Research On The Assessment And Reasonable Development Of Groundwater Resources In Mai-ling Spare Water Source

Xuchang is one of the serious water shortage cities in China,and the shortage of water resources seriously restricts the development and construction of the city.In 1993,water source of MaiLing supply to Xuchang City and alleviate the serious shortage of water in Xuchang City.February 2015,south-north water transfer project supporting of Xuchang City is official completed,urban water supply mainly uses water source of South-to-North Water Transfer Project.Mai Ling water source is planned for the city emergency standby water source.Mai Ling water source in the buried alluvial fan(North Ru River alluvial plain)in the upper reaches,Terrain flat,the water source is divided into shallow and deep layers according to the structural characteristics of the aquifer.There is 2 ~ 12 m thick ginger weak water permeable layer with silty clay between Shallow water and deep water,local less than 2m or greater than 15 m,there is a close hydraulic link between the two,under the conditions of Pumping water,the two are more obvious.Deep aquifer lithology for the gravel layer,thickness,water conductivity and water storage capacity,storage capacity is strong,that is the mining layer of the water source.This paper focuses on the use water balance method and numerical method to Calculation and evaluate groundwater resources.According to the hydrogeological model of the water source,the groundwater equilibrium equation is established,calculated the amount of recharge,excretion and equilibrium difference,and compared with the calculated amount of storage change,its multi-year equilibrium error is less than 10%,it is shown that the equilibrium equation is more realistic and reflecting the hydrogeological conditions of the water source,and the hydrogeological parameters are reasonable and credible.A mathematical model is Established,using Visual MODFlow software for numerical simulation,establishment of numerical model of groundwater flow is Established,that is identified and verified by the long-term observation of water level dynamic data.According to the hydrogeological conditions of water source and mining wells layout,the four development and utilization programs are established,and the groundwater level and flow field of four development and utilization schemes are predicted by using the established numerical model.there is a comprehensive analysis of the program.The results show that the layout of the mining wells and the regulation of the mining amount have a great influence on the local groundwater level of the water source.The optimization scheme can effectively prevent the underground water level in the western part of the water source falling too fast.that contributes to the full development of deep water resources.And that has less impact onshallow water,It can avoid conflicts with the agricultural water use competition,it is conducive to the rational use of groundwater resources.