 1, 2, 4 and 5.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different.
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2
<PD PD+>LS
>PD+>LS
<PD <PD+>MS
PD+>MS
3 n/a n/a n/a n/a n/a n/a
4
<PD
PD+>LS PD+>LS <PD
<PD+>MS
PD+>MS
5
PD NSC NSC PD NSC NSC
6 n/a n/a n/a n/a n/a n/a

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.4.5
Indicator 5: River dry bank
Representative species: Combretum imberbe, Acacia tortilis, Albizia versicolor, Ficus
sycomorus, Garcinia livingstonei and Diospyros mespiliformis3.

Summary of characteristics
This group of species comprises large trees and dense shrubs that grow on the outer
margins of river banks. They are important for stabilising the river bank, and filter runoff from
the adjacent catchment. They grow near water but generally not in the water, although some
can withstand short periods of inundation. These trees and shrubs get their water via
groundwater seepage from the river.

These plants are used as indicators for Sites 1, 2, 3, 5 and 6.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2
PD NSC NSC PD NSC NSC
3
PD NSC NSC PD NSC NSC
4 n/a n/a n/a n/a n/a n/a
5
PD NSC NSC PD NSC NSC
6
PD NSC NSC PD NSC NSC

5.4.6
Indicator 6: Floodplain dry bank
Representative species: Combretum imberbe, Acacia tortilis, Albizia versicolor, Ficus
sycomorus, Garcinia livingstonei and Diospyros mespiliformis.

Summary of characteristics
This group comprises the same species are Indicator 5: River dry bank. The difference
between them lies in the fact that this groups grows on the outer margin of the floodplain,
which means that they are more dependent on periodic inundation of the floodplain than are
their riverbank counterparts.

These plants are used as indicators for Site 6.

3 Different species occur at different sites.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
No CC
Driest CC
Wettest CC No CC
Driest CC
CC
1 n/a
n/a
n/a n/a
n/a
n/a
2 n/a
n/a
n/a n/a
n/a
n/a
3 n/a
n/a
n/a n/a
n/a
n/a
4 n/a
n/a
n/a n/a
n/a
n/a
5 n/a
n/a
n/a n/a
n/a
n/a
6 PD
NSC
NSC
NSC
NSC
NSC

5.4.7
Indicator 7: River floodplain residual pools
Representative species: Nymphaea nouchali var. caerulea

Summary of characteristics
The plants of this community are all dependent on standing or slow-flowing, permanent
water, which is linked to and recharged by the main river. This is a seasonal effect as rain
will fill the pools during the rainy season and flood-waters will fill them during the flood
season.

These plants are used as indicators for Sites 3, 4 and 6.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
No CC
Driest CC
Wettest CC No CC
Driest CC
Wettest CC
1 n/a n/a n/a n/a n/a n/a
2 n/a n/a n/a n/a n/a n/a
3 PD >PD+>LS
>PD+>LS
PD >PD+>MS
>PD+>MS
4 <PD
PD+>LS
>>PD+>>LS <PD <PD+>MS
>>PD+>>MS
5 n/a n/a n/a n/a n/a n/a
6 PD NSC NSC PD NSC NSC

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.4.8
Indicator 8: River lower floodplain
Representative species: Miscanthus junceus, Persicaria spp., Ludwigia spp.

Summary of characteristics
These plants are found in the deeper depressions on the floodplains, which receive water
from the river at high flow and presumably retain water for long periods, based on the water-
loving species that are found in them. The group comprises a mixture of species that prefer
permanent water or grow on dry land but close to water (Persicaria, Ludwigia). They are all
tolerant of total inundation for long periods and desiccation for varying periods. Their leaves
float on the surface of the water, while the flowers are held above the water.

Miscanthus junceus (swamp savanna grass/pampas grass) is an important floodplain
thatching grass in Namibia (Barnes, in litt. 2009).

These plants are used as indicators for Sites 3, 4 and 6.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a n/a n/a n/a n/a n/a
2 n/a n/a n/a n/a n/a n/a
3 n/a n/a n/a n/a n/a n/a
4
>PD
<PD+>LS <PD+>LS <PD
<PD+>MS PD+>MS
5 n/a n/a n/a n/a n/a n/a
6 PD NSC
>PD+>LS
PD NSC
NSC

5.4.9
Indicator 9: River middle floodplain
Representative species: Setaria, Panicum, Vetiveria nigritana4, thatching grasses.

Summary of characteristics
Plants in this group are able to grow in areas away from water, but thrive in seasonally wet
areas. They are found predominately on the middle floodplain, on either clay or sand. There
tend to be large areas dominated by thatching and grazing grasses. An increase in the
length of inundation may be detrimental, but they would probably survive longer dry periods.

These plants are used as indicators for Sites 3, 4 and 6.

4 Angolan sites and the Panhandle.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
No CC
Driest CC
No CC
Driest CC
Wettest CC
CC
1 n/a
n/a
n/a
n/a
n/a
n/a
2 n/a
n/a
n/a
n/a
n/a
n/a
3 PD
NSC
<PD+<LS
PD
PD+<MS
<<PD+<<MS
4 >PD
PD+<LS
<PD+<<LS >PD NSC PD+<MS
5 n/a
n/a
n/a
n/a
n/a
n/a
6 PD
NSC
<PD+<LS
PD
NSC
<PD+<MS

5.4.10
Indicator 10: River upper floodplain (islands)
Representative species: Searsia (Rhus) with Acacia hebeclada, Acacia sieberiana,
Diospyros lycioides, grasses.

Summary of characteristics
These are the highest points on the floodplain itself and are seldom inundated. Long
inundation is detrimental to these plants. They are, however, dependent on some inundation
to recharge ground water, and for nutrients. The plant community is comprised of grasses,
shrubs, a few trees, and is equivalent to the wildlife discipline's secondary floodplain.

These plants are used as indicators for Sites 2 and 4.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a n/a n/a n/a n/a n/a
2
PD NSC NSC PD NSC NSC
3 n/a n/a n/a n/a n/a n/a
4
PD NSC NSC PD NSC NSC
5 n/a n/a n/a n/a n/a n/a
6 n/a n/a n/a n/a n/a n/a

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.4.11
Delta (Site 7) Indicators
The indicators used for Site 7: Okavango Delta at Xaxanaka are:
1. Open
water
2. Permanent
swamps
3. Lower
floodplain
4. Upper
floodplain
5. Occasionally-flooded
grassland
6.
Sporobolus islands (These are small islands that form on termitaria in the seasonal
grasslands).
7.
Riparian woodland, trees
8. Savanna,
scrub.

These represent a gradient of wetness from open water through to savanna. Under natural
conditions proportion of these vegetation types fluctuates with climatic variation. Essentially,
under wet conditions there will be a predominance of open water, permanent swamp and
lower floodplains. If conditions dry out, the relative extent of upper floodplain and
occasionally-flooded grasses will increase. If conditions were to dry out further, there would
be a gradual terrestrialisation of the delta and large portions thereof would revert to savanna,
with small Sporobolus islands on termitaria. If, however, conditions in the delta get wetter
then the open water, permanent swamp and floodplain vegetation would increase.

Impact of the Low and Medium Scenarios under Climate Change
The relative proportions of the vegetation indicators in the study area under present day, and
the low and medium scenarios with two levels of climate change are shown in Figure 5-2 to
Figure 5-8, respectively.

100%
80%
60%
40%
20%
0%
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
Open w ater
Permanent sw amp
Low er floodplain
Upper floodplain
Occassionally-flooded grasslands
Savanna

Figure 5-2
Proportions of the vegetation indicators in the study area over a 20-year period
under present-day conditions.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

100%
80%
60%
40%
20%
0% 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Open w ater
Permanent sw amp
Low er floodplain
Upper floodplain
Occassionally-flooded grasslands
Savanna

Figure 5-3
Proportions of the vegetation indicators in the study area over a 20-year period
under the low scenario.

100%
90%
80%
S-sf
70%
Gr-sf
60%
Sed-sf
50%
SP-sf
40%
BS-ps
30%
L-ps
20%
CH-ps
10%
0% 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Figure 5-4
Proportions of the vegetation indicators in the study area over a 20-year period
under the low scenario with the driest estimate of climate change.

100%
90%
80%
S-sf
70%
Gr-sf
60%
Sed-sf
50%
SP-sf
40%
BS-ps
30%
L-ps
20%
CH-ps
10%
0% 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Figure 5-5
Proportions of the vegetation indicators in the study area over a 20-year period
under the low scenario with the wettest estimate of climate change.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

100%
90%
80%
S-sf
70%
Gr-sf
60%
Sed-sf
50%
SP-sf
40%
BS-ps
30%
L-ps
20%
CH-ps
10%
0% 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Figure 5-6
Proportions of the vegetation indicators in the study area over a 20-year period
under the medium scenario.

100%
80%
S-sf
Gr-sf
60%
Sed-sf
SP-sf
40%
BS-ps
L-ps
20%
CH-ps
0% 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Figure 5-7
Proportions of the vegetation indicators in the study area over a 20-year period
under the medium scenario with the driest estimate of climate change.

