Usman Kelil, Deribew Kiros Tsegay, Alemu Girma, Hailu Samuel
Limu-Seqa District Bureau of Agriculture and Natural Resource, Jimma Zone, P.O. Box 192, Jimma, Ethiopia.
Department of Geography and Environmental Studies, Raya University, P.O. Box 92, Maichew, Ethiopia.
Heliyon. 2023 Mar 13;9(3):e14590. doi: 10.1016/j.heliyon.2023.e14590. eCollection 2023 Mar.
Soil erosion is a vector of disturbances to agricultural productivity and economic development in the western highlands of Ethiopia. Yet, tough vegetation cover loss swapped to other land uses could have amplified the soil loss rate at which land cover change preceded, but little is known about their effects on soil loss in the Limu-Seqa watershed. This study was designed to evaluate the historical trends of the effects of land use-land cover change on soil erosion dynamics as a threshold for potential monitoring of soil loss. Satellite image data of 1987, 2002, 2021, and DEM-20 m resolution were used. The RUSLE model was applied with primary parameters to generate soil loss. Findings show that average annual soil loss increased from 4.5 in 1987 to 13.5 t ha yr in 2002 and surpassed to 45.35 t ha yr in 2021 as a result of LULC changes, particularly the transition of forest and overgrazed land to cropland (43.83%) and dense-forest to poor-open-up forest (6.92%) between 1987 and 2021. Soil loss during the recent study period was substantially affected by a substantial LULC change, from forest to cropland. The severe and very severe erosion risk categories jointly cover more than half of the entire catchment, which contributes to two-thirds of the total mean annual soil loss in the watershed, which is found to be over and above soil loss tolerance (SLT) in Ethiopia and tropical regions. Therefore, given the robust economic and political status of priority conservation measures, red hues areas are significant.
土壤侵蚀是埃塞俄比亚西部高地农业生产力和经济发展受到干扰的一个因素。然而,尽管植被覆盖丧失转而用于其他土地用途可能会加剧之前土地覆盖变化时的土壤流失速率,但关于其对利穆-塞卡流域土壤流失的影响却知之甚少。本研究旨在评估土地利用-土地覆盖变化对土壤侵蚀动态影响的历史趋势,作为潜在土壤流失监测的一个阈值。使用了1987年、2002年、2021年的卫星图像数据以及分辨率为20米的数字高程模型(DEM)。应用RUSLE模型及主要参数来生成土壤流失量。研究结果表明,由于土地利用/土地覆盖变化,特别是1987年至2021年间森林和过度放牧土地向农田的转变(43.83%)以及茂密森林向稀疏森林的转变(6.92%),年均土壤流失量从1987年的4.5吨/公顷·年增加到2002年的13.5吨/公顷·年,并在2021年超过至45.35吨/公顷·年。在最近的研究期间,土壤流失受到土地利用/土地覆盖从森林向农田的重大变化的显著影响。严重和极严重侵蚀风险类别共同覆盖了整个集水区的一半以上,这导致了该流域年均土壤流失总量的三分之二,这一数值超过了埃塞俄比亚和热带地区的土壤流失容忍度(SLT)。因此,鉴于优先保护措施强大的经济和政治地位,红色区域意义重大。