METHOD
•   The soil attributes and the corresponding weights used for calculating the vulnerability index for pollution by runoff (surface waters) are:
•Dominant limitation to agricultural use. If the codes for this attribute are: “Eroded phase, erosion”, “Lithic (coherent and hard rock within 50 cm)” or “Petrocalcic (cemented or indurated calcic horizon within 100 cm)” then the weight is ”1”.
•Secondary limitation to agricultural use. If the codes for this attribute are: “Eroded phase, erosion”, “Lithic (coherent and hard rock within 50 cm)” or “Petrocalcic (cemented or indurated calcic horizon within 100 cm)” then the weight is  “0.5”