The Impact Of Duancun-Leigou Bauxite Mining In Simulation And Evaluation Of Groundwater

Groundwater is an important natural resources and it is also an important water for many industrial,agricultural and living.However,in recent decades with the increasing human activity,on the quality and quantity of groundwater resources has caused many negative effects:such as depletion caused by excessive exploitation of water resources,land subsidence,seawater intrusion.Other large-scale mining dewat-ers the groundwater for underground mining will result in rapidly declining ground-water levels around the mines, it brings about a large number of wells abandoned.Duancun-Leigou bauxite located within Mianchi,mining method for the under-ground mining,design of dewatering and displacement of approximately 3×104 m3/d. There are several users who use groundwater as a water users.The bauxite mining is bound to speed up the rate of decline in groundwater areas. This article is on the basis of collecting hydrogeological data to simulate and predict groundwater assessment in the area.Main results are as follows:(1) On the basis of comprehensive analysis hydrogeological conditions,a conceptual model of groundwater system is built base on the abstraction and genera-lization and use Visual Modflow to simulate and fit the groundwater flow field in the area, the simulation results are good.(2) Use the model validation predicte the different scenarios of groundwater flow characteristics,by the projection analysis and comparison we kan know:①Under the status quo the groundwater level is showing declining trend and small decline in the western,quick in the middle and east.②Under the status quo the groundwater level is slower decline and can not meet the infrastructure requirements of the minimum water level elevation,so drain-age is necessary in order to prevent the occurrence of water inrush.③After mining,the water drainage accelerated the decline in groundwater levels and the formation of the funnel.According to the comparative analysis before and after mining,in the end of the forecast period (21 years),the water level dropped by about 0～5m in the west,and 20m in the middle,0～10m in the ease. And add 2 cone of depression,funnel water table down the center approximately 80m in the Duancun mining section.④The mining will have a greater impact on the water source in the area,the maximum impact strength is in the middle region,and smaller in the western and eastern. After 21 years of mining the No.11 well, No.14 well and No.2B well were scrapped,the NO.7 well needs replacing lift pump to use.