Application And Study On Groundwater Quality Model Of Shizuishan City

On the basis of systematical analysis of the conditions of hydrogeology and groundwater pollution and resources in Shizuishan city, Ningxia province, the groundwater quality models were proposed in this paper. The finite difference method was applied to simulate the movement of contaminant in the shallow ground water in Shizuishan city by means of the Processing Modflow software. The research results provided the base for predicting the effect of irrigating the greenwood by using middle-water for a long time. It is of a great significance to protect groundwater resource areas and improve the bio-environ conditions. The main research results are summarized as following:1. The research area consisted of a single phreatic aquifer and "double-layer structure" aquifer was simplified as a phreatic aquifer, which was divided into five subregions owing to the complexities of hydrogeological structure of the research area. On the foundation of reference researches, the original values of hydrogeological parameter of each subregion were calculated respectively and the boundary conditions were identified.2. The groundwater flow model in Shizuishan city was presented in this paper. The groundwater flow model into which the initial values of hydrogeological parameters were inputted was calibrated according to the comparison between the calculated values and the observed values of groundwater hydraulic heads from 1992 to 1995, and through much trialing thehydrogeological parameters such as hydraulic conductivity and storage coefficient were calibrated. At last the groundwater flow model was tested by means of the observed data of groundwater level from 1996 to 1999.3. The mathematical model of contaminant transportation in groundwater was proposed in this paper. The chlorine ion was used as simulated ion, and using the MT3D package of PMWIN software to simulate the way of the contaminant movement in groundwater to get the diffusive degree. By comparison between the computed data and observed data this model was modified.The results of numerical simulation show that the calculated values are in good agreement with the observed data, the simplified assumptions are practical, and that some values of hydrogeological parameters in each subregion are rational.