Comparison of erosion and sediment yield estimation in Sezar sub-basin (Dez drainage basin) by MPSIAC and EPM empirical methods, using GIS

Sezar sub-Basin is a part of the Dez-dam catchments area (Zagros Zone, Lorestan Province), with an area of 3370 Km2 and 267 Km periphery length. In this study, erosion potential and sediment- yield of the basin was estimated by EPM and MPSIAC methods using GIS data. The values of the main parameters in the MPSIAC and EPM models in the sub basin were evaluated in a GIS environment. Then, the potential and annual sediment yields were calculated by combination of the main parameters in EPM and MPSIAC methods. In both methods, 80% of the study area is in the high- and very high – erosion potential classes, which are located in southwestern part of the area, where Pabdeh, Gurpi and Gachsaran formations are present. At the next step, clustering erosion in potential and sediment yield of the basin were estimated by fuzzy and clustering methods. The annual sediment in MPSIAC and EPM models were 2985584 and 5205725 m3, respectively. The results of clustering method show the class boundaries in the basin are transitional. Also comparison of three methods show an over-estimation tendency, however, MPSIAC results are more reliable.