Investigation and Prevention Measures of Filling Water Source in Open Pit Coal Mine at the boundary between Shaanxi and Mongolia

The open pit coal mine is located between Wulan Mulun Town, Ejin Horuo Banner, Ordos City, Inner Mongolia Autonomous Region and Daliuta Town, Shenmu City, Shaanxi Province, where the Wulan Mulun River and the Xiaohe River intersect. In recent years, as the area of open-pit mining increases, the amount of pumping and draining groundwater is also increasing year by year. In order to reduce the discharge of groundwater and protect the water resource better, the investigation and study of the water-filled source in open-pit coal mining are carried out for providing technical basis to future water resources protection and management.Through comprehensive investigation and analysis of hydrodynamic field, hydrochemical field and isotope field, it is concluded that the source of filling water in open-pit coal mine is mainly surface water（water from the Ulan Mulun River,the Xiaohe River and the Ulan Mulun River reservoir）, followed by the lateral radial flow of bedrock fissure water and atmospheric precipitation. Due to the large water leakage form the rivers, surface water and water reservoir, the reservoir capacity and the river water is reduced or cut off. If not to take prevention and control measures, it may cause damage to the local environment. In order to protect the water resources, the leakage sections of the Wulan Mulun River and the Xiaohe River should be blocked in time, and the seepage prevention treatment should be done to reduce the infiltration of surface water.At the same time, a monitoring system of surface water and groundwater should be established to monitor the environmental elements related to the dynamic changes of surface water and groundwater and mine construction and production, so as to prevent deterioration and spread, give early warning and provide a basis for environmental governance.