Green-Ampt模型入渗率显式近似解研究

Approximate Explicit Solution to Infiltration Rate of Green-Ampt Infiltration Formula

Green-Ampt入渗模型应用广泛,是模拟坡面降雨入渗、产流过程常用的手段,但模型中入渗率i(t)与时间t呈隐式关系为实际应用带来困难。根据对土壤宏观毛管长度λ。与Green-Ampt入渗模型参数S_f的分析,建立了Green-Ampt入渗模型参数与Philip公式参数的关系,并得到了入渗率i的显式近似解。实测资料和近似解的计算值进行对比结果表明,显式近似解具有较高的预测精度,其入渗过程中入渗率整体相时误差仅为0．04％。图4．表1,参17。

Green-Ampt infiltration model, which is the normal method to simulate rainfall infiltration and runoff generating procedure in slope, is used widely. But it is usually not very convenient in practical use, because in the model, infiltration rate （i（t）） is expressed in implicit formula, their values can not L,e gained directly from temporal ordered data. In this paper, according to the analysis of soil macro-capillary length （λc） and parameter Sf of Green-Avapt infiltration model, the relationship between Green-Ampt model parameters and Philip＇s formula parameters was established, and approximate explicit solution to Green-Ampt infiltration rate based on Philip＇s formula wars also achieved. The results of comparison of measuring values and calculated values with the approximate solution showed that predicting accuracy wars very satisfied, its integral relative error was only 0.04%.