非饱和带土壤水联系了地表水和地下水，是影响地表水径流、地下水蒸发、补给和地下水污染的关键环节。充分了解区域非饱和带水分运动特征和规律，对地下水资源评价和地下水污染防护具有重要的理论意义和应用价值。本研究根据区域尺度非饱和土壤空间变异的随机分布特征，对局部尺度土壤水分运动方程和相应的水分运动参数进行尺度提升，建立以宏观土壤含水量为系统状态变量的区域土壤水分运动方程，提出确定土壤宏观水力参数的方法，研发宏观非饱和土壤水分运动与区域地下水运动的耦合模型。开展野外实验，探讨非饱和带岩性、根系吸水、降雨、蒸发等因素对区域土壤水分和地下水运动的影响，检验耦合模型的实用性，探讨地下水补给量对各种随机因素的响应规律。

The unsaturated zone connectes surface water and groundwater, which dominates the runnoff, evaporation, recharge and groundwater pollusion in regional scale. Understanding the regim and characterisctics of water flow and solute transport in unsaturated soils is very important for the evaluation of groundwater resource and contamination protection. The macroscopic soil water movement equation with the mean water content as a state variable in regional scale will be studied by using the stochastic upscaling method based on the spatial variability of soil hydraulic parameters at local scale. The structure of the macroscopic hydraulic parameters in regional scale will be obtained from the upscaling equaton, and the determination method of the macroscopc parameters will be studied. We will develop a numericall method which combines the upscaling unsaturated water flow equation with the regional groundwater flow equation. A field experiment is designed to study the affect of unsaturated soil hydraulic parameters, root uptake, rainfall and evaporation on the mean soil water distribution and groundwater movement in regional scale, and to examine reliability of the upscaling equation, macro-hydraulic parameters, and the conbined numerical model. The model will be used for the analisys of groundwater recharge.