100%
90%
80%
S-sf
70%
Gr-sf
60%
Sed-sf
50%
SP-sf
40%
BS-ps
30%
L-ps
20%
CH-ps
10%
0% 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Figure 5-8
Proportions of the vegetation indicators in the study area over a 20-year period
under the medium scenario with the wettest estimate of climate change.

There were some slight effects evident in the delta under the low and medium scenarios, but
these were predicted to be negligible. However, under the driest climate change, these
effects would be more marked, and there will be a significant increase in savanna habitats,
and gradual terrestrialisation of the Delta. This would of course be exacerbated by water-

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E-flows Ecological and Social Predictions Scenario Report Climate Change

resource developments in the upper catchment. The wettest predicted climate change, even
with low and medium development, will result in a wetter delta than present day, and the
proportions of swamp plants are predicted to increase as a consequence.

5.4.12
Boteti (Site 8) Indicators
The indicators used for Site 8: Boteti River are:
1. Open water
2. Riparian woodland, trees.

Open water species occur in the Boteti River when the river course is inundated, when there
are isolated pools. The riparian woodland species on the other hand tend to persist for some
time (possibly as long as 50 years) even when the river is dry, as they are able to access
groundwater. Prolonged periods of no flow would, however, result in a gradual decline in
these species.

The relative extent of inundation, isolated pools and dry river bed in the Boteti River varies
with climatic variations. Under present day conditions, in wet periods as much as 100% of
the channel can become inundated and remain that way for several years. In dry periods
however, surface water in the Boteti River can dry up for extended periods, although people
are still able to access water by sinking wells into the river bed.

Impact of the Low and Medium Scenarios under Climate Change
Under the low and medium scenarios without climate change and with the wettest climate
change scenarios there was little change expected the riparian vegetation of the Boteti.
Under the driest climate change however, there will be a significant decline in the cover of
woodlands species as a result of extended periods on no-flow.

5.4.13
Summary of vegetation responses to scenarios
The riparian vegetation can loosely be divided into in-channel vegetation, floodplain-pool
vegetation, marginal vegetation, floodplain grasses and riparian trees and shrubs. In
general, the in-channel vegetation, floodplain-pool vegetation and marginal vegetation are
more dependent on lowflows and the floodplain grasses, and riparian trees and shrubs on
flood flows. The climate change predictions for the upper catchment slightly reduce the
expected impact of the low and medium developments at Sites 1, 2 and 4, but this is mainly
in the floodplains in response to expected increases in flood peak and duration. In the delta
and at Boteti, the drier climate change predictions will exacerbate the impacts of the low and
medium scenarios.

5.5. Aquatic
macroinvertebrates
5.5.1
Indicator 1: Invertebrates in channel submerged vegetation
Representative species: Crustacea (Freshwater shrimps).

Summary of characteristics
Water must always be present. At minimum flow habitat will be greatly reduced leading to
population decline as predation increases.

These invertebrates are used as indicators for Site 6.

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Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
6 PD NSC
<PD+<LS
PD NSC
NSC

5.5.2
Indicator 2: Invertebrates in channel marginal vegetation
Representative species: Crustacea (Freshwater shrimps).

Summary of characteristics
Water must always be present. High, long-duration flooding may lead to destruction of
habitat and reduction in abundance. Long duration of minimum flows restricted to the river
bed may also lead to loss of habitat.

These invertebrates are used as indicators for Sites 1, 2, 3, 4, 5, 6 and 8.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
No CC
Driest CC
Wettest CC No CC
Driest CC
Wettest CC
1 <<PD
NSC NSC <<PD
NSC NSC
2 <PD
PD+>LS
PD+>LS
<PD
<PD+>MS
PD+>MS
3 PD
NSC <PD+<LS
PD
NSC <PD+<MS
4 PD
NSC NSC PD
NSC NSC
5 PD
NSC NSC PD
NSC NSC
6 PD
NSC NSC PD
NSC NSC
7 n/a
n/a n/a n/a
n/a n/a
8 <PD
<<PD+<<LS >>PD+>>LS <PD
<<PD+<<MS >>PD+>>MS

5.5.3
Indicator 3: Invertebrates in channel fine sediments
Representative species: Unionidae, Sphaeridae.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Summary of characteristics
This group of invertebrates lives under the sediments of the river bed. They will normally
survive as long as there is some water covering the sediment. Long dry spells will reduce
abundance or even eliminate these indicators.

These invertebrates are used as indicators for Sites 1, 4, 5 and 6.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2 n/a n/a n/a n/a n/a n/a
3 n/a n/a n/a n/a n/a n/a
4
PD NSC NSC PD NSC NSC
5
PD NSC NSC PD NSC NSC
6
PD NSC NSC PD NSC NSC
7 n/a n/a n/a n/a n/a n/a
8 n/a n/a n/a n/a n/a n/a

5.5.4
Indicator 4: Invertebrates of channel cobbles and boulders
Representative species: Hydropsychidae, Ecnomidae.

Summary of characteristics
This group of indicators lives among the cobbles and boulders of rocky river beds. They will
decline in abundance and may disappear if exposed to long duration of low flows that expose
the rocks.

These invertebrates are used as indicators for Sites 2, 5 and 8.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a
n/a
n/a
n/a
n/a n/a
2 PD
NSC
NSC
PD
NSC
NSC
3 n/a
n/a
n/a
n/a
n/a n/a
4 n/a
n/a
n/a
n/a
n/a n/a
5 PD
NSC
NSC
PD
NSC
NSC
6 n/a
n/a
n/a
n/a
n/a n/a
7 <PD
<PD+<LS
PD+>LS
<PD
<<PD+<<MS NSC
8 n/a
n/a
n/a
n/a
n/a n/a

5.5.6
Indicator 6: Invertebrates in channel bedrock pools
Representative species: Dytiscidae.

Summary of characteristics
The representative species is dytiscid diving beetles that inhabit pools in bedrock. High,
long-duration flooding will destroy this habitat through constant scouring flows while long
durations of low flows may result in the pools drying out and all habitat being lost.

These invertebrates are used as indicators for Site 2.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a n/a n/a n/a n/a n/a
2
<PD
PD+>LS PD+>LS <PD
NSC
NSC
3 n/a n/a n/a n/a n/a n/a
4 n/a n/a n/a n/a n/a n/a
5 n/a n/a n/a n/a n/a n/a
6 n/a n/a n/a n/a n/a n/a
7 n/a n/a n/a n/a n/a n/a
8 n/a n/a n/a n/a n/a n/a

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.5.7
Indicator 7: Invertebrates of floodplain marginal vegetation
Representative species: Coenagrionidae, Physidae, Planorbidae.

Summary of characteristics
The species inhabit vegetation growing at the sides of wet channels. They need water at all
times. Drying out of floodplains consequent to prolonged low flows will reduce or eradicate
their habitat and their abundances will decline accordingly.

These invertebrates are used as indicators for Sites 3 and 4.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
No CC
Driest CC
Wettest CC No CC
Driest CC
Wettest CC
1 n/a
n/a n/a n/a
n/a n/a
2 n/a
n/a n/a n/a
n/a n/a
3 PD
>>PD+>>LS >>PD+>>LS PD
>>PD+>>MS >>PD+>>MS
4 <PD
PD+>LS
>PD+>LS
PD
NSC >PD+>MS
5 n/a
n/a n/a n/a
n/a n/a
6 n/a
n/a n/a n/a
n/a n/a
7 n/a
n/a n/a n/a
n/a n/a
8 n/a
n/a n/a n/a
n/a n/a

5.5.8
Indicator 8: Invertebrates of seasonal floodplain pools and backwaters
Representative species: Dytiscidae

Summary of characteristics
These species inhabit backwaters and temporary pools in seasonal floodplains. Drying out
of these areas will eradicate their habitat.

These invertebrates are used as indicators for Sites 4, 6 and 7.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
No CC
Driest CC
Wettest CC No CC
Driest CC
CC
1 n/a
n/a n/a n/a
n/a n/a
2 n/a
n/a n/a n/a
n/a n/a
3 n/a
n/a n/a n/a
n/a n/a
4 n/a
n/a n/a n/a
n/a n/a
5 n/a
n/a n/a n/a
n/a n/a
6 n/a
n/a n/a n/a
n/a n/a
7 >PD
>>PD+>>LS <PD+<LS >PD
>>PD+>>MS <PD+<MS
8 n/a
n/a n/a n/a
n/a n/a

5.5.10
Summary of aquatic invertebrate responses to scenarios
With the exception of Site 1, the Low and Medium Scenarios are expected to have a low to
negligible impact on all indicators. In the upper catchment, Sites 1 and 2, the climate change
predictions result in little or no change from the original low and medium scenarios. In the
middle and lower catchment, Sites 4, 5, 7, and 8, the wettest scenario will result in an
increase in floodplain invertebrates. In the lower catchment, however, the direst climate
change predictions will exacerbate the flow related impacts of development.

5.6. Fish
5.6.1
Indicator 1: Fish resident in river
Representative species: Tigerfish [Hydrocynus vittatus]

Summary of characteristics
This fish guild spends most of its time in the main channel, undertaking longitudinal
migrations along the river system. They require deep, clear, running water and pools
throughout the year. They respond readily to seasonal and annual flow variability, increasing
in abundance up to double their median numbers in wet years/cycles and decreasing in
abundance to possibly half their median numbers in dry years/cycles. Natural variability in
abundance is greater in the upper basin and less from Site 5 (Popa) downstream probably
due to a less flashy hydrograph. Numbers can decline to zero in the Site 8 (Boteti) as this
ephemeral river periodically dries out. Changes in the natural flow pattern, increased
turbidity and deteriorating water quality will affect this guild of fish negatively.

