Study On Influence Of Mining On Groundwater Flow Field Around Naomaohu Mining Area

Xinjiang Yiwu Nomaohu mining area(hereinafter referred to as Nomaohu mining area)is located in Xinjiang Uygur Autonomous region Hami City Yiwu County,Balikun County.Climate types in this area belong to Mainland temperate arid climate with less rainfall and strong evaporation.The uneven distribution of water resources in time and space makes the region face engineering water shortage and water shortage,and there are two major water shortage problems.In the process of coal mining,water shortage is becoming more and more serious,which can easily lead to the shortage of industrial and agricultural water and domestic water in the surrounding areas of mining area.At the same time,due to the influence of mine drainage and domestic water,many adverse environmental geological problems are easy to occur around the mining area.Therefore,It is necessary to predict and analyze the influence of mining conditions on the surrounding groundwater level in Naomaohu mining area,to provide some theoretical support for ensuring the sustainable development of the region's economy,and to provide certain technical support for the mining work in this area at the same time.Based on the hydrogeological conditions and actual geological conditions of the study area,the hydrogeological model of the study area is established.The model is corrected and identified by the water level observation data in the study area.Finally,the model parameters are used to predict the influence of coal mining on the surrounding groundwater level.This paper simulates the whole process of mining in Naomaohu mining area,and studies the water inflow,the range of flow field and the variation of groundwater level at different times through the comparison of the calculation results of the two planning schemes.The main conclusions are as follows:1?With the exploitation of Naomaohu mining area,the original water cycle mode and water balance state of groundwater system have been changed.The mine drainage will be composed of intercepted discharge reduction,stimulated recharge increment and consu med storage.With the development of coal mining,the decline range of the surrounding groundwater level will continue to increase,at the same time,it will stimulate the lateral recharge of groundwater,intercept the original evaporation and spring disch arge of groundwater.Because of the difference of permeability,depth of water level and discharge mode of groundwater in the north and south part of the mining area,the influence range of depth drop in the north of the mining area is much larger than that in the south of the mining area.2?Through the simulation of the whole mining process of Nao Maohu mining area,the groundwater level drop around Nao Maohu mining area at different times is calcula ted.Under the mining scheme of scheme 1,the influence scope of the surrounding groundwater drawdown of more than 1m in the 10th,100th,final and 9th year after mining is599.10km~2,2662.30km~2,2972.91km~2 and 3023.99km~2 respectively;under the mining scheme of scheme 2(the mining time of No.2,No.3 and No.4 coal mines in the mining area goes back),the mining area of Naomaohu coal mine is relatively stable In the 10th,100th,last and 9th year after exploitation,the influence area of groundwater drawdown greater than 1m is 482.07km~2,2659.88km~2,2972.61km~2 and 3024.94km~2 respectively.Scheme two has little influence on the surrounding groundwater level compared with scheme one in the early stage.With the development of coal mining,the influence range of coal mining on the surrounding groundwater level is increasing,and by the end of mining,The influence range of scheme two on the surrounding groundwater level is larger than that of scheme one.3?The prediction results of the model show that under the mining conditions of scheme 1,the water inflow of the pit at the end of the 10th year of mining in Naomaohu mining area is 59917.5m~3/d,of which the net release of storage is 36226.6m~3/d,the intercepted discharge is 23690.9m~3/d,the mine water inflow in the 100th year is110074.3m~3/d,the net release of the storage in the mine is 133907.6m~3/d,the intercepted discharge is 23690.9m~3/d,and the net discharge at the end of mining period is-23690.9m~3/d The water inflow of the mine is 14424m~3/d,including the net release of the storage amount of 67336.6m~3/d,the intercepted discharge is 52912.6m~3/d;under the mining conditions of scheme 2,the water inflow of the pit at the end of the 10th year of the mining in Naomaohu mining area is 56292.9m~3/d,including the net release of storage amount of 33821.6m~3/d,the intercepted discharge of 22471.3m~3/d,and the mine water inflow in the 100th year is 124897.3m~3/d,including the storage capacity The net release is109401.2m3/d,the intercepted discharge is 15496.2m~3/d,the mine water inflow at the end of mining is 14391m~3/d,of which the net release of storage is 68147.6m~3/d,and the intercepted discharge is 53756.6m~3/d.Scheme 2 Comparison Scheme 1 Because of the reduction of coal mining in the early stage,the mine water inflow in the early stage of mining planning is reduced compared with that in the first scheme.4?The results of model prediction show that scheme 2 and scheme 1 have little impact on the national secondary public welfare forest in Niuquan lake and the west of naomao lake,and they are basically the same.At the same time,the impact of the two schemes o n the groundwater level of the desert park is also small.Because scheme 2 reduces the amount of coal mining in the early stage,the impact on the desert park lags behind scheme1.5?The prediction results show that the two mining schemes have the same impact on the basic farmland protection area,and have little impact on the groundwater level of the farmland protection area.6?By comparing the prediction results of the two schemes,it is concluded that the impacts of the two schemes on Niuquanhu water source,Ma 56 block water source,Naomaohu water plant,Guanghui energy water source and mechanical(civilian)wells in Naomaohu irrigation area are small,and the impact of scheme 2 is less than that of scheme1 because scheme 2 reduces the coal mining amount in the early stage.