基于KINEROS2模型的降雨和坡长因子对土壤侵蚀过程影响的研究

以不同坡长(1,5,10,15,20m)径流小区在不同降雨强度(25,50,75mm/h)下人工模拟降雨试验为基础,通过KINEROS2模型对坡面侵蚀过程及侵蚀量进行模拟,对比分析不同坡长、降雨强度及其交互作用对坡面土壤侵蚀过程及侵蚀量的影响,并评价KINEROS2模型的模拟效果及适用性。结果表明:坡长与总径流量呈一元线性关系(R20.990),与总侵蚀量呈幂函数关系(R20.900);降雨强度与总径流量、总侵蚀量之间呈倍数关系增加,且总侵蚀量的增率是总径流量增率的2~3倍;坡长与降雨强度之间存在交互作用,坡长、降雨强度和降雨强度-坡长交互作用与径流量、侵蚀量呈显著相关关系,并在坡面径流和侵蚀过程中表现为正效应。坡面径流量主要受坡长、降雨强度和降雨强度-坡长交互作用三者综合影响。坡面侵蚀量主要受坡长和降雨强度-坡长交互作用的影响极显著,受降雨强度的影响较显著。KINEROS2模型对径流过程的模拟优于侵蚀过程,对总侵蚀量的模拟优于总径流量,说明KINEROS2模型更适于对径流过程及总侵蚀量的模拟。从总体来看,KINEROS2模型对径流小区坡面土壤侵蚀过程及侵蚀量模拟效果较好,说明KINEROS2模型在中国西北干旱半干旱地区小区尺度上有较好的适用性。

Effects of Rainfall and Slope Length Factors on Soil Erosion Process Based on KINEROS2 Model

In this study,the soil erosion process and erosion amount were simulated by KINEROS2 model according to the artificial simulation test of runoff plots with different slope length (1,5,10,15,20 m) under the different rainfall intensity (25,50,75 mm/h).The effects of different slope length,rainfall intensity and their interactions on soil erosion process and erosion amount were analyzed contrastively,and the simulation results and applicability of the KINEROS2 model were also evaluated.The results showed that the slope length was linear with the total runoff(R2＞0.990),and a power function relationship existed between slope length and total erosion amount (R2 ＞0.900).The total runoff and total amount of erosion increased in multiplies as rainfall intensity increased,and the increasing rate in total amount of erosion was 2 ～ 3 times higher than that of total runoff.There was an interaction between slope length and rainfall intensity,which showed a positive effect on slope runoff and erosion process.The effects of slope length and the interactions of rainfall intensity-slope length on slope erosion amount were more obvious than that of rainfall intensity.The simulation of runoff process and total erosion amount based on KINEROS2 model were better than that of erosion process and total runoff,respectively,indicating that the KINEROS2 model was more suitable for the simulation of runoff process and total erosion amount.Generally,the KINEROS2 model had a better simulation effect on slope soil erosion process and erosion amount of runoff plots,which showed that KINEROS2 model had good applicability in plots scale in arid and semi arid areas,northwest China.