Research On The Shallow-Central Groundwater System Under The Influence Of Mining

Groundwater resources are the water resources that human beings rely on for survival.With the rapid development of society and economy,the dependence on groundwater resources is getting higher and higher,especially for the Ordos Basin in western my country where water resources are scarce.From the long-term monitoring and analysis of groundwater dynamics in the development of mineral resources,it is found that human mining activities have a greater impact on the dynamic changes of groundwater,which not only reduces the storage of groundwater resources,but also changes the groundwater flow system,which is essential for mine water hazard prevention and ecological protection.There are abundant coal resources in the Jurassic strata in the Ordos Basin,which is threatened by the water hazard of its roof sandstone during mining.Therefore,diswater and mining drainage are carried out,causing different changes of groundwater level for each aquifer and continuing decreasing leads to serious ecological problems This paper takes some mine in the northern Erdos as an example,which is located in a small watershed.Through preliminary hydrogeological exploration and production process surveys,using the mine's main aquifer water level and underground water inflow monitoring data from 2014 to 2019,the dynamic changes of the groundwater level before and after mining were systematically analyzed,and the groundwater flow field change law was explained,and numerical values were used.Simulation method to identify the parameters of the aquifer in the study area,simulate the change process of the groundwater system caused by its mining,and analyze the factors such as the sedimentary environment,lithological structure,geological structure,the permeability and water richness of the aquifer in space and the influence of mining.The control factors for the changes of groundwater flow field are discussed,and different stages of models are proposed.The main conclusions and understandings are as follows:1.Due to the late diagenesis of the Jurassic and Cretaceous strata,their structural characteristics and their composition determine the characteristics of poor consolidation and poor rock stability.Quaternary loose layers are widely distributed in the study area,which lays favorable conditions for the groundwater system to be changed after the groundwater is drained,which in turn leads to related problems such as coal roof falling after partial mining.2.Under natural conditions,the groundwater system continues to evolve spontaneously.During underground drainage,the flow field of the Cretaceous aquifer basically remains unchanged,while the Jurassic water level drops sharply,and the deep groundwater system is greatly affected.Coal seam mining causes vertical cracks development,destroying the water barrier between the two aquifers,and promoting the formation of a unified groundwater system.3.By comparing the groundwater flow field at different stages of each aquifer,it is found that only in the mining phase of the working face,the Cretaceous groundwater level shows a downward trend,with the maximum water level drop reaching 30m,and a drop funnel centered on the stope is formed.4.It is further studied and found that the fluctuation of surface water controls the direction of surface water runoff and phreatic water flow,which is basically the same;the paleogeomorphology and structure controls the change of deep groundwater flow field;human mining activities change the local groundwater flow field of the basin,and exacerbate the deterioration of the surface ecological environment.5.Through the establishment of a numerical model,the characteristics of the groundwater flow system changes under natural conditions,under the conditions of dewatering and under the influence of mining disturbances are described from the level and profile of the aquifer flow field,which are in line with the actual situation.In western my country,the above-mentioned research results provide a new path of thought for the rational evaluation and sustainable utilization of groundwater resources in mining areas.The three types of groundwater flow system formation models reveal that natural conditions and human activities are combined the mechanism of groundwater system change provides a reference for the rational drainage of groundwater and ecological environment protection in the process of mining.Figure[51]table[7]Reference[88]...