Study On The Treatment Of Groundwater Over Exploitation In Xianyang City

As an important source of water supply,groundwater resources play an important role in regional economic development,industrial and agricultural production,domestic water consumption and so on.With the rapid development of social economy and the increasing demand for water resources,the continuous over exploitation of groundwater leads to the continuous decline of groundwater level,and then causes a series of environmental problems such as ground fissures,building fissures,groundwater quality pollution,etc.,which have a certain impact on the social and economic development and production and life of the city.Therefore,it is of great significance for the rational utilization and protection of water resources in the over mining area of urban groundwater to fully understand the utilization degree of groundwater,find out the existing problems in the development and utilization of groundwater in time,establish the management system of over mining area and formulate the corresponding control plan.Taking Xianyang city of Shaanxi Province as an example,through collecting the data of meteorology,hydrology,topography and regional geology,this paper summarizes the existing research results of water resources evaluation in the research area,and puts forward a set of control scheme for the over mining area of groundwater suitable for Xianyang city.The main research contents and conclusions are as follows:(1)Based on the full collection of meteorological,hydrological and geological data of Xianyang City,this paper combs the history and current situation of groundwater development and utilization in the urban area of Xianyang City,and comprehensively analyzes the geological conditions of the urban area of Xianyang city by considering the four aspects of water bearing medium characteristics,groundwater flow characteristics,boundary conditions and water balance analysis in the study area.(2)Through determining the groundwater resources of the phreatic aquifer in the study area:124.4293 million m3,and the groundwater resources of the shallow confined aquifer:68.0578 million m3,the repetition amount is 54.6405 million m3,and finally the groundwater resources of Xianyang city is 137.8466 million m3;The data of 9 water quality monitoring wells in Xianyang urban area were selected,and the single component evaluation method,comprehensive index method and entropy weight-fuzzy comprehensive evaluation method were applied to the water quality evaluation calculation to evaluate the groundwater quality in the study area.The evaluation results indicated that the study area The total number of E.coli and bacteria in the groundwater is seriously exceeded,and the total dissolved solids,total hardness and sulfate also exceed the standard.The main types of water chemistry are SO4-Ca and HCO3-Ca.(3)According to the hydrogeological conditions,hydrometeorological data,dynamic monitoring data of groundwater level and mining data in the study area,a numerical model of shallow groundwater flow in line with the actual hydrogeological conditions of Xianyang is established,and through the adjustment of model parameters and source sink terms,a more ideal simulation result is finally obtained.(4)In different levels of the year,starting from the three aspects of residential water use,industrial and agricultural production,and social and economic development,the water resource demand and allocation methods are combined with engineering measures and non-engineering measures,and the treatment plans of groundwater overdraft areas are formulated under different scenarios.Combined with the urban water resources planning,the paper puts forward the countermeasures to realize the rational utilization of groundwater and the protection of groundwater over mining area in Xianyang city.Based on the practical application,this paper combs the current situation of the development and utilization of groundwater resources in urban areas,explores the key problems in the evaluation of groundwater resources and water quality,quantitatively establishes a flow numerical model in line with the actual hydrogeological conditions of Xianyang City,and sets different scenarios of groundwater overexploitation treatment schemes according to the groundwater regulation and management objectives.The results show that the three schemes are suitable for the treatment of groundwater over mining area,and the scheme of proportional pressure mining is the best.At the same time,the paper puts forward the corresponding countermeasures for the control and protection of groundwater overexploitation in the study area.The research results can provide scientific support for guiding the construction of groundwater resources management and strengthening supervision and management.