Sundy On Environmental Impact Of Ground Water Based On Reservoir Dam Site Selection Schemein In Hilly Area

Reservoir dam seepage could not only affect the security and stability of the dam by harmful infiltrated sabotage, but also change the basic characteristics of rivers and hydrological regime of downstream rivers. Also, it will impact the surrounding groundwater environment. Thus, in order to identify the reasonability of the dam programs choice, it is necessary to predict and consider the impact arising from groundwater seepage.Youfanggou reservoir project is a hydraulic engineering for integrated water using. The project is located in the north of Yilong County, near Rixing town that belongs to Bazhong city. The dam is located near Youyi Bridge which lies downstream of the mouth of the trigeminal river sinks from riverhead that upstream of Youfanggou reservoir. The normal water level is406.00m, design flood level is406.09m, check flood level is407.64m, and dead water level is395.00m. Its exploiting mission is to irrigation, living water in town and drinking water in rural areas.In this paper, Youfanggou reservoir dam in hilly area will be selected as the research object. Firstly, survey geological environment including topography, geological structure and lithology etc. Secondly, research the hydrogeological conditions such as the type of groundwater, aquifer watery, groundwater recharge and discharge conditions and chemical characteristics etc. On the basis, establish a conceptual model of groundwater systems and generalized model boundary, while establishing and verifying numerical models of groundwater systems. Thirdly, predict groundwater seepage field changes and analysis the impact on the surrounding groundwater environment after water impoundment by using of Visual MODFLOW software. Then, by modeling and calculating surrounding groundwater environmental impact through seepage, this paper will analysis the difference between different dam site selection. Finally, by comparing the results of the analysis, verify the reasonableness of the dam site selection from the perspective of groundwater environmental impact.