A New Model for Desertification Assessment Using Geographic Information System (GIS) — A Case Study, Runiz Basin, Iran

ABSTRACT The present paper attempts to evolve a new model by considering various indicators of different types of land degradation or desertification, namely, water erosion, soil salinity, vegetation degradation, and lowering of ground water table for finding areas with higher rate of degradation. The Runiz basin, located in the southern Iran, has been selected as a study area to assess the hazard of desertification. The thresholds for the severity classes of indicators were established and then the hazard map for each indicator of types of desertification has been prepared in a GIS. The risk classes of different risk maps were calculated on the basis of classification of risk scores derived by cumulative effect of all the attributes of indicators after overlying them in the GIS. It was possible to distinguish the areas under ‘actual risk’ from areas under ‘potential risk’ of desertification types. Also areas under potential risk were classified to subclasses with different probability level to show a sta...