These fish are used as indicators for Sites 1, 2, 3, 4, 5, 6, 7 and 8.

Impact of the Low and Medium Scenarios under Climate Change

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<<PD
NSC NSC <<PD
NSC <PD+>MS
2 <PD
PD+>LS
>PD+>LS
<PD
<PD+>MS
PD+>MS
3 PD
>PD+>LS
>PD+>LS
PD
>PD+>MS
>PD+>MS
4 <PD
PD+>LS
>PD+>LS
<PD
PD+>MS
>PD+>MS
5 PD
NSC
NSC
<PD
PD+>MS
>PD+>MS
6 <PD
<PD+<LS
<PD+<LS
<PD
PD+>MS
>PD+>MS
7 <PD
<<PD+<<LS PD+>LS <PD

8 <PD
<<PD+<<LS >PD+>LS <PD

5.6.2
Indicator 2: Migratory floodplain dependent fish: small species
Representative species: Bulldog [Marcusenius macrolepidotus]

Summary of characteristics
These are small-bodied fish species that are dependent on lateral migration to floodplains for
breeding and feeding. They are resident in the river through the lowflow season and migrate
into floodplains during the flood season for feeding, breeding and protection against
predation. As a result they depend on regular flooding of shallow vegetated floodplains in the
flood season. They are also reliant on deeper [>50 cm] refuges during low flow conditions.
Major disruptions of the flooding patterns or sedimentation regimes will have a detrimental
effect on this species. However, minor changes that fall within the natural variability will not
have a major effect on these species.

These small, relatively short-lived fish can respond quickly, and increase to large numbers,
under good flooding conditions. As such their numbers are highly variable even under
present day (350-50%, and possibly even higher) as they track climatic variations in the
system.

These fish are used as indicators for Sites 1, 2, 3, 4, 5, 6 and 7.

Impact of the Low and Medium Scenarios under Climate Change

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<<PD
NSC NSC
<<PD
NSC <PD+>MS
2 <PD
<PD+>LS
>PD+>LS
<<PD
<PD+>MS <PD+>MS
3
PD
>PD+>LS >PD+>LS
PD
>PD+>MS >PD+>MS
4 <PD
PD+>LS
>PD+>LS
<PD
<PD+>MS
>PD+>MS
5
<PD
NSC PD+>LS
<PD
<PD+>MS
>PD+>MS
6
<PD
NSC PD+>LS
<PD
<PD+>MS
PD+>MS
7 <PD
<<PD+<<LS PD+>LS <PD
<<PD+<<MS NSC
8 n/a
n/a
n/a
n/a
n/a
n/a

5.6.3
Indicator 3: Migratory floodplain dependent fish: large species
Representative species: Redbreast tilapia [Tilapia rendalli]

Summary of characteristics
These are large-bodied fish species that are dependent on lateral migration to floodplains for
breeding and feeding. They are resident in the river through the lowflow season and migrate
into floodplains during the flood season for feeding, breeding and protection against
predation. As a result they depend on regular flooding of shallow vegetated floodplains in the
flood season. They are also reliant on deeper [>200 cm] refuges during low flow conditions.
Major disruptions of the flooding patterns or sedimentation regimes will have a detrimental
effect on this species. However, minor changes that fall within the natural variability will not
have any major effect on these species.

These large, relatively long-lived fish can respond quickly, and increase numbers, under
good flooding conditions, but their numbers tend to be less variable year-on-year than those
of the small-bodies counterparts (Indicator 2).

These fish are used as indicators for Sites 1, 2, 3, 4, 5, 6 and 7.

Impact of the Low and Medium Scenarios under Climate Change

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<<PD
NSC NSC
<<PD
NSC <<PD+>MS
2
<PD
<PD+>LS <PD+>LS
<PD
<PD+>MS <PD+>MS
3
PD
>PD+>LS >PD+>LS
PD
>PD+>MS >PD+>MS
4 PD
NSC NSC
PD
NSC NSC
5 n/a
n/a
n/a
n/a
n/a
n/a
6 <PD
NSC NSC
<PD
<PD+>MS
PD+>MS
7 <PD
<<PD+<<LS PD+>LS <PD
<<PD+<<MS NSC
8 n/a
n/a
n/a
n/a
n/a
n/a

5.6.5
Indicator 5: Rock dwelling fish
Representative species: Sand catlet [Leptoglanis cf dorae]

Summary of characteristics
These are rheophillic (flow-loving) species of riffles and rapids, which are usually found living
amongst the rocks and in crevices in strongly flowing water. Unlike some of the other groups
these fish tend to be resident in a particular part of the river and their numbers show much
less marked fluctuations under present day.

These fish are used as indicators for Sites 2, 4 and 5.
Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a
n/a
n/a
n/a
n/a
n/a
2
<PD
>PD+>LS PD>+>LS <PD
<PD>MS <PD>MS
3 n/a
n/a
n/a
n/a
n/a
n/a
4
<PD
PD+>LS <PD+LS <PD
NSC
NSC
5 PD NSC
<PD+<LS
PD NSC
NSC
6 n/a
n/a
n/a
n/a
n/a
n/a
7 n/a
n/a
n/a
n/a
n/a
n/a
8 n/a
n/a
n/a
n/a
n/a
n/a

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E-flows Ecological and Social Predictions Scenario Report Climate Change

5.6.6
Indicator 6: Marginal vegetation fish
Representative species: Banded tilapia [Tilapia sparrmanii].

Summary of characteristics
This group of species lives mainly amongst vegetation on margins of river and may move into
floodplains during flood conditions. As such they are depend on the presence of marginal
vegetation, stable soils and naturally varying water levels for establishment of emergent and
submerged vegetation.

These fish are used as indicators for Sites 1, 2, 3, 4, 5, 6, 7 and 8.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
No CC
Driest CC
Wettest CC No CC
Driest CC
Wettest CC
1
<<PD <<PD+>MS <<PD+>MS <<PD <<PD+>MS
<<PD+>MS
2
<PD <PD+>LS
>PD+>LS
<PD <PD+>MS <PD+>MS
3 PD >PD+>LS
>PD+>LS
PD >PD+>MS
>PD+>MS
4 PD NSC >PD+>LS
PD NSC
NSC
5 <PD
PD+>LS
>PD+>LS
<PD
<PD+>MS
>PD+>MS
6 PD
NSC >PD+>LS
<PD
PD+>MS
PD+>MS
7 <PD
<<PD+<<LS PD+>LS <PD
<<PD+<<MS
NSC
8 <PD
<PD+<LS >PD+>LS <PD
<PD+<MS >PD+>MS

5.6.7
Indicator 7: Backwater dwelling fish
Representative species: Okavango tilapia [Tilapia ruweti]

Summary of characteristics
This group of species shares a similar habitat with the marginal vegetation group but tends to
be more restricted to vegetated backwater areas and pools. They may also move into
floodplains during flood conditions. Their continued presence is dependent on the
maintenance of oxbows and pools on the margin of the floodplain of the river by the
hydrological regime, including standing-water conditions during low flow.

These fish are used as indicators for Sites 4, 6 and 7.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
No CC
Driest CC
Wettest CC No CC
Driest CC
Wettest CC
1 n/a
n/a n/a n/a
n/a n/a
2 n/a
n/a n/a n/a
n/a n/a
3 PD
>PD+>LS
>PD+>LS
PD
>PD+>MS
>PD+>MS
4 <PD
PD+>LS
>PD+>LS
<PD
<PD+>MS
PD+>MS
5 n/a
n/a n/a n/a
n/a n/a
6 <PD
NSC
>PD+>LS
<PD
<PD+>MS
PD+>MS
7 <PD
<<PD+<LS PD+>LS <PD <<PD+<MS NSC
8 n/a
n/a n/a n/a
n/a n/a

5.6.8
Summary of fish responses to scenarios
With the exception of Site 1, where fish losses are expected to be high for both scenarios,
mainly as a result of run-of-river abstraction during the lowflow season, the fish assemblages
are expected to cope fairly well with the low scenario, and slightly less well with the medium
scenario.

Under the climate change predictions, in the upper catchment (again with the exception of
Site 1), the flow impacts of water resource developments under the low and medium scenario
are significantly offset for both the driest and the wettest predictions. In the lower catchment,
however, the impacts of the low and medium scenario are significantly greater under the drier
climate change predictions, as this results in a general drying out of the lower part of the
catchment as a result of higher evaporation. Under the wetter climate change predictions,
the expected impacts in the lower catchment under the low and the medium scenario are
reduced.

5.7. Wildlife
5.7.1
Indicator 1: Semi aquatic animals
Representative species: Hippopotamus, crocodile, otters, monitors and terrapins.

Summary of characteristics
These animals dwell in the main channel, and also range over banks, floodplains and
islands. They are particularly sensitive to dry-season water depths, as they need sufficient
water to maintain their aquatic habitat but not too much so that islands are present. The DSS
predicts that they will increase in abundances in wet cycles and decrease during dry cycles.

