Soil Erosion in Al-Adhaim River Basin, Central Part of Iraq

Al-Adhaim River is one of the main tributaries of the Tigris River, it has three main tributaries: Khassa Soo, Aq Soo, and Tuz Chia, all of which are seasonal streams. The course of Al-Adhaim River and its three tributaries flow in a very rugged topography, especially in the upper courses with high gradients. The exposed rocks in the catchment area are mainly soft claystone rocks with coarse conglomerate and sandstone, which are very easily eroded by the running water, especially during floods. We have used SRTM images of ground resolution of 3-arc-second (90 m) and a vertical resolution of approximately 10 m to divide the catchment area into 14 sub-basins using ArcGIS (Arc map). Moreover, many factors concerning soil erosion were calculated, such as drainage density, erosion intensity, erosion rates, and soil erodibility. We have found that the drainage density ranges between (0.26 - 0.39) km/km2 with class Poor, the Erosion Intensity ranges between (264 - 387) m/km2 with Very poor zone, the Erosion rates (Kk) ranges from (0.01 - 0.325), and the Erosion Coefficient ranges from (0.7 - 1.0).