Numerical Simulation Research Of Groundwater With MODFLOW In The JinQuan Industrial Park

Groundwater resources are not inexhaustible, and with the development of the economic and society, the improvement of people's living standard, the demand for groundwater have increased much, therefore will produce a series of environmental geological problems, especially the excessive extraction of groundwater has lead to a sustained decline in the regional water table, the scientific management of groundwater resources is imperative.The study area belongs to the arid and semi-arid regions, a typical temperate continental climate. Its characteristics are: winter cold and long, summer hot and short-livid. Dramatic changes in summer and winter, less precipitation and concentrated. Strong evaporate, and rich in luminous energy. The region's main water source is the groundwater, with the utilization of groundwater resources increased year by year, environmental problems have become increasingly prominent, and therefore, the simulation and prediction of the study area have some practical significance and reference value.This paper first reviews the research status and recent progress of the numerical simulation of groundwater, summarizes the main strengths and weaknesses and focus on the numerical simulation. Then, we introduce the study area topography, hydrogeology characteristics of the basic conditions, to determine the structure and the groundwater aquifer type, groundwater recharge, runoff and discharge conditions and the type of groundwater. On this basis, establish the hydrogeology conceptual model of the study area.The hydrogeology conceptual model based on the hydrogeology conceptual model, MODFLOW simulation model used to solve software. In the identification period ,from the level fitting chart ,we can see that the average of water level error of diving observation wells is 0.185m,the RMS(Root mean squared error) is 0.327m, more than 85% of the total observation well's fitting error is less than 0.5m,From the fitting chart of the typical observation well J34,J32,we can see the measured water level and the calculated water level reached a good fit. This shows that the establishment of the hydrogeology conceptual model and mathematical model is correct and reliable. In the test period, we can get from the test fitting results that the average absolute error of diving well level is 0.664m, of which error is less than 0.5m occupies 84.2% of the total observation wells.Predict the rainfall of the study area in the next 20 years use the Monte Carlo method, then according to differences of hydrogeology conditions of the production well to determine the mining plan, put the mining wells to the central part of the detailed investigation area, select the ocean current map Alluvial Fan which is thick,strong permeability and has the ability of regulate. Entered the source and sink items of the forecast period into the identified and validated numerical model to predicting the programs. In the prediction model, the drawdown change with time of the typical observation hole is one important criterion to determine the amount of available groundwater resources. At last, we can get different mining plans, the groundwater flow patterns and the typical water level observation well fitting chart for that mining for 10years and 20 years. Finally, we employed the Nemerow integrated pollution index to study the environment quality of groundwater, the mathematical process of the method simple and convenient operation. We obtained the water quality of the observation points and excessive component in the study area after computing.