Study of desertification status using IMDPA model with emphasis on water and soil criteria (Case study: Khezr Abad - Elah Abad of Yazd - plain)

More than 80% of Iran’s area has arid and semi arid climate. Therefore، Iran is exposed to desertification process. Practical activities in controlling desertification must be based on current desertification situation and its severity. Based on this theory، evaluating desertification rate indices in Khezrabad region was done based on IMDPA model. In this research two factors with 10 indices were investigated. Each of the investigated indices was analyzed and scored based on work units. Data layers of each index were made by Arc GIS software. By compiling data layers and calculating geometric mean of indices، desertification rate map of the region was then prepared. According to the selected indices، final desertification map shows the mean rate of desertification. Soil index by 2. 21 scoring value was classified in median class while water index by 1. 46 scoring value was classified in poor class. Soil depth had the biggest influence while SAR and Cl of water had the least influence on desertification. Based on the assessments، geometrical mean of desertification rate quantity value for the entire region was 1. 76، thus the entire region was classified in median class.