Assessment of desertification intensity using IMDPA method (Case study: Dashte Abbas, Ilam)

The aim of this study was assessed desertification potential of the Dashte Abbas in the semiarid region of Ilam provience18028.8 hectares by using the Iranian model of desertification potential assessment (IMDPA) on soil and vegetation cover indicators. The geometric average for each index including effective soil depth, soil texture, electrical conductivity of soil, percent of gravel, the operation of the plant, the revitalization of vegetation and vegetation condition was obtained using ArcGIS®9.3 and the status map of each criteria was prepared. Finally, by combining and determination of geometric mean desertification intensity map was obtained. The desertification intensity map based on soil criteria demonstrated that over 4843 hectares (28.86% of the total area) and 13185 hectares (73.13% of the total area) has been taken in low and moderate classes, respectively. Also the obtained results from geometric average of vegetation cover criteria indices showed that 7005.99 hectares (38.86% of the total area) in the lower classes and 407.45 hectares (2.26% of the total area) and 10615.35 hectares (58.88% of the total area) has been taken in moderation and Severe classes, respectively. The results of the assessment the considered Catteries indicating that vegetation cover criteria with values of 2.6 is the most influential criteria in the severity of desertification in the study area. Accordingly, it can be said that the quantitative value of the desertification intensity of the total area has been taken in moderate class.