基于GIS技术的浅层地下水硝酸盐氮浓度场数值仿真

Numerical Emulation of the NO_3^-Concentration Field of Groundwater System

地理信息系统(GIS)技术与数值模拟技术相结合,揭示地下水硝酸盐氮浓度场的时空变化特征。采用准三维数值仿真技术,建立地下水水流模型、溶质运移模型和地下水运动方程组成的地下水水质模型。先解地下水水流模型,得到地下水渗流场水位函数H(x,y,t);再解地下水运动方程得到各单元的地下水实际流速;最后解溶质运移模型,求出计算区内任一点的硝酸盐氮浓度。数值模拟与空间分析结果表明,研究区地下水水质系统状态比较稳定,硝酸盐氮浓度场的时空分布变化较小。

Geographical Information System (GIS) and numerical emulation are combined to study the distribution of the NO3- concentration in the groundwater system. Based on conception model of groundwater system, the groundwater quality models of the research area are established. It includes the model of groundwater flow, the model of solute movement and the model of ground water motion. Firstly, the model of groundwater flow is solved for H(x,y,t); then the model of groundwater movement is solved for actual velocity of groundwater flow in every unit; and the solute movement is solved for the NO3- concentration of the every point in overall research area. The consequence of numerical emulation and spatial analyse make known, the dynamic of groundwater quality system is relatively stabilization, the dynamic changes of temporal and spatial of the NO3- concentration are relatively steady in the research area.