Study Of The Impacts Of Strip Mining On The Groundwater Environment

Under the background of serious groundwater environmental problems caused by strip mining, Yimin NO.1open pit was taken as the research object. Affect caused by strip mining will be analyzed from two aspects:the first is groundwater quality, and the second is groundwater resources. By the comparison of the different periods of groundwater quality monitoring results, we can draw a conclusion that High geological background value is the main reason for the excessive of Fe and Mn, and livestock production is the main reason for the excessive of Ammonia. The extent of groundwater contamination was assessed with Nemerow comprehensive pollution index. The results show that10%of the monitoring points in moderate pollution levels,20%of the monitoring sites in the mild pollution levels,40%of the monitoring sites in the alert level, only30%of the monitoring sites at a safe level. At the same time, hydro-geological conditions, groundwater level changes in different periods, the change of the flow field and dewatering range as the analysis of groundwater resources in four areas to be analyzed. The flowing conclusions were drawn.(1) Coal seam is the mainly confined aquifer and the strong hydraulic conductivity layer. It has more rich water and water permeability than the unconfined aquifer. Aquifer of open pit is the main pressing region and the discharge area. The impact of fault in the area on aquifer is very significant.(2) Groundwater level continued to decline, and its’decrease amplitude is little connected with rainfall, and it is mainly affected by the impact of dewatering.(3) The hydraulic gradient of groundwater is gradually increasing with the continued exploitation of open pit coal mine. Groundwater flow field is mainly decided by the geomorphology and fault become by the location of the open pit. Open pit instead of rivers and lakes become the main discharge zone. Rivers and lakes begin to recharge groundwater. The dewatering funnel is gradually increasing, and its’direction of transfer same with the direction of the coal mining.(4) The emission of dewatering water in Yimin open pit has been stable. It will have little impact on drinking water sources, Yimin River and residential drinking water.