基于UAV数据的黄河中游多沙粗沙区小流域水土保持措施空间优化配置及减沙潜力研究OA

[Objective]This study aims to investigate the soil erosion conditions in small watersheds of rich and coarse sediment area in the middle reaches of the Yellow River using high-precision data,and to propose a spatial optimization scheme for soil and water conservation measures,providing theoretical references for the comprehensive management of small watersheds.[Methods]Three typical small watersheds(Hailesitaigou,Liudaogou,and Yangjiagou)in the rich and coarse sediment area of the middle reaches of the Yellow River were selected as the study area.Based on 2023 UAV orthophotos,multispectral data,DSM data,and field soil sampling data of the small watersheds,the Revised Universal Soil Loss Equation(RUSLE)model,optimal parameters-based geodetector,and GIS techniques were used to analyze the spatial variation characteristics of soil erosion and its key driving factors in the three small watersheds.Schemes for the improvement of fractional vegetation cover(FVC)by 10%～35%within a sustainable threshold(<65%)and for the spatial optimization of terraces and check dams were proposed.Subsequently,sediment reduction potential under scenarios of single and multiple soil and water conservation measures was evaluated.[Results](1)In 2023,soil erosion in the three small watersheds was predominantly very slight and slight erosion,while the proportion of areas with intense or higher erosion reached 11.69%～15.65%.The soil and water conservation rate ranged from 45.83%to 65.32%.(2)Slope,land use,and FVC were the dominant drivers of the spatial variation of soil erosion,and the nonlinear enhancement effect of the interaction between slope and land use was the most significant.(3)The soil and water conservation measures in the small watersheds ranked in terms of sediment reduction benefits as follows:FVC increase+terraces+check dams>FVC increase+terraces>FVC increase+check dams>FVC increase>single engineering measures.When FVC was increased by 35%within the sustainable threshold,the sediment reduction potential of the three small watersheds was 23.74%～30.97%.Under the scenario of 35%FVC increase+terraces+check dams,the sediment reduction potential in the three small watersheds was 26.37%～35.71%.[Conclusion]UAV data significantly enhance the accuracy of soil erosion intensity identification and the spatial optimization of soil and water conservation measures.The valley slopes and bare land areas in the three small watersheds are the key areas for erosion control.The optimization of multiple measures in the watersheds demonstrates significant sediment reduction effects,but vegetation restoration should be taken as the core,with engineering measures serving as a supplement.