Objective This study aims to establish a scenario simulation evaluation method for eco-clean small watersheds in water source areas and quantify the erosion and sediment reduction benefits of major measures and their spatial distribution patterns, thereby providing technical reference for the scientific allocation of soil and water conservation measures in small watersheds of water source areas and offering empirical support for the benefit evaluation methods of management projects. Methods The Dabaihe River, a tributary flowing into the Danjiangkou Reservoir area, was selected to evaluate the benefits of comprehensive management of eco-clean small watersheds using the Chinese Soil Loss Equation (CSLE). Model parameters were localized by incorporating measured data from soil and water conservation monitoring experimental stations, enabling a quantitative evaluation of the soil and water conservation benefits of management in the eco-clean small watersheds. Results Before the implementation of management in the Dabaihe River small watershed, the average soil erosion modulus was 1 048.12 t/(km² · a), the total soil loss was 57 028.52 t/a, and the area affected by soil and water loss accounted for 27.10% of the total watershed area. After the implementation of the comprehensive management of eco-clean small watersheds, the average soil erosion modulus and the total soil loss in the watersheds decreased by 26.40% and 28.37%, respectively. Conclusion Stone-bench terraces and earth-bench terraces demonstrate significant effectiveness in reducing erosion and sediment, and closure management measures have a notable impact on controlling soil and water loss in the watersheds. Erosion hotspots are primarily distributed in areas with steeper slopes, which should be prioritized in future soil and water control efforts.
本研究采用中国土壤流失方程CSLE(Chinese Soil Loss Equation)[14]计算土壤水力侵蚀。CSLE模型是根据我国水土流失实际情况,对美国修正通用土壤流失方程USLE进行修订后提出的[15-16]。该模型是我国开展水土流失动态监测的主要方法,也是土壤侵蚀定量评价常用方法之一。CSLE模型包括7个因子的计算,即降雨侵蚀力因子R、土壤可蚀性因子K、坡度因子L和坡长因子S、生物措施因子B、工程措施因子E和耕作措施因子T。中国土壤流失方程基本形式为:
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