Abstract

Soil erosion and the subsequent sedimentation are the major problem in Ethiopia. We assessed the impact of rainfall-induced soil erosion and prioritize the sub-watersheds using RUSLE and SYI models. We procured mean annual precipitation, Abay Basin soil map, Digital Elevation Model (DEM) and LANDSAT 8 OLI/TIRS, 2017 datasets. Results show that annual estimated soil loss was ≤270 and ≤120 t ha⁻¹ yr⁻¹ whereas, mean rates were 37.72 and 23.92 t ha⁻¹ yr⁻¹ for RUSLE and SYI models respectively. Both the models have identified ∼25% area of sub-watersheds (SW19 to SW23) has similar average soil loss (>20 t ha⁻¹ yr⁻¹) at higher elevations. Interestingly, similar erosion severity, priority level and ranks were observed through RUSLE and SYI. Findings indicate a strong relationship between erosion rate and topography. The severe erosion prone area requires immediate action for conservation treatment proposed in study.

摘要

土壤侵蚀和随后的沉积是埃塞俄比亚的主要问题。我们评估了降雨引起的土壤侵蚀的影响，并使用 RUSLE 和 SYI 模型对子流域进行了优先排序。我们采购了年平均降水量、阿拜盆地土壤图、数字高程模型 (DEM) 和 LANDSAT 8 OLI/TIRS, 2017 数据集。结果表明，年估计土壤流失量为≤270 和≤120 t ha ^-1  yr ^-1，而 RUSLE 和 SYI 模型的平均速率分别为 37.72 和 23.92 t ha ^-1  yr ^-1。两种模型都确定了约 25% 的子流域面积（SW19 至 SW23）具有相似的平均土壤流失量（>20 t ha ^-1  yr ^-1) 在更高的海拔。有趣的是，通过 RUSLE 和 SYI 观察到类似的侵蚀严重程度、优先级和等级。研究结果表明侵蚀率和地形之间有很强的关系。严重侵蚀易发区域需要立即采取研究中提出的保护处理措施。