These animals are used as indicators for all eight sites.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a
n/a n/a n/a n/a n/a
2
<PD
<PD+>LS <PD+>LS <PD
<PD+>MS <PD+>MS
3
PD
>PD+>LS >PD+>LS PD
>PD+>MS >PD+>MS
4 <PD
PD+>LS
>PD+>LS
<PD
<PD+>MS
PD+>MS
5
<PD
PD+>LS >PD+>LS
<PD
<PD+>MS >PD+>MS
6
<PD
NSC PD+>LS
<PD
<PD+>MS PD+>MS
7
PD
>PD+>LS >PD+>LS PD
>PD+>MS >PD+>MS
8
<PD
<PD+<LS >PD+>LS <PD
<<PD+<<LS >PD+>LS

5.7.4
Indicator 4: Middle floodplain grazers
Representative species: elephant, buffalo, tsesebe, warthog.

Summary of characteristics
This guild of animals depends for grazing on primary and secondary floodplains, which flood
for 2-6 months per year.

These animals are used as indicators for Sites 2, 3, 5, 7 and 8.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
No CC
Driest CC
Wettest CC No CC
Driest CC
CC
1 n/a
n/a n/a n/a n/a n/a
2 <PD
PD+>LS
>PD+>LS
<PD
NSC
<PD+>MS
3 PD
>PD+>LS
>PD+>LS
PD
>PD+>MS
>PD+>MS
4 n/a
n/a n/a n/a n/a n/a
5
<PD
>PD+>LS
>>PD+>>LS <PD
<PD+>MS >PD+>MS
6 n/a
n/a
n/a n/a
n/a
n/a
7 >PD
>PD+>LS
NSC
>PD
>PD+>MS
NSC
8 n/a
n/a n/a n/a n/a n/a

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5.7.5
Indicator 5: Outer floodplain grazers
Representative species: Wildebeest, zebra, impala, duiker, aarvark, mice.

Summary of characteristics
This group of animals relies for grazing on secondary and tertiary floodplains that must flood
periodically.

They are used as indicators for Sites 1-3 and 5-7.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
No CC
Driest CC
Wettest CC No CC
Driest CC
CC
1 <<PD
NSC
NSC <<PD
NSC NSC
2 <PD
PD+>LS
>PD+>LS
<PD
<PD+>MS
PD+>MS
3 PD
>PD+>LS
>PD+>LS
PD
>PD+>MS
>PD+>MS
4 n/a
n/a
n/a
n/a
n/a
n/a
5 <PD
PD+>LS
>>PD+>>LS <PD <PD+>MS
>PD+>MS
6 n/a
n/a
n/a
n/a
n/a
n/a
7 >PD
>PD+>LS
<PD+<LS
>PD
>PD+>MS
NSC
8 n/a
n/a
n/a
n/a
n/a
n/a

5.7.6
Summary of wildlife responses to scenarios
Abundances of wildlife are predicted to decline progressively with increasing water-resource
development. The notable exception to this is the Delta, where the three indicator groups of
grazers would benefit from the scenarios as permanent swamp gave way to seasonal
floodplains. Many of the wildlife species no longer occur at the other floodplain sites, but in
areas where they do occur, similar patterns would be expected in response to the scenarios.

In the upper catchment, these patterns would be reversed for both sets of predictions (drier
and wetter). In the lower catchment, however, specifically in the Delta and Boteti, the trends
shown for the low and medium scenarios without climate change, would be exacerbated
under the drier climate change predictions, as the increased evaporation that accompanies
these predictions would lead to the Delta becoming drier than present. Although grazers
would benefit initially as permanent swamp gave way to seasonal floodplains, they may show
an eventual decline as wetlands give way to savanna.

Under the wetter climate change predictions, some of the flow reductions as a result of
development would be offset by higher flows in the rivers, and thus a higher inflow into the
Delta and Boteti.

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5.8. Birds
5.8.1
Indicator 1: Piscivores of open water.
Representative species: kingfisher, cormorant, darter, fish eagle.

Summary of characteristics
This group of birds predominantly feeds on fish from the river and adjacent pools. They
generally thrive in times of low flow because their fish prey is more concentrated and
vulnerable in the main river and/or isolated pools. The DSS indicates that present-day
conditions produce more variability in abundances in the higher parts of the basin than in the
lower parts, and abundances are generally lower in wet years and higher in drier years. If
low flows are prolonged, however, the prey base will be negatively affected if the floodplains
where fish breed are not inundated.

These birds are used as indicators for all eight sites.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1
<PD NSC NSC <PD NSC NSC
2
>PD >PD+<LS
PD+<LS
>PD >PD+<MS
PD+<MS
3 PD NSC
>PD+>LS
PD NSC >PD+>MS
4 >PD
>PD+<LS
PD+<LS
>PD
>PD+<MS PD+<MS
5
PD NSC NSC PD NSC NSC
6 PD
NSC
NSC
>PD
PD+<MS <PD+<MS
7
>PD
>PD+>LS >PD+>LS >PD
>PD+>MS NSC
8
<PD
<PD+<LS >PD+>LS <PD
<<PD+<MS >PD+>MS

5.8.2
Indicator 2: Piscivores of shallow waters
Representative species: larger herons and egrets.

Summary of characteristics
These birds hunt fish from overhanging trees on shallow backwaters using ambush
techniques. Under Present Day conditions, the DSS indicates that their numbers tend to be
lower in drier years, with good variability from year to year and many years with above
median abundances. In the lower part of the basin they are less abundant in the lagoon and
savanna parts of the Delta/Boteti and rather favour the seasonally flooded areas. Shallow
waters in the main channels and on the floodplains concentrate the prey species into smaller
areas and hunting opportunities are thus better than in lagoon areas.

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These birds are used as indicators for all eight sites.

Impact of the Low and Medium Scenarios under Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
No CC
Driest CC
Wettest CC No CC
Driest CC
Wettest CC
1
<<PD
NSC NSC <<PD
NSC NSC
2
<<PD <PD+>LS
PD+<LS <<PD <PD+>MS
<PD+>MS
3 PD
>PD+>LS
>>PD+>>LS PD >PD+>MS
>PD+>MS
4
>PD PD+<LS
PD+<LS
>PD PD+<MS
PD+<MS
5 PD NSC <PD+<LS
PD NSC <PD+<MS
6
>PD PD+<LS
<PD+<LS
>PD >PD+<MS
PD+<MS
7
>PD >PD+>LS
NSC >PD >PD+>MS
>PD+>MS
8 <PD
<PD+<LS
PD+>LS
<PD
<<PD+<MS
PD+>MS

5.8.3
Indicator 3: Piscivores and invertebrate feeders
Representative species: Little Egret, Black Heron, Glossy Ibis, Saddle-billed Stork, Lapwings.

Summary of characteristics
This group of birds feeds on fish-fry and invertebrates when water levels are receding after
spawning in flood-plains; they also feed on fish trapped in drying pools. They respond to the
flooding and draining of floodplains, when feeding conditions are optimal, and tend to be
more abundant in wetter years.

These birds are used as indicators for all eight sites.

Impact of the Low and Medium Scenarios under Climate Change

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E-flows Ecological and Social Predictions Scenario Report Climate Change

`No CC' columns are relative to Present Day. `Driest CC' and `Wettest CC' columns
are relative to relevant `No CC' scenario. NSC = no significant change. PD = Present
Day. LS = low scenario. MS = medium scenario. </> = slightly different; <</>> =
significantly different
Low scenario
Medium scenario
Site
Wettest
Wettest
No CC
Driest CC
No CC
Driest CC
CC
CC
1 n/a n/a n/a n/a n/a n/a
2
PD NSC NSC PD NSC NSC
3
PD
>PD+>LS >PD+>LS PD
>PD+>MS >PD+>MS
4
<PD PD+>LS
>PD+>LS
<PD NSC >PD+>MS
5
PD NSC NSC PD NSC NSC
6
PD NSC NSC <PD NSC PD+>MS
7 PD
>PD+>LS
NSC
>PD
>PD+>MS
>PD+>MS
8
<PD
<PD+<LS >PD+>LS <PD
<<PD+<LS >PD+>MS

5.8.6
Indicator 6: Specialists inhabitants of riparian fruit trees
Representative species: Turacos, bulbuls.

Summary of characteristics
This group of birds are specialist frugivores in riparian fruit trees; when the trees are in fruit
they are an important food source for many bird species. The birds are indirectly influenced
by changes in water flows because they depend on the fruit-bearing riparian trees, which in
turn respond to changes in water flows. Because most of the trees are long-lived, there will
be a time lag of several years after the onset of unfavourable flows before fruit production
fails and the trees start dying from lack of water. Abundance of the birds should mirror to
some extent that of the trees since if the trees die due to low flows, there will not be a source
of food for the birds.

These birds are used as indicators for Sites 2-7.

