Soil Erosion Risk Assessment Using Revised Universal Soil Loss Equation RUSLE Model: a Case Study in Shwan Sub basin, Kirkuk, Iraq

The revised universal soil loss equation (RUSLE) was used in order to predict the amounts of soil lost by water erosion in the study area. The equation depends mainly on the factors that affect soil erosion represented by soil characteristics, rain fall, topography, vegetation cover, and conservation factor. The study showed that the study area was divided into three classes according to the degree of severity. The class1, the low risk of soil erosion, concentrated in all western parts and some central parts of the study area, occupying an area of 42525.61 hectares, at a rate of 41% of the total area. The class 2, a moderate risk of soil erosion, occupied an area estimated at (40451.19) hectares (39%), spread in the northern, northeastern, some central and southern parts of the study area, while the class 3, the high risk of erosion, had an area of 20744.20 hectares (20% of the area of the region), concentrated in the eastern and southeastern parts of the study area. Generally, the total amounts of soil lost annually due to water erosion in the study area amounted to 1,570,748 tons. The results also showed that the RUSLE model of soil water erosion risk mapping is a highly effective and cost-effective approach.