内陆绿洲灌溉农田SPAC系统土壤水分动态模拟研究

 基于土壤水动力学原理，建立了内陆河流域山前农田绿洲SPAC系统土壤水分运移的子模型。应用该模型对土壤剖面含水率、农田棵间蒸发和叶面蒸腾量进行了模拟研究，并以实测值进行了验证。对相同种植与田间管理条件下的春小麦生长季田间土壤水分、土壤蒸发和叶面蒸腾量进行了预报，得到了较满意的结果。对模型主要参数土壤饱和导水率Ks、土表排水系数Wmax、净辐射Rn、风速Uz、饱和差D、作物叶面指数LAI进行了敏感性分析，得出这些参数对土壤水分运移的影响显著。应用该模型对西北干旱区内陆河流域山前绿洲灌溉农田的土壤水分均衡和作物根系吸水规律以及SPAC系统中土壤水分运移规律进行了模拟研究。

Simulation of Soil Moisture Content Dynamics in SPAC System of Irrigated Farmland in Inland Oasis, Northwest China

Based on the principle and general momentum equilibrium equation of soil moisture,a realistic model of soil moisture movement in SPAC system is established in this paper.The model is validated with data for evaporation and evapotranspiration obtained in spring wheat field with irrigation in 2003 and 2004.The results show that the model is capable of simulating soil water dynamical movement.Meanwhile,the sensitivity analysis of the soil saturated conductivity K_(s),drainage modulus W_(max),net radiation R_(n),wind speed U_(z),vapour pressure deficit D and leaf area index(LAI) to soil moisture content,from which the results show that the variation of these parameters dynamic impact dramatically on the dynamic of soil moisture movement.Furthermore,the model system has been used for simulating the water balance in field planted spring wheat under the condition of irrigation at fore-mountain oasis belts in drought area of northwest China,and water uptake by roots and soil moisture movement in SPAC system.