Establishing of Soil Loss Tolerance Limit and Sediment Yield in Zagros Fold Thrust Belt: A case study in the Kanarwe river basin, Iraq-Iran

Authors : Fahmy O. Mohammed, Ahmed Ibraheem Mohamed, Ibrahim H. Gart, Diary A Amin

Pages : 76-92

Doi:10.19111/bulletinofmre.1641192

View : 68 | Download : 78

Publication Date : 2025-04-25

Article Type : Research Paper

Abstract :Soil degradation is a significant cause of topsoil loss; in most mountainous region watersheds, it leads to decreased agriculture productivity and reservoir storage. This study targeted calculating and mapping soil loss and sediment yield in the Lesser Zab watershed located between Iraq and Iran. The Revised Universal Soil Loss Equation (RUSLE) model was used to calculate the soil loss. A Digital Elevation Model of 30m, a Digital Soil map (1:500000), rainfall, and land cover were used to derive parameters. The soil loss rates are 58.1 and 0.1 t ha-1yr-1. The total annual soil loss is 1037289 tonnes, of these 404512, covering 75% of Kanarwe river basin land. Most of these affected lands are in the eastern and middle part, which is below the FAOs standard allowable for tolerable soil erosion. Still, the rest covers 25 % of the basin in the west with a total annual soil loss equal to 632777 tonnes, above FAOs standard. The maximum and minimum sediment yield is 29 and 0.1 tha-1yr-1, respectively. Based on the statistical correlation coefficient, the most effective RUSLE Ahmed MOHAMED parameters on sediment yield from high to low are topography 0.48, soil erodibility 0.38, and crop management 0.38.
Keywords : RUSLE, Sediment Delivery, Zagros Thrust Zone, CN-SCS Curve, Dam Lifespan