Numerical Simulation Based On Groundwater Modeling System On Alluvial And Silted Valley Plain

Water is the source of life, it has double attribute of basic natural resources and strategic economic resources. Groundwater is an important part of water resources, it is important factor of compositing ang influencing ecological environment, and it is regarded as "scarce resources" in dry regions. Groundwater is an important supply source for city living, industry and irrigation, it plays an extremely important role on regional economic and social development. But for a long time, especially in recently 20 years, because of development of national economy and improvement of people's living standard, it demands for water resources rapidly. With the increasing of groundwater exploitation and lacking of water management, it is occurred the phenomenon of groundwater overexploitation in many regions. As the same time, it is leading to water level falling, land subsidence and salt water intrusion etc serious environmental problems. It is ruinned people′life and property and losed economic by many environmental geological disasters.Based on the analysis of materials such as landform, terrain, hydrometeorological, and hydrogeology, elaborated the stratum lithology systematically of the study area, this paper analyzed the occurrence condition distributed rule of groundwater and analyzed the rule of supply, runoff, deposit and drain of groundwater and its dynamic characteristics. According to water abundance, it located the proposed water source area.With the help of GMS6.0 software, a simulant model is constructed for studying the flow of groundwater in study area, including the 3D hydrogeology visual model and numerical simulation model. Firstly, TIN module and SOLID module which is part of GMS software, is used to build the surface triangulated irregular net-works model and 3D hydrogeology visual model. It can present the syntagmatic relation of aquifer on angle of three-dimension,and it is benefit to recognize the hydrogeology of study area.After the hydrogeology conceptual model is constructed, the mathematical model of the study area is built.Using the MODFLOW module of GMS sofeware to simulate, calibrate and verify, it is perfect fit between computed value and observed value from result of the model calibration and verification, and the computed value largely reflects the trend of groundwater flow.After that, According to the exploitation project, it predicted the the trend of groundwater flow and max drawdown for different exploitation project through running the calibrated and verified model. At the same time, considering the most unfavorable condition, this paper use interference-wellgroup method to predict the the max drawdown for different exploitation project. Because of different assumed condition, the result of prediction is different. This paper analysed the results detailedly. The predicted results indicates that the max drawndown of xploitation project 1 and 2 is not exceeded the max allowable drawndown.The xploitation project is reasonable and feasible. Considering saving construction investment and maintenance cost, this paper recommends the xploitation project 1.From the above, with analyzing and evaluating the xploitation project ,this paper use different methods to predict the max drawdown,which can be used as references to the rational exploitation of groundwater in the study area.