土壤含水量对陆一气相互作用过程中的能一水平衡计算以及降雨、农业灌溉对地下水补给的研究起着关键的作用。但现阶段大多数陆面过程模式对土壤含水量的计算采用一维水桶模式，忽略了流域尺度上的侧向补给、地下水位的变化、包气带土壤的非线性渗透特性对土壤含水量的影响。针对这一问题，在国内外研究较为成熟的饱和一非饱和理论的基础上，编程实现了包气带土壤水分传输方程的求解，并与陆面过程模式（SIB2）相耦合，建立起研究分层包气带土壤水分运移、非稳态的地下水位、和地表蒸散发之间定量关系的模型。最后，利用建立的耦合模型，以河西走廊黑河流域中游临泽农业综合观测场的灌溉试验为例，模拟干旱内陆平原区小麦生长期间定额灌水条件下土壤含水量的变化。计算结果表明：模型能够准确计算瞬时土壤含水量、非稳态的地下水位，并对小麦生长过程中的耗水量进行估算，进而为农业合理灌溉提供了科学的理论基础。

The soil moisture content plays the vital role in the interaction of land-gas and balance of energywater of surface land. However, in recently, the one dimensional bucket pattern is used as many land surface process models to compute the soil moisture content, which neglects the problems that the lateral supplies, the groundwater level and the penetration coefficient are function to saturation. Therefore, this article, based on the saturated - unsaturated theory which is domestic and mature over world, proposed simulation method of coupling the package of soil moisture transmission model and the land surface process pattern, and expressed dynamically the soil moisture migration process and change of groundwater level change under unstable state. Using the established coupling model, taking the Hexi corridor-Heihe basin middle reaches as the example, this article also simulated changes on the soil moisture content and the groundwater level under condition of different irrigating during wheat growth period in arid inland region, the results indicated the model established in this article was allowed to calcu- late changes of the instant soil moisture content and the groundwater level, and estimate the water consumption during the wheat growth period, then provide an rational academic basement for the reasonable agricultural irrigation.