Simulation Of Groundwater System Evolution In The South Mining Area

The hydrogeological conditions of China's coal mines are extremely complex,which often composed of multi-aquifer complex system.The fourth aquifer in Quaternary(QA),the sandstone aquifer(SA)and the limestone aquifer(LA)in the Sunan mining area was taken as research object.The 3D geological structure model was generalized into six aquifers and established by FEFLOW 3D hydro-geological structure model.The model data was based on the hydrogeological data and hydrochemistry data from July 2009 to July 2014.The spatial characteristics of groundwater flow field were analyzed from the groundwater level,water pressure and the groundwater seepage velocity field.The characteristics of groundwater flow and the evolution of groundwater were analyzed from the groundwater flow field and water chemistry,which had revealed the path of groundwater,predicted the evolution trend of groundwater field and water chemistry field in Sunan mining area.The results show that the coupling degree between the groundwater flow field and the water chemistry field was high.The main factors influenced the aquifers was folds and faults,and its influence was gradually weakened from the SA in the Sunan mining area.The aquifer in the Sunan mining area was divided by anticline and fault into three regions: western,central and eastern.Groundwater system of the eastern QA was independent.Besides,the hydraulic connection between the Western Zouzhuang and Central Qinan in the SA,between the Estern Zhuxianzhuang andthe Central Taoyuan in the LA were fairly direct.The groundwater in SA would flow to the upper aquifer in the Zouzhuang and in the weathering zone.In three simulation periods,the groundwater level and the water chemistry content decreased years by years,which leaded to the groundwater flow to inrush region and the content of TDS increased gradually in the inrush region.The groundwater flow field and water chemistry field would continue the current development trend with the exploitation of the mining area,and the groundwater flow path would not change in the future.In this paper,a reliable groundwater numerical model had been established and it can provide theoretical support for water hazard prevention and groundwater source identification in the concealed coal mining area in North China.