用非饱和土壤物理参数模拟坡面产流过程研究

Runoff Processes Simulation on Land Based on Unsaturated Soil Physical Properties

采用人工模拟降雨方法 ,在用蒸发法测定非饱和土壤物理参数和基础上 ,运用修正的Green -Ampt入渗模型 ,结合退水曲线法和坡面运动波模型 ,研究了 9场不同雨强和不同历时模拟降雨的产流过程。结果表明模拟误差在11 0 %～ 30 7%间变化 ,80 %的模拟误差可控制在 18%以内 。

Runoff processes simulation is very significant for soil erosion mechanism analyzing and erosion model building.In the past two decades,many runoff simulation model were built in China based on different conditions,however,they were difficult to qpply widely.Therefore,building one new model is necessary.In order to find one easy and exact way to simulate runoff process on slope land,9 simulated rainfall experiments were carried out on one plot with 10mlength,2m width and 15 degree at Ansai field station.Soil physical properties are the basic information to influence soil infiltration and runoff appeating.So soil physical properties were measured using 2 soil samples taking from polt for dach rainfall event by means of STAR-1 and unsaturated soil arameters, which was analyses by Appia program, were obtained.Those parameters were used to calculate soil absorptive parameter S f.And then,the modified Green &Ampt infiltration model,Retention Curve method and kinematic wave model were used to simulate runoff processes.The results indicate that using unsaturated soil physical properties to simulate runoff processes are available and the relative errors vary from 11.0 to 30.7%,However, more 80% simulated drror are less than 18 percent and it demonstrates using unsaturated soil physical properties to predict runoff process is reasonable and should be used widely.