Water Resource Evaluation And Mining Scheme Analysis For Water Supply In The Northeastern Of Xi'an

Water supply is an important facility in Xi'an,because the ground water source can make up the shortage of urban water supply and provide reliable water supply for the economic or social development of city.Among them,emergency water supply project can provide backup water for production to guarantee the safety of urban water supply and improve the ability of risk prevention.Therefore,it is necessary to build urban emergency water source.On the basis of data collection,field investigation and pumping test,the present situation of groundwater resources and the designed mining scheme in the water source area of the northeastern suburb of Xi'an are studied in this paper,and the following achievements have been obtained.(1)the distribution characteristics of aquifer and the law of groundwater dynamic change are analyzed.The hydrogeological parameters of aquifer are calculated by pumping test data and previous work.The hydraulic conductivity of the unconfined aquifer,shallow confined aquifer,deep confined aquifer is 24.32 m/d,18.46 m/d,24.55m/d,respectively.At the same time,the parameters of hydraulic jump,specific yield and elastic release rate are also determined which prepared for water resources evaluation.(2)the water balance method is used to calculate the recharge or discharge of the phreatic water and confined water in the equilibrium period based on the analysis of the factors of groundwater balance area.In unconfined aquifer,the total recharge is 2871.45×10~4m~3/a,the total discharge is 2308.74×10~4m~3/a.In confined aquifer,the total recharge is998.57×10~4m~3/a,and the total discharge is 378.18×10~4m~3/a.(3)a numerical model of groundwater flow is established by Visual Modflow,and the reliable hydrological and geological parameters are obtained through the model generalization,solution and correction,the mining scheme of pumping wells in the water supply is predicted by using correct model.By analyzing the schemes,the second scheme is determined to be a reasonable mining plan,and its exploitation amount is 101280m~3/d.(4)the groundwater and surface water quality in the study area are evaluated by the single evaluation method and the comprehensive evaluation method.It is considered that the groundwater in the study area should be supplied after treatment,and the surface water is suitable for drinking and life.