Impact of the Low and Medium Scenarios under Climate Change

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E-flows Ecological and Social Predictions Scenario Report Climate Change

6.
Biophysical results: Integrity
6.1.
Integrity ratings and classification of overall impact
The predictions presented in the previous Chapter were generated from the information
provided by the biophysical specialists in the form of Response Curves. This is essentially a
set of consequences for a particular indicator to changes in a range of flow categories
expressed as Severity Ratings of that describe increase/decreases for an indictor on a scale
of 0 (no measurable change) to 5 (very large change; see Section 1.3). These rating were
then taken further to indicate whether that change would be a shift toward or away from the
natural condition. The Severity Ratings hold their original numerical value of between 0 and
5, but are given an additional negative or positive sign, to transform them from Severity
Ratings (of changes in abundance or extent) to Integrity Ratings (of shift to/away from
naturalness), where (Brown and Joubert 2003):
· toward natural is represented by a positive Integrity Rating; and
· away from natural is represented by a negative Integrity Rating.

The Integrity Ratings were then used to place the three flow scenarios within a classification
of overall discipline integrity and overall river condition, using the South African
ecoclassification categories A to F (Table 6.1; DWAF 1999; Kleynhans 1996; Brown and
Joubert 2003). The ecological integrity of a river is defined as its ability to support and
maintain a balanced, integrated composition of physico-chemical and habitat characteristics,
as well as biotic components on a temporal and spatial scale that are comparable to the
natural characteristics of ecosystems of the region.

Table 6.1.
The South African River Categories (DWAF 1999)
CATEGORY DESCRIPTION
A Unmodified,
natural.
Largely natural with few modifications. A small change in natural habitats and
B
biota may have taken place but the ecosystem functions are essentially
unchanged.
Moderately modified. A loss and change of natural habitat and biota have
C
occurred but the basic ecosystem functions are still predominantly unchanged.
Largely modified. A large loss of natural habitat, biota and basic ecosystem
D
functions has occurred.
E
The loss of natural habitat, biota and basic ecosystem functions is extensive.
Modifications have reached a critical level and the lotic system has been modified
completely with an almost complete loss of natural habitat and biota. In the worst
F
instances the basic ecosystem functions have been destroyed and the changes
are irreversible.

Note : A D-category is widely considered to represent the lower limit of degradation
allowable under sustainable development (e.g., Dollar et al. 2006; Dollar et al. In
press).

In this study, the predictions provided by the specialists for each of the three were
summarized in terms of their effects on the integrity of each discipline at each study site and
the overall riverine ecosystem represented by each study site. If the present status of a river
is say a B-category, a scenario with a negative Integrity Score would represent movement in
the direction of a Category C-F river, whilst one with a positive score would indicate
movement toward a Category A river.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

6.2.
Present-day ecological integrity for the study sites
The present day ecological integrity of the aquatic ecosystems at each of the eight study
sites was determined using a Habitat Integrity Assessment (Kleynhans 1996). The Habitat
Integrity Method uses easily assessed physico-chemical and habitat characteristics as
surrogates for physical and biotic condition. The method is based on the qualitative
assessment of a number of pre-weighted criteria that indicate the integrity of the instream
and riparian habitats available for use by riverine biota (Table 6.2). The criteria used are the
basis that anthropogenic modification of their characteristics can generally be regarded as
the primary causes of degradation of the integrity of a river.

The assessment of the severity of impact of modifications is based on six descriptive
categories with ratings ranging from 0 (no impact), 1 to 5 (small impact), 6 to 10 (moderate
impact), 11 to 15 (large impact), 16 to 20 (serious impact) and 21 to 25 (critical impact).

The assessment was done using the professional judgement and experience of the study
team, and was conducted on-site at each of the study sites. Assessments were made
separately for instream and riparian components, and then combined and expressed as a
percentage and subtracted from 100 to produce a score for overall Habitat Integrity.

Table 6.2
Criteria and weights used for the assessment (from Kleynhans 1996).
INSTREAM CRITERIA
WEIGHT RIPARIAN ZONE CRITERIA
WEIGHT
Water abstraction
14
Indigenous vegetation removal
13
Flow modification
13
Exotic vegetation encroachment 12
Bed modification
13
Bank erosion
14
Channel modification
13
Channel modification
12
Water quality
14
Water abstraction
13
Inundation
10
Inundation
11
Exotic macrophytes
9
Flow modification
12
Exotic fauna
8
Water quality
13
Solid waste disposal
6

TOTAL 100
TOTAL
100

The results of the assessments are presented in Table 6.3. The total scores for the instream
and riparian zone components are then used to place the habitat integrity of both in a specific
intermediate habitat integrity category. These categories are also indicated in Table 6.3.

88

Table 6.3
Results of the Habitat Integrity (after Kleynhans 1996) assessments done on-site by the biophysical specialists at each of the study sites
(October 2008)
y
y

s
nt
n

io

me

hyte
h
tegor
Integrit

ws
al
r

r
a
ct
nel
e
st

a
bitat
b
a
st
mov
Site No
Rive
Place
PD Ca
H
Instream
Riparian
A
Quality
Floods
Lowflo
Bed
Chan
Inundation
Macrop
Fish
W
Re
Encroac
Erosion
1 Cuebe Capico
B 84.1 91.7
76.48 8 0 0 5 0 5 0 0 0 0 18 0 5
2 Cubango
Mucundi
B
87.3 92.8
81.76 6 0 0 5 0 5 0 0 0 0 16 0 0
3 Cuito Cuito
Cuanavale
B
91.0 93.5
88.52 0 1 0 5 1 5 1 0 0 5 12 0 0
4 Okavango
Kapako
B
86.2 86.6
85.72 5 7 0 0 8 0 0 1 0 9 16 1 0
5 Okavango
Popa
Falls B
91.2 92.6
89.72 2 3 0 0 0 1 0 0 0 17 11 0 2
6 Okavango
Panhandle B
93.5 96.7
90.28 2 2 0 0 0 2 0 0 0 0 11 0 0
7 Okavango
Xaxanaka B
98.6 98.3
98.88 2 1 0 0 0 0 0 0 0 0 0 0 0
8 Boteti Maun
B
88.2 88.5
87.88 6 6 0 4 3 3 0 2 0 0 9 0 0

Where:
A Category = 100
B Category = 80-99
C Category = 60-79
D Category = 40-59
E Category = 20-39
F Category = 0-19.

89

Additional details for the method used are provided in Report 03/2009: Guidelines for data
collection, analysis and scenario creation.

6.3.
Interpretation of integrity plots
The integrity plots presented in this Chapter list each of the study sites (1-8) along the x-axis,
and the Overall Integrity Rating on the y-axis. Zero on the y-axis equals the present day
integrity of the system. Since all of the study sites have a present-day integrity of a B
category, zero on the y-axis equals a B-category.

There is a series of lines marked on the integrity plot representing the general position on the
graph when the overall integrity ratings would be expected to result in a move from one
category to the next.

6.4.
Effects on the integrity of each discipline
The present-day (2008) integrity was a B-category for all disciplines.

6.4.1 Geomorphology
The integrity plot for geomorphology for the low and medium scenarios, with and without
climate change, at each of the study sites is shown in Figure 6-1.

The impacts on geomorphological integrity for the low and medium scenarios under the two
levels of climate change can be summarised as follows:

Site 1 (Capico):
Drop of two categories from a B-category to a D-category for
both low and medium scenarios. The driest climate change
predictions have no appreciable effect on this, but the wetter
predictions reduce the drop to one and a half categories, i.e.,
from a B-Category to C/D-Category.
Site 2 (Mucundi):
For the low scenario, the driest climate change pedictions would
improve the overall condition by about half a category, but it
would remain in a C-Category. The wettest climate change
predictions would offset most of the flow related impacts, and
the system would be in a B-category (i.e., present day
condition). There is a similar pattern of the medium scenario,
although both would still result in a C-category.
Site 3 (Cuito Cuanavale):
No change.
Site 4 (Kapako):
A drop of half a category to a B/C for the low scenario, and a
drop of two categories to a C-category for the medium scenario.
The driest climate change predictions would reduce this by half
a catgeory for both scenarios. The wettest climate change
predictions would offset the flow related effects of development
at Kapako.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Geomorphology
2
1
ing
0 PD
PD
r
i
t
y
Rat
-1
eg
nt
l I
al
-2
v
er
O
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-1
Integrity plot for geomorphology for the low and medium scenarios, with and
without climate change, at each of the study sites

Site 5 (Popa Falls):
No change in category.
Site 6 (Panhandle):
No change in category.
Site 7 (Xaxanaka):
Without climate change there is no change for the low and
medium scenarios. Under the driest climate change predictions
this would change to a one-category drop from a B-category to
a C-category.
Site 8 (Boteti):
Geomorphology not assessed for the Boteti.

6.4.2 Water
Quality
The integrity plot for water quality for the low and medium scenarios, with and without climate
change, at each of the study sites is shown in Figure 6-2.

