assessment of desertification risk in agricultural land in south of iran

in many countries, studies to determine the severity of desertification and providing land plans to implement desertification. one of the models is modified medalus or iranian model (imdpa), has been used in present research in order to investigate desertification situation in the tashk region of fars province. in this research, the modified imdpa model used with emphasis on the water, soil and agricultural indexes, and indicators for each criterion has been considered in different value. the qualitative values of desertification indexes placed in four classes as, low, moderate sever and very sever. among evaluated indexes, irrigation system and drop level of groundwater have the most effects on desertification with numerical values 4 and 3.7 respectively. in the other indexes, crop yield and sar of water have the lowest effects on regional desertification with numerical value 1 and 1.5 reactively. analysis of result showed that the intensity of desertification obtained 2.54 on the entire of region based on 3 indexes and in the base of modified imdpa model, the regional desertification intensity came to get medium.