地下水模型MODFLOW和GIS在华北平原地下水资源评价中的应用

从MODFLOW源程序的角度出发,根据地下水模型计算需要的输入输出数据格式和我国GIS类数据以MAPGIS为主的特点,建立了二者之间的集成关系,并将其应用于华北平原地下水资源评价中。根据华北平原特定的水文地质条件,建立了适合本区的三维非稳定流地下水模型,结合2003年12月的实际流场以及随时间变化的动态观测资料对模型的渗透系数、给水度和释水系数等参数进行了校正。同时进行了水均衡分析,结果表明华北平原地下水在2002年1月至2003年12月总补给量为493.74×10⁸m³,总排泄量为565.30×10⁸m³,均衡差为-71.56×10⁸m³,为负均衡。集成了该地下水模型的信息系统,可以通过更新源汇项数据库资料而对地下水资源进行实时评价,为华北平原水资源可持续利用和管理提供依据。

The application of groundwater model, MODFLOW, and GIS technology in the dynamic evaluation of groundwater resource in North China Plain

Nowadays the water resources shortage and pollution of North China Plain is very prominent. Especially groundwater is the main water source and supply. To build a groundwater model and integrate it into the geographic information system (GIS) is an important method to realize the sustainable use and management of water resource of North China Plain. As a result of the clear construction and independent modules of groundwater model program MODFLOW,which is based on the finite difference method, the original program packages could be modified and the new package could also be added into it according to the needs of integration. In this paper the integration relationship between groundwater model and GIS was established after analyzing the input and output data format of groundwater MODFLOW and the geological and hydrogeological data format of North China Plain where most data were mainly composed of MAPGIS format. And it was applied to the groundwater evaluation of North China Plain. According to the hydrogeological condition of North China Plain, the three dimensional transient groundwater flow model was constructed. Parameters were validated using flow net of observation pores in December 2003. and the dynamic water level data between January 2002. and December 2003. The parameters include conductivity coefficient, specific yield and storativity of aquifers. During the process of constructing the groundwater model, a water budget was analyzed, which resulted in a negative budget in the North China Plain. The simulation period was from January 1,2002 to November 12,2003. During this period the total recharge of the groundwater system was 493.74 10⁸m³,and the total discharge was 565.30×10⁸m³,and the budget deficit was -71.56×10⁸m³. The system with groundwater of North China Plain can dynamically evaluate the groundwater resources under the net circumstance by using the source and sink data in database which can provide reference valuable for the use and management of water resource.