Study On Groundwater And Soil Environmental Response In Opencast Coal Mine Area

Coal mining is the process of artificial transformation of the natural system.The negative effect of the ecological geological environment revealed in the coal mining area is the synthesis of various ecological and environmental elements in response to the conversion from the natural geological environment system to the artificial composite system.The mining of opencast coal mine can easily destroy the original characteristics of the regional groundwater flow system,which leads to the change of soil types,moisture content,salt content and nutrients in the affected area,and adversely affecting vegetation growth,population structure,and biodiversity.Therefore,the research on the response of groundwater and soil environment in opencast coal mine area is the most important research at present.In this paper,the groundwater and soil in Yimin opencast coal mining area of Hulun Buir grassland are taken as the research objects,and the mathematical statistics,Gibbs diagram,Piper diagram,Durov diagram,Kourlov type,saturation index,isoline diagram and linear fitting method are comprehensively used.The analysis of groundwater and soil environment status in the area revealed the effects of changes in groundwater level and water quality on the soil moisture content,salt content,and organic matter under the influence of coal mining.The main results obtained are as follows:?1?The groundwater in this area is generally in a weakly alkaline and strong reducing environment.The chemical composition of groundwater is mainly affected by the interaction of water and rock and evaporation and concentration.The dissolution of feldspar and carbonate minerals in this area is the main groundwater source of HCO₃^-?Na⁺?Ca²⁺.?2?The main changes of soil environment before and after opencast coal mining are mainly reflucted in:the p H,EC and F content increased significantly,the content of soil moisture,bulk density,organic matter,total nitrogen,total phosphorus and available nitrogen decreased,and the content of Pb,Zn,Cr,Cd,Hg,S and As did not change much.?3?Under the influence of opencast coal mining,the groundwater level in mining area decreases significantly,which makes soil moisture content and organic matter obviously decrease,but has little effect on soil salt content.With the increase of distance,the influence of coal mining weakens with the pit as the center,and the soil gradually returns to its natural state.?4?Under the influence of coal mining,the groundwater level has positive correlation with soil moisture content and organic matter.The groundwater pH has a negative correlation with soil moisture content,and has a positive correlation with salt content and organic matter content.The groundwater TDS was negatively correlated with soil moisture content and salt content,and positively correlated with organic matter.