坡形对坡面侵蚀过程的影响机制研究  

Research on the Effects of the Slope Shape on the Soil Erosion Process on the Sloping Surface

作　　者：隗晓琪 吴松柏 WEI Xiao-qi;WU Song-bai(College of Urban and Environmental Sciences,Northwest University,Xiʹan 710127,Shaanxi Province,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]西北大学城市与环境学院,陕西西安710127 [2]中国科学院大学,北京100049

出　　处：《中国农村水利水电》2023年第7期117-123,共7页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(42007056)。

摘　　要：采用实地观测和模拟降雨试验方法分析坡形对坡面侵蚀过程的影响机制,易受到客观环境条件的限制,难以全面分析不同因素对坡形效应的影响。研究基于被广泛检验过的WEPP模型,设置4种常见的坡面形状,分别为直线型、凸型、凹型和S型,研究不同坡形对土壤侵蚀过程的影响机制,并在此基础上分析坡形效应对不同降雨、土壤和细沟参数的敏感性。结果表明,不同坡形会显著改变坡面土壤侵蚀强度及其空间分布。随着降雨强度的增加,四种坡形的总侵蚀量和空间差异均会增加,其中凸型坡面总侵蚀量增加幅度最大,约为凹型坡增幅的2倍。随着细沟间距与初始细沟宽度比值的增加,所有坡面上的土壤侵蚀强度均有所减小,空间差异性也有所减小,其中S型坡面的土壤侵蚀强度整体减小程度最大,直线型坡面整体减小幅度最小。随着细沟可蚀性系数的增大,4种坡形的侵蚀区和沉积区相应的土壤侵蚀量和沉积量均有增加,但其增幅存在较大的空间差异性,相对而言,凸型坡面和S型坡面空间差异性变化较凹型和直线型坡面大。而随着细沟间可蚀性参数的增大,四种坡形坡面土壤侵蚀量及其空间分布变化并不明显。上述研究结果有助于深化坡面土壤侵蚀理论,对黄土高原不同坡形坡耕地土壤侵蚀防治和高质量发展具有重要的实践意义。Field and laboratory experiments are usually used to reveal the impacts of the slope shape on the soil erosion process,but the fixed experimental conditions are restrained in analyzing the impacts of other related factors on the slope shape effect.Based on the widely used WEPP model,the soil erosion processes are simulated and compared for four common slope shapes in nature,including linear,convex,concave,and S-shaped.The sensitivities of slope shape effect to different rainfall intensity,soil erodibility,and rill density parameters are also analyzed.The results show that soil erosion and its spatial distribution can be significantly changed for different shaped slopes.With the increase in rainfall intensity,both the total erosion and its spatial difference tend to increase greatly for four shaped slopes.The increase in total erosion for the convex slope is more significant,which is about two times as large as that of the concave slope.As the ratio of rill spacing to initial rill width increases,the soil erosion intensity and its spatial difference decrease on all slopes.The decrease in soil erosion intensity is more significant on S-shaped slope but less significant on linear slope.With the increase in rill erodibility parameter,the soil erosion density and its spatial difference increase on four slopes.The spatial difference on convex and S-shaped slopes changes greatly in comparison with those on linear and concave slopes.However,the soil erosion density and its spatial difference are not sensitive to the interrill erodibility parameter for all slopes.The above results are helpful to deepening the theory of soil erosion on different shaped sloping surfaces,which are expected to be useful for soil erosion prevention and high-quality development of sloping farmland on Loess Plateau.

关 键 词：WEPP 土壤侵蚀 坡形 模型 细沟 

分 类 号：S157.9[农业科学—土壤学]