喷灌条件下的土壤水分二维入渗数值模拟研究

Numerical simulation of soil moisture distribution under sprinkler irrigation condition

根据喷灌的入渗特性,以二维土壤水分基本运动方程为基础,建立二维入渗土壤水分运动的数学模型,并用SWMS—2D软件进行模拟计算。根据田间试验对模拟结果进行分析验证,模拟值与实测值比较符合,误差较小。结果表明:所建模型合理,可以用所建模型来模拟、预测不同灌水因素组合情况下的土壤水分分布特性;土壤质地结构对土壤水分分布模式影响较小,灌水历时和土壤初始含水率对土壤水分分布模式影响较大;灌水历时对根系层体积含水率影响不大,但土壤质地和土壤初始含水率对根系层体积含水率影响较大。

Based on the infiltrating character of sprinkling irrigation and the theory of water movement in unsaturated soil,a mathematical model for two-dimensional infiltration was developed to describe soil water movement and the software SWMS—2D was to solve this model.Using field experiment to analyze and verify the simulation results,it showed that the simulation values were in a good agreement with the measured values,so that the model is reasonable.The soil moisture distribution characters in the case of definite combination of different irrigation elements were simulated numerically with this model and method.The soil texture structure had a slight influence on the soil moisture distribution pattern,while single irrigation duration,initial water content had a larger impact on the soil moisture distribution pattern.The soil texture structure and initial water content had a greater influence on the volume moisture content of the root system,while single irrigation duration had a smaller influence on the moisture content.