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Water Quality
2
1
g
0
ti
n
PD
PD
a
R
r
i
ty
g
-1
t
e
l
l
In
r
a
-2
v
e
O
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-2
Integrity plot for water quality for the low and medium scenarios, with and
without climate change, at each of the study sites

The impacts on water quality integrity for the low and medium scenarios under the two levels
of climate change can be summarised as follows:
Site 1 (Capico):
Drop of two categories from a B-category to a D-category for
low and medium scenarios. The predicted climate change will
have no appreciable effect on this.
Site 2 (Mucundi):
The drop of half a category from a B-category to a B/C-category
for the low and medium scenarios without climate change
reduce by a half and a full category under the driest and wettest
climate change predictions, respectively.
Site 3 (Cuito Cuanavale):
No change.
Site 4 (Kapako):
The predicted climate change will offset the flow related impacts
of the low scenario. The wettest climate change predictions
would also offset the flow related impacts of the medium
scenario. However the driest climate change predictions would
mean that the river at Kapako dropped to a C-category in the
medium scenario.
Site 5 (Popa Falls):
The predicted climate change will offset the flow related impacts
of the low and medium scenarios.
Site 6 (Panhandle):
The predicted climate change would have very slight
ameliorating effect on the flow related impacts on the low and
medium scenarios. The medium scenario without climate
change and the medium scenario with driest climate change,
would drop to a C-category.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Site 7 (Xaxanaka):
The limited effects of the low and medium scenarios without
climate change would increase by a full category drop under the
driest climate change predictions. Thus for the low scenario the
Delta would be in a C-category and for the medium scenario, it
would be in a D-category.
Site 8 (Boteti):
No significant change in water quality, mainly because the river
is predominately dry under the medium and high scenarios
without climate change and under the driest predictions. The
river would flow more frequently, and water quality would
improve from present, under the wetter climate change
predictions.

6.4.3 Vegetation
The integrity plot for vegetation for the low and medium scenarios, with and without climate
change, at each of the study sites is shown in Figure 6-3.

Vegetation
2
1
g
0
ti
n
PD
PD
a
R
r
i
ty
g
-1
te
l
l
In
r
a
e
-2
Ov
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-3
Integrity plot for vegetation for the low and medium scenarios, with and without
climate change, at each of the study sites

The impacts on vegetation integrity for the low and medium scenarios under the two levels of
climate change can be summarised as follows:
Site 1 (Capico):
Drop of two categories from a B-category to a D-category for all
scenarios. The predicted climate change will have no
appreciable effect on this.
Site 2 (Mucundi):
The driest and wettest climate change will mean that the flow
changes as a result of the low scenario will have little or no

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E-flows Ecological and Social Predictions Scenario Report Climate Change

effect onthe vegetation at Mucundi. For the medium scenario,
under the driest climate change predictions the river will be in a
B/C-category instread of the D-category under no climate
change, and ther wettest climate change will mean that the flow
changes as a result of the medium scenario will have little or no
overall effect on vegetation.
Site 3 (Cuito Cuanavale):
No change.
Site 4 (Kapako):
The predicted climate change will offset the flow related impacts
of the low and medium scenarios.
Site 5 (Popa Falls):
No change.
Site 6 (Panhandle):
No change.
Site 7 (Xaxanaka):
The limited effects of the low and medium scenarios without
climate change would increase by a full category drop under the
driest climate change predictions. This would mean the Delta
would be in a C-category for both the low and medium
scenarios.
Site 8 (Boteti):
The drier climate change scenario will exacerbate the impacts
of water-resource development on vegetation in the Boteti. The
wettest climate change predictions would offset these impacts.

6.4.4 Aquatic
macroinvertebrates
The integrity plot for aquatic macroinvertebrates for the low and medium scenarios, with and
without climate change, at each of the study sites is shown in Figure 6-4.

The impacts on aquatic macroinvertebrate integrity for the low and medium scenarios under
the two levels of climate change can be summarised as follows:
Site 1 (Capico):
No change.
Site 2 (Mucundi):
No change.
Site 3 (Cuito Cuanavale):
No change.
Site 4 (Kapako):
No change.
Site 5 (Popa Falls):
No change.
Site 6 (Panhandle):
No change.
Site 7 (Xaxanaka):
The limited effects of the low and medium scenarios without
climate change would increase by a full category drop under the
driest climate change predictions. This would mean the Delta
would be in a C-category for both the low and medium
scenarios.

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Macroinvertebrates
2
1
g
0
ti
n
PD
PD
a
R
r
i
ty
g
-1
te
l
l
In
r
a
e
-2
Ov
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-4
Integrity plot for aquatic macroinvertebrates for the low and medium scenarios,
with and without climate change, at each of the study sites

Site 8 (Boteti):
The drier climate change scenario will exacerbate the impacts
of water-resource development on macroinvertebrates in the
Boteti. The wettest climate change predictions would offset
these impacts.

6.4.5 Fish
The integrity plot for fish for the low and medium scenarios, with and without climate change,
at each of the study sites is shown in Figure 6-5.

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E-flows Ecological and Social Predictions Scenario Report Climate Change

Fish
2
1
0
t
i
ng
PD
PD
i
t
y
Ra
gr
-1
t
e
n
l I
r
al
-2
v
e
O
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-5
Integrity plot for fish for the low and medium scenarios, with and without
climate change, at each of the study sites

The impacts on fish integrity for the low and medium scenarios under the two levels of
climate change can be summarised as follows:
Site 1 (Capico):
The drop of four categories from a B-category to an F-category
for the low and medium scenarios is not affected by climate
change.
Site 2 (Mucundi):
The driest and wettest predicted climate change will offset the
flow related impacts of the low scenario. For the medium
scenario, the wettest climate change predictions will mean a
B/C-category instead of a D-category, and the driest predictions
a C-category instead of a D-category.
Site 3 (Cuito Cuanavale):
Wetter conditions at Cuito would mean more fish.
Site 4 (Kapako):
The driest and wettest predicted climate change will offset the
flow related impacts of the low scenario. They wettest will also
offset the flow related impacts of the medium scenario. The
driest will partly offset the impacts resulting in a C-category
instead of a B-category.
Site 5 (Popa Falls):
The predicted climate change will offset the flow related impacts
of the low and medium scenarios.
Site 6 (Panhandle):
The wettest climate change predictions will offset the the flow
related impacts of the low and medium scenarios. The driest
predicted will have little effect.

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Site 7 (Xaxanaka):
The limited negative effects of the low and medium scenarios
without climate change would increase by a two full categories
under the driest climate change predictions. This would mean
the Delta would be in an a D- and E-category for the low and
medium scenarios, respectively.
Site 8 (Boteti):
The wettest climate change predictions would be positive for
fish in the Boteti, but the driest predictions mean that even
under low scenario the fish community in the Boteti is in an E-
category.

6.4.6 Wildlife
The integrity plot for wildlife for the low and medium scenarios, with and without climate
change, at each of the study sites is shown in Figure 6-6.

Wildlife
2
1
i
ng
0 PD
PD
at
i
t
y
R
-1
egr
nt
l I
al
-2
v
er
O
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-6
Integrity plot for wildlife for the low and medium scenarios, with and without
climate change, at each of the study sites

The impacts on wildlife integrity for the low and medium scenarios under the two levels of
climate change can be summarised as follows:
Site 1 (Capico):
The drop of four categories from a B-category to an F-category
for the low and medium scenarios would be slightly offset by the
wettest climate change predictions.

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Site 2 (Mucundi):
The driest and wettest predicted climate change will offset the
flow related impacts of the low scenario. For the medium
scenario, the wettest climate change predictions will mean a
B/C-category instead of a D-category, and the driest a C-
category instead of a D-category.
Site 3 (Cuito Cuanavale):
The wetter conditions under climate change will means less
grazing for wildlife.
Site 4 (Kapako):
The driest and wettest predicted climate change will offset the
flow related impacts of the low and medium scenarios.
Site 5 (Popa Falls):
The driest and wettest predicted climate change will offset the
flow related impacts of the low and medium scenarios.
Site 6 (Panhandle):
The driest and wettest predicted climate change will offset the
flow related impacts of the low and medium scenarios.
Site 7 (Xaxanaka):
No change major change for the low and medium scenarios
without climate change or under the wettest climate change,
however, the driest climate change will lead to a drop of one
category to a C-Category for the medium scenario.
Site 8 (Boteti):
The drier climate change scenario will exacerbate the impacts
of water-resource development on macroinvertebrates in the
Boteti. The wettest climate change predictions would offset
these impacts.

6.4.7 Birds
The integrity plot for birds for the low and medium scenarios, with and without climate
change, at each of the study sites is shown in Figure 6-7.

The impacts on bird integrity for the low and medium scenarios under the two levels of
climate change can be summarised as follows:
Site 1 (Capico):
Drop of three categories from a B-category to an E-category for
all scenarios. The predicted climate change will have no
appreciable effect on this.
Site 2 (Mucundi):
The driest and wettest predicted climate change will offset the
flow related impacts of the low scenario. For the medium
scenario, the wettest climate change predictions will mean a
B/C-category instead of a D-category, but the driest predictions
will not improve on the D-category.
Site 3 (Cuito Cuanavale):
No change.
Site 4 (Kapako):
The driest and wettest predicted climate change will offset the
flow related impacts of the low and medium scenarios.

