Desertification Evaluation Using IMDPA Model (Case Study: Taraz Nahid, Saveh, Iran)

Abstract. Several studies have been performed to evaluate the desertification in Iran and other countries which led to present national and regional models. One of them is IMDPA model. This model was used as a case study in Taraz Nahid, Saveh, Iran. In this study, five factors including climate, soil, vegetation, irrigation, and socioeconomic ones were evaluated. According to the region conditions for each criterion, several indices were considered. Based on the selected indices for each criterion, the qualitative maps were developed from geometric mean of indices for each criterion and finally, the desertification intensity map was prepared from the geometric mean. The final desertification map shows the balanced (moderate) and intense (severe) classes of desertification process in the region. According to the performed evaluations, the soil texture index with the average value of 3.75 (very severe class) and vegetation conditions with the average value of 2.9 were more effective indices in the region desertification. Also, the desertification quantitative intensity value (DM=2.31) was calculated for the entire study region that showed the moderate class for this region.