基于改进降水输入模块的农田地表中尺度径流模拟

Simulation of mesoscale runoff on farmland surface based on improved precipitation input module

针对传统方法对农田地表中尺度径流模拟结果不准确的问题,提出基于改进降水输入模块的农田地表中尺度径流模拟方法。设置土壤、农作物、气象、汇流输入、区域控制等文件构建VIC水文模型数据,确定模型率定参数后利用相对误差和纳什效率系数评估参数率定效果;构建包括农田降水排水及其污染物浓度预测功能的农田污染"源"模块,考虑农田地表径流中各项污染物浓度;基于地表与地下水的耦合作用求取土壤蓄水量,结合实际土壤入渗率计算农田的地表径流量。为了验证本文方法的准率性,以黄河流域农田为研究区,根据上述参数对农田地表径流进行计算。结果表明,本文方法能够准确模拟农田地表径流,年尺度与月尺度的地表径流量模拟值和实测值基本吻合,具有较高的实用价值。

Aiming at the inaccuracy of the traditional method for the simulation of mesoscale runoff in farmland surface,a mesoscale runoff simulation method based on improved precipitation input module is proposed.Set up soil,crop,meteorology,confluence input,regional control and other documents to construct VIC hydrological model data,determine the model′s rate parameters,and use the relative error and Nash efficiency coefficient to evaluate the parameter rate effect.Construct a"source"module of farmland pollution including farmland precipitation drainage and its pollutant concentration prediction function,and consider the concentration of various pollutants in farmland surface runoff.Calculate the amount of soil water storage based on the coupling effect between surface and groundwater,and calculate the surface runoff of farmland based on the actual soil infiltration rate.In order to verify the quasi-rate of the method,the farmland in the Yellow River Basin was used as the study area,and the surface runoff of farmland was calculated according to the above parameters.The results show that the method can accurately simulate the surface runoff of farmland,and the simulated and measured values of surface runoff at annual scale and monthly scale are basically consistent with the measured values,which has high practical value.