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Birds
2
1
ing
0 PD
PD
i
t
y
Rat
-1
egr
nt
l I
al
-2
v
er
O
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-7
Integrity plot for birds for the low and medium scenarios, with and without
climate change, at each of the study sites

Site 5 (Popa Falls):
The driest and wettest predicted climate change will offset the
flow related impacts of the low and medium scenarios.
Site 6 (Panhandle):
The driest and wettest predicted climate change will offset the
flow related impacts of the low and medium scenarios.
Site 7 (Xaxanaka):
The relatively minor effect of the low and medium scenario
without climate change increase to a one-category drop under
the driest climate change predictions. This does not, however,
mean that there will be fewer birds, only fewer of the species
that are dependent on open water and swamp land.
Site 8 (Boteti):
The drier climate change scenario will exacerbate the impacts
of water-resource development on macroinvertebrates in the
Boteti, such as loss of water-dependent birds. The wettest
climate change predictions would offset these impacts.

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6.5.
Effects on the integrity of the whole ecosystem
The plot for overall ecosystem integrity for the low and medium scenarios, with and without
climate change, at each of the study sites is shown in Figure 6-8.

Please note: In Figure 6-8, the integrity scores greater than 0 may denote an improvement
back towards natural conditions, but more likely denote a change in the overall ecosystem
towards one that is wetter than it has been in the recent past.

OVERALL INTEGRITY
2
1
0
-1
-2
-3
-4
-5
SITE 1
SITE 2
SITE 3
SITE 4
SITE 5
SITE 6
SITE 7
SITE 8
PD Sim
Low Dev
Low-CC Driest
Low-CC Wettest
Med Dev
Med-CC Driest
Med-CC Wettest
B to C
C to D
D to E
E to F

Figure 6-8
Overall ecosystem integrity for the low and medium scenarios, with and without
climate change, at each of the study sites

The impacts on overall ecosystem integrity for the low and medium scenarios under the two
levels of climate change can be summarised as follows:
Site 1 (Capico):
The drop of three categories to a E-category for the medium
and low scenarios, was reduced slightly to a D/E-category
under the wettest climate change predictions, but there was no
significant difference under the drier climate change predictions.
Site 2 (Mucundi):
Under the low and medium the condition of the system dropped
from a B-category to a C-category. For the low scenario both
climate change prediction levels result in a return to a B-
category. For the medium scenario, there is no significant
change in overal condition under the driest predictions, but

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there is an improvement to a B-category under the wettest
predictions.
Site 3 (Cuito Cuanavale):
No change.
Site 4 (Kapako):
The driest and wettest climate change will mean that the flow
changes as a result of the low scenario will have little or no
effect on ecosystem condition. For the medium scenario, under
the driest climate change predictions the river will be in a low B-
category instread of the C-category under no climate change,
and ther wettest climate change will mean that the flow changes
as a result of the medium scenario will have little or no effect on
ecosystem condition.
Site 5 (Popa Falls):
The climate change prediction would mean that the flow
changes as a result of the low and medium scenarios will have
little or no effect on ecosystem condition.
Site 6 (Panhandle):
The climate change prediction would mean that the flow
changes as a result of the low and medium scenarios will have
little or no effect on ecosystem condition.
Site 7 (Xaxanaka):
The wettest climate change prediction would mean that the flow
changes as a result of the low and medium scenarios will have
little or no effect on ecosystem condition. However, the driest
climate change prediction under both the low and medium
scenarios would result in significantly greater decline that for the
medium scenario without climate change. This is because, in
Botswana, the overall effect of the drier climate change
prediction is towards a drier ecosystem.
Site 8 (Boteti):
The pattern of the Boteti is similar to that for the Delta, i.e., the
drier climate change scenario will exacerbate the impacts of
water-resource development on the Boteti. The wettest climate
change predictions would offset these impacts.

The most striking aspect of the climate change predictions is the possible exacerbation of
flow-related impacts in the Delta and Boteti, if the drier climate change prediction occurs.
These are particularly acute for the medium scenario where the condition of the Delta and
Boteti will two and three categories lower than at present, respectively. Under the medium
scenario, this means that the Boteti will cease to flow in most years in a forty-year sequence,
and there will be considerable terrestrialisation of the Delta. This is equivalent to the
predicted impacts for high development without climate change (see Volume 1). This be less
severe under the low scenario and is not expected to occur if water-resource development
stays at present day levels.

In Figure 6-9, those sections of the river in a D-category and in an E-category have been
marked with a red flag. This is because the expected decline in their condition is likely to
result in difficulties in sustaining the benefits offered by theses ecosystems. This is
particularly so given the fact that neither the localised impacts of the water-resource
developments themselves (such as sediment changes) nor the longitudinal impacts of a
fragmented river system have been considered in these predictions.

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Low
Medium
No CC
CCD
CCW
No CC
CCD
CCW
A
B
C
D
E

Figure 6-9
Summary of expected changes in ecosystem integrity for the low and medium
scenarios under the two levels of climate change. Present-day conditions are
estimated as B-category. No CC = without climate change; CCD = driest climate
change predictions; CCW = wettest climate change predictions.

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7. Social
results

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8. Conclusions
Scenarios describe the impacts of the specific developments that were chosen for
consideration, and any other permutation making up a particular level of development (low,
medium or high in this case) would not necessarily have the described impacts. A different
arrangement of proposed water-resource schemes could produce different impacts. Altering
the development placed in the hydrological model upstream of Capico, for instance, so that
more water would continue to flow down the river in the dry season, could greatly reduce the
predicted impact at that site. This highlights the value of the DSS, which has been set up to
be queried, and to provide predictions of the impact of, any permutation of possible
developments.

In this project, the EFlow Assessment was preliminary, based on available information, and
the predictions are thus of low confidence. It sets the scene for a Phase 2 research-based
EFlow Assessment, where major data gaps can be addressed, models improved, more
scenarios and sites investigated, and higher-confidence predictions produced. Such a Phase
2 would also incorporate an improved DSS with indicators linked in series to better show the
domino effect of changing flows through hydraulic and water-quality changes, to impacts on
the vegetation, then the fauna, then people.

The EF Scenarios focused on changes that were considered likely through potential changes
in flow patterns. Impacts of constructing and operating water-resource infrastructure were
not addressed, nor were knock-on effects such as increased agricultural return flows
potentially laden with pesticide residues and fertilisers. Another aspect not addressed
because of the lack of data and models, yet vitally important, is the sediment dynamics of the
system and how flow changes and in-channel dams could change the movement of
sediments through the system and thus the character of the channels, floodplains and delta.

Social aspects not addressed

In the previous assessments (see Volume 1), the low scenario presented few risks for the
basin but there was some risk that the medium scenario would result in severe degradation
at some points in the basin. Importantly, the impacts associated with both the low and
medium scenarios were predominately in-country. With climate change added as an overlay,
there are two possible future paths:
· The drier climate change predictions, which would reduce the localized impacts and
would increase the impacts in the lower catchment, i.e., the Delta and Boteti.
· The wetter climate change predictions, which would ameliorate the flow-related impacts
of development throughout the Delta.

Impacts on people

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9. References
Adamson, P. 2006. Hydrological background and the generation of exploratory flow regimes
for the development of the impact analysis tools. Integrated Basin Flow
Management. Internal Report of the Mekong River Commission, Laos PDR.
45 pp.
Brown, C.A. and Joubert, A.R. 2003. Using multicriteria analysis to develop environmental
flow scenarios for rivers targeted for water-resource development. Water SA
Vol. 29 (No. 4).
Department of Water Affairs and Forestry. 1999. Resource Directed Measures for the
Protection of Water Resources. Version 1.0. Pretoria, South Africa.
Dollar, E.S.J., Brown, C.A., Turpie, J.K., Joubert, A.R., Nicolson, C.R. and Manyaka, S.M.
2006: The development of the Water Resource Classification System
(WRCS). Volume 1. Overview and 7-step classification procedure. CSIR
Report No., Department of Water Affairs and Forestry, Pretoria, 70pp.
Dollar, E.S.J, Nicolson, C.R., Brown, C.A., Turpie, J.K., Joubert, A.R, Turton, A.R., Grobler,
D.F. and Manyaka, S.M. In press. The development of the South African
Water Resource Classification System (WRCS): a tool towards the
sustainable, equitable and efficient use of water resources in a developing
country. Water Policy..
King, J.M., Brown, C.A. and Sabet, H. 2003. A scenario-based holistic approach to
environmental flow assessments for regulated rivers. Rivers Research and
Applications 19 (5-6). Pg 619-640.
Kleynhans, C.J. 1996. A qualitative procedure for the assessment of the habitat integrity
status of the Luvuvhu River. Journal of Aquatic Ecosystem Health 5: 41 - 54.

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The Okavango River Basin Transboundary Diagnostic Analysis Technical Reports

In 1994, the three riparian countries of the
Analysis to establish a base of available scientific
Okavango River Basin Angola, Botswana and
evidence to guide future decision making. The
Namibia agreed to plan for collaborative
study, created from inputs from multi-disciplinary
management of the natural resources of the
teams in each country, with specialists in hydrology,
Okavango, forming the Permanent Okavango River
hydraulics, channel form, water quality, vegetation,
Basin Water Commission (OKACOM). In 2003, with
aquatic invertebrates, fish, birds, river-dependent
funding from the Global Environment Facility,
terrestrial wildlife, resource economics and socio-
OKACOM launched the Environmental Protection
cultural issues, was coordinated and managed by a
and Sustainable Management of the Okavango
group of specialists from the southern African region
River Basin (EPSMO) Project to coordinate
in 2008 and 2009.
development and to anticipate and address threats

to the river and the associated communities and
The following specialist technical reports were
environment. Implemented by the United Nations
produced as part of this process and form
Development Program and executed by the United
substantive background content for the Okavango
Nations Food and Agriculture Organization, the
River Basin Transboundary Diagnostic Analysis.
project produced the Transboundary Diagnostic

Final Study
Reports integrating findings from all country and background reports, and covering the entire
Reports
basin.

