Khalid Taiyb Muhammad
Abstract
In Iraqi Kurdistan region, little amount of research has been conducted to evaluate the extent of soil erosion and examine the relation between soil erodibility and other soil indices. Universal soil loss equation (USLE) and Modified Musgrave equation were conducted to predict the amounts of soil that have eroded annually in different zones of Chaqan watershed, which is one of the catchment areas of Darbandikhan Lake in Sulaimani Governorate. Field measurements and laboratory analyses were executed to obtain the parameters of Universal soil loss and Modified Musgrave equations. The results indicated that the amount of annually soil erosion computed by Universal soil loss equation was greater than that obtained by using Modified Musgrave equation. It is evident from the results that the watershed has medium erodibility class (0.1-0.3), and has steep slope, which lead to occurring the great amount of soil erosion. On the basis of gross erosion, the watershed is placed in the severe erosion hazard class (50-200 ton/ha/yr), the possible explanation is its high gradient value. According to this study the watershed can be divided into different zones of the degree of erosion which are geological, very severe, severe, moderate, and light erosion based on the degree of resistant of erosion.