基于数值方法的农田土壤零通量面的模拟  

Simulation of Zero Flux Plane of Farmland Soil Based on Numerical Method

作　　者：王佩浩 张茜[1] 张吴平[1] WANG Pei-hao;ZHANG Qian;ZHANG Wu-ping(Shanxi Agricultural University, Jinzhong 030801, PRC)

机构地区：[1]山西农业大学,山西晋中030801

出　　处：《湖南农业科学》2019年第3期80-84,共5页Hunan Agricultural Sciences

基　　金：山西省重点研发计划重点项目(201703D211002-2);山西省科技攻关项目(20130311008-5)

摘　　要：零通量面能够反映土壤水分运动情况,定量计算土壤水分的入渗和蒸散量。采用Richards方程描述了降雨和蒸发边界条件下的一维土壤水分运移,通过土壤传递函数估算得到Van-Genuchten水分特征曲线参数,借助参数化Hydrus-1D模型计算得到一维土壤空间不同层的土壤含水量和基质势的数值解,并采用田间实测数据对数值解进行了验证,根据不同层的水势梯度和水流通量的值判断零通量面出现位置以及零通量面类型,最后分别设置5个不同的降雨和蒸发强度,模拟分析了土壤零通量面的空间位置和类型。研究结果表明:(1)采用Hydrus-1D可以准确模拟降雨和蒸发条件下的一维土壤水分运移;(2)在降雨和入渗条件下,零通量面位置随之降低;(3)蒸发强度增加时,零通量面上部土水势降低,土壤吸力增大,使其位置上升。结果证明该方法可行,能够模拟零通量面的动态变化。The zero flux plane can reflect the soil water movement and calculate the infiltration and evapotranspiration of soil moisture quantitatively. In this study, the one-dimensional soil water transport under rainfall and evaporation boundary conditions was described by Richards equation, and the Van-Genuchten water characteristic curve parameters were estimated by soil transfer function. The numerical solution of soil water content and matrix potential in different layers of one-dimensional soil space was calculated by means of parametric Hydrus-1D model, and the numerical solution was verified by field measured data;according to the water potential gradient and water flow value of different layers, the position and the type of the zero flux plane were judged. Finally, five different rainfall and evaporation intensities were set, and the spatial position of the zero flux surface of the soil was simulated and analyzed. The results showed that:(1) Hydrus-1D could accurately simulate one-dimensional soil water transport under rainfall and evaporation conditions;(2) Under the condition of rainfall and infiltration, the position of zero flux surface declined;(3) In response to evaporation intensity increasing, the soil water potential on the zero flux plane reduced, and the soil suction increased, so the position of zero flux surface rised. This method was improved feasible and could simulate the dynamic changes of the zero flux plane.

关 键 词：零通量面 土壤水势 土壤含水量 数值模拟 

分 类 号：S152.7[农业科学—土壤学]