层状土壤中一维非饱和土壤水分运动的随机模拟

在田块尺度条件下的层状土壤中，土壤水力特性及土壤水分变量在空间上的分布可以看作是一维随机空间函数的实现。利用AR（1），MVAR（1）和NNM等3种随机生成模型分别生成饱和水力传导度、孔隙大小分布参数和容水度的随机样本，在此基础上利用随机模拟法对一维非饱和土壤水分运动进行了随机模拟。结果表明：不同的土壤参数的空间变异对非饱和土壤水分运动的影响是不同的，土壤参数的方差越大，对非饱和土壤水分运动的影响越大；土壤参数的空间变异尺度越大，对非饱和土壤水分运动的影响越大；随机模拟计算所得的水分变量的一阶矩与大尺度模型计算结果甚相一致。

Stochastic Analysis of One-dimensional Unsaturated Flow in a Stratified Soil

The spatial distributions of soil hydraulic properties and soil water Variables in a stratified soil are described as random space functions,and three types of models of AR(1),MVAR (1),and NNM are adopted to generate realizations for saturated hydraulic conductivity, poresize distribution parameter and soilwater capacity. The influerices of the spatial variability of soil parameters on oneLdimensional unsaturated flow in a stratified soil are synthetically analyzed with Monte Carlo simulation. The results indicated that the influences of spatial variability of different soil parameters on unsaturated flow are different each other. The first order moments of soil water variables aTe in consistance with those calculated by largescale unsaturated flow model.