陕北黄土沟壑区降雨入渗产流产沙模型与应用

Runoff and Sediment Yield Model and Its Application in Loess Plateau Region of Northern Shaanxi Province

在陕北黄土坡地枣园人工降雨产流产沙试验基础上,结合Philip入渗模型、坡面运动波模型和通用土壤流失方程,建立基于雨强、径流深、坡长、坡度和植被覆盖度等因素的次降雨产流产沙模拟模型,并通过人工降雨产流产沙试验验证模型。结果表明,径流量实测值与模拟值的NSC为0.87,平均误差为15%;产沙量实测值和模拟值的NSC为0.77,平均误差为26.2%。产流过程的模拟误差多在10%以下。坡面糙率随坡长的增大而呈减小趋势;随坡度的增大,单宽流量对坡度的响应敏感性逐渐减小。建立的次降雨产流产沙模型可以很好地模拟产流、产沙总量以及动态产流过程。

The runoff and sediment yield model was established on the basis of Philip infiltration model, kinematic wave overland flow equation and universal soil erosion prediction model, which considered the rainfall intensity, runoff depth, slope length and vegetation cover. The established model was verified through the artificial rainfall runoff and sediment simulation experiments in jujube orchards on the Loess Plateau of Northern Shaanxi province. The results indicated that NSC was 0.87 and the average error was 15% between the measured data and simulated data of runoff, while NSC was 0.77 and the average error was 26.2% between the measured data and simulated data of sediment yield. The error was below 10% for the simulation of sediment process on the whole. Roughness coefficient decreased with the increase of slope length. With the increase of slope, the response sensitivity of single wide flow on the slope decreased. Runoff, total runoff and total sediment yield and dynamic process could be simulated well using the established runoff and sediment yield model.