Determination of Soil Erosion and Sediment Estimation of Khorkhoreh Basin using Sediment Rating Curve

In order to plan and recognize the destructive condition of the watershed, it is indispensable to know the extent of erosion and sedimentation produced from each basin. In this study, the soil erosion and sediment estimation of the Khorkhoreh basin using Sediment Rating Curves were investigated. By integrating geological and geomorphological layers in GIS and removing polygons under 6 ha, 24 working units and 68 sub-basins were attained. To identify the erosion type through field visits, the Bureau of Land Management (BLM) scoring was carried out in each work unit. Using the sediment curve, the amount of total suspended load in the basin was obtained as 2990 ton/yr. With the calculations performed, the amount of specific sediment yield in the Khorkhoreh basin was found to be 25.3 ton/km2. All types of erosion were seen in the portions of the basin, while most of the basin area belongs to the “sensitive” and “very sensitive” to erosion classes. Examination of erosion types showed that in most of the basin’s working units, all types of erosion such as Sheet erosion, Rill erosion, Gully erosion, Channel erosion, and Stream Bank erosion can be observed.