Calculation of soil erosion rate and sediment yield by MPSIACmodel,using GIS(case study: Qurjineh watershed -West of Kabudrahang)

Soil erosion is major global environmental problem. Soil erosion can bea slow process that continues relatively unnoticed or can occur at analarming rate, causing serious loss of top soil. Soil compaction, loworganic matter, loss of soil structure, poor internal drainage, salinizationand soil acidity problems are other serious soil degradation conditionsthat can accelerate the soil erosion process. The main goal of this studyis to predict annual average sediment yield of Qurjineh watershed byempirical model of MPSIAC method, using Geographic InformationSystem (GIS). Qurjineh watershed is located in Hamedan Province(West of Kabudrahang). The area is about 20.03 km2,and 28.29 kmperimeter, with annual precipitation about 340.92 mm. Elevation isranged between 1916.14 to 2389.68 m .This area is a part of geological(1:100000) map of Kabudrahang, and it is one of Forghan's Dam subbasins. The litho unites include: Younger Alluvium Fan, RiverSediment (Quaternary); Phyllit with Quartz Interlayers, Slate, Schist,Chlorite (Jurassic). 9 factors of MPSIAC model were defined by usingArc GIS, after weighting factors utilizing GIS; erosion map is producedaccording to calculated results. The study area is divided to 2 erosionclass: low and very low. And calculated sediment yield of watershed(Qs) 100/78 m3/km2.yr

Keywords:

Erosion , GIS , MPSIAC , Qurjineh , Sediment Yield