Aylward, B.
Economic Valuation of Basin Resources: Final Report to
EPSMO Project of the UN Food & Agriculture Organization as
an Input to the Okavango River Basin Transboundary
Diagnostic Analysis

Barnes, J. et al.
Okavango River Basin Transboundary Diagnostic Analysis:
Socio-Economic Assessment Final Report

King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment Project
C.A.
Initiation Report (Report No: 01/2009)

King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment EFA
C.A.
Process Report (Report No: 02/2009)

King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Guidelines for Data Collection, Analysis and Scenario Creation
(Report No: 03/2009)

Bethune,
S.
Mazvimavi,
Okavango River Basin Environmental Flow Assessment
D. and Quintino, M.
Delineation Report (Report No: 04/2009)

Beuster, H.
Okavango River Basin Environmental Flow Assessment
Hydrology Report: Data And Models(Report No: 05/2009)

Beuster,
H. Okavango River Basin Environmental Flow Assessment
Scenario Report : Hydrology (Report No: 06/2009)

Jones, M.J.
The Groundwater Hydrology of The Okavango Basin (FAO
Internal Report, April 2010)

King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Scenario Report: Ecological and Social Predictions (Volume 1
of 4)(Report No. 07/2009)

King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Scenario Report: Ecological and Social Predictions (Volume 2
of 4: Indicator results) (Report No. 07/2009)

King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Scenario Report: Ecological and Social Predictions: Climate
Change Scenarios (Volume 3 of 4) (Report No. 07/2009)

King, J., Brown, C.A.,
Okavango River Basin Environmental Flow Assessment
Joubert, A.R. and
Scenario Report: Biophysical Predictions (Volume 4 of 4:
Barnes, J.
Climate Change Indicator Results) (Report No: 07/2009)

King, J., Brown, C.A.
Okavango River Basin Environmental Flow Assessment Project
and Barnes, J.
Final Report (Report No: 08/2009)

Malzbender, D.
Environmental Protection And Sustainable Management Of The
Okavango River Basin (EPSMO): Governance Review

Vanderpost, C. and
Database and GIS design for an expanded Okavango Basin
Dhliwayo, M.
Information System (OBIS)

Veríssimo, Luis
GIS Database for the Environment Protection and Sustainable
Management of the Okavango River Basin Project

Wolski,
P.
Assessment of hydrological effects of climate change in the
Okavango Basin

Country Reports
Angola
Andrade e Sousa,
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Biophysical Series
Helder André de
Okavango: Módulo do Caudal Ambiental: Relatório do

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Especialista: País: Angola: Disciplina: Sedimentologia &
Geomorfologia

Gomes, Amândio
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Okavango: Módulo do Caudal Ambiental: Relatório do
Especialista: País: Angola: Disciplina: Vegetação

Gomes,
Amândio
Análise Técnica, Biofísica e Socio-Económica do Lado
Angolano da Bacia Hidrográfica do Rio Cubango: Relatório
Final:Vegetação da Parte Angolana da Bacia Hidrográfica Do
Rio Cubango

Livramento, Filomena
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Okavango: Módulo do Caudal Ambiental: Relatório do
Especialista: País: Angola: Disciplina:Macroinvertebrados

Miguel, Gabriel Luís
Análise Técnica, Biofísica E Sócio-Económica do Lado
Angolano da Bacia Hidrográfica do Rio Cubango:
Subsídio Para o Conhecimento Hidrogeológico
Relatório de Hidrogeologia

Morais, Miguel
Análise Diagnóstica Transfronteiriça da Bacia do Análise Rio
Cubango (Okavango): Módulo da Avaliação do Caudal
Ambiental: Relatório do Especialista País: Angola Disciplina:
Ictiofauna

Morais,
Miguel
Análise Técnica, Biófisica e Sócio-Económica do Lado
Angolano da Bacia Hidrográfica do Rio Cubango: Relatório
Final: Peixes e Pesca Fluvial da Bacia do Okavango em Angola

Pereira, Maria João
Qualidade da Água, no Lado Angolano da Bacia Hidrográfica
do Rio Cubango

Santos,
Carmen
Ivelize
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Van-Dúnem S. N.
Okavango: Módulo do Caudal Ambiental: Relatório de
Especialidade: Angola: Vida Selvagem

Santos, Carmen Ivelize
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Van-Dúnem S.N.
Okavango:Módulo Avaliação do Caudal Ambiental: Relatório de
Especialidade: Angola: Aves

Botswana Bonyongo, M.C.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Botswana: Discipline: Wildlife

Hancock, P.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module : Specialist Report: Country:
Botswana: Discipline: Birds

Mosepele,
K. Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Botswana: Discipline: Fish

Mosepele, B. and
Okavango River Basin Technical Diagnostic Analysis:
Dallas, Helen
Environmental Flow Module: Specialist Report: Country:
Botswana: Discipline: Aquatic Macro Invertebrates

Namibia
Collin Christian &
Okavango River Basin: Transboundary Diagnostic Analysis
Associates CC
Project: Environmental Flow Assessment Module:
Geomorphology

Curtis, B.A.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report Country:
Namibia Discipline: Vegetation

Bethune, S.
Environmental Protection and Sustainable Management of the
Okavango River Basin (EPSMO): Transboundary Diagnostic
Analysis: Basin Ecosystems Report

Nakanwe, S.N.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Namibia: Discipline: Aquatic Macro Invertebrates

Paxton,
M. Okavango River Basin Transboundary Diagnostic Analysis:
Environmental Flow Module: Specialist
Report:Country:Namibia: Discipline: Birds (Avifauna)

Roberts, K.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Namibia: Discipline: Wildlife

Waal,
B.V. Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Namibia:Discipline: Fish Life
Country Reports
Angola
Gomes, Joaquim
Análise Técnica dos Aspectos Relacionados com o Potencial
Socioeconomic
Duarte
de Irrigação no Lado Angolano da Bacia Hidrográfica do Rio
Series
Cubango: Relatório Final

Mendelsohn,
.J.
Land use in Kavango: Past, Present and Future

Pereira, Maria João
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Okavango: Módulo do Caudal Ambiental: Relatório do
Especialista: País: Angola: Disciplina: Qualidade da Água

Saraiva, Rute et al.
Diagnóstico Transfronteiriço Bacia do Okavango: Análise
Socioeconómica Angola

Botswana Chimbari, M. and
Okavango River Basin Trans-Boundary Diagnostic Assessment

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Magole, Lapologang
(TDA): Botswana Component: Partial Report: Key Public Health
Issues in the Okavango Basin, Botswana

Magole,
Lapologang
Transboundary Diagnostic Analysis of the Botswana Portion of
the Okavango River Basin: Land Use Planning

Magole, Lapologang
Transboundary Diagnostic Analysis (TDA) of the Botswana p
Portion of the Okavango River Basin: Stakeholder Involvement
in the ODMP and its Relevance to the TDA Process

Masamba,
W.R.
Transboundary Diagnostic Analysis of the Botswana Portion of
the Okavango River Basin: Output 4: Water Supply and
Sanitation

Masamba,W.R.
Transboundary Diagnostic Analysis of the Botswana Portion of
the Okavango River Basin: Irrigation Development

Mbaiwa.J.E. Transboundary Diagnostic Analysis of the Okavango River
Basin: the Status of Tourism Development in the Okavango
Delta: Botswana

Mbaiwa.J.E. &
Assessing the Impact of Climate Change on Tourism Activities
Mmopelwa, G.
and their Economic Benefits in the Okavango Delta

Mmopelwa,
G.
Okavango River Basin Trans-boundary Diagnostic Assessment:
Botswana Component: Output 5: Socio-Economic Profile

Ngwenya, B.N.
Final Report: A Socio-Economic Profile of River Resources and
HIV and AIDS in the Okavango Basin: Botswana

Vanderpost,
C.
Assessment of Existing Social Services and Projected Growth
in the Context of the Transboundary Diagnostic Analysis of the
Botswana Portion of the Okavango River Basin

Namibia
Barnes, J and
Okavango River Basin Technical Diagnostic Analysis:
Wamunyima, D
Environmental Flow Module: Specialist Report:
Country: Namibia: Discipline: Socio-economics

Collin Christian &
Technical Report on Hydro-electric Power Development in the
Associates CC
Namibian Section of the Okavango River Basin

Liebenberg, J.P.
Technical Report on Irrigation Development in the Namibia
Section of the Okavango River Basin

Ortmann, Cynthia L.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module : Specialist Report Country:
Namibia: discipline: Water Quality

Nashipili,
Okavango River Basin Technical Diagnostic Analysis: Specialist
Ndinomwaameni
Report: Country: Namibia: Discipline: Water Supply and
Sanitation

Paxton,
C.
Transboundary Diagnostic Analysis: Specialist Report:
Discipline: Water Quality Requirements For Human Health in
the Okavango River Basin: Country: Namibia

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