基于水蚀预测模型的红壤坡面侵蚀主要影响因素研究

Major Factors Affecting Erosion and Runoff on Red Soil Slope Based on WEPP Model

利用229场侵蚀性自然降雨的小区观测数据,率定并验证了典型红壤坡面水蚀预测(WEPP)模型,并对模型的敏感性检验和弹性系数进行了分析。结果表明,红壤坡面土壤侵蚀对降雨量、雨强、细沟可蚀性、临界剪切力、坡长、坡度等6个输入参数的变化具有强敏感性;地表径流量对降雨量具有强敏感性,对雨强、初始饱和导水率、有效水力传导系数等参数存在弱敏感性。这些参数是影响红壤坡面侵蚀产沙产流的主要因素。

A data set,which includes soil losses from field standard runoff plots established in red soil region during 229 rainfall events,was used to calibrate and validate the physically based soil erosion model（water erosion project,WEPP model）.Meanwhile,sensitivity test and elastic coefficient analysis methods were applied to determine the major influencing factors of soil erosion and runoff on red soil slopelands.The results showed that erosion sediment yield is extremely sensitive to the input parameters including rainfall amount,intensity,rill erosion threshold,critical shear stress,slope length and gradient.Surface runoff is regulated strongly by the rainfall amounts,while is weakly sensitive to rainfall intensity,initial saturated hydraulic conductivity and effective hydraulic conductivity.In conclusion,all parameters aforementioned are the major controlling factors of soil erosion and runoff on red soil slopelands.