Research On The Assessment And Sustainable Utilization Of Groundwater Resources In Dingbian County

Dingbian County of Shaanxi Province is located in the north of Baiyu mountain,which is the transition zone between Loess Plateau and Ordos desert.The convenient transportation and the development of oil and gas make the population and heavy industry of Dingbian county develop rapidly.However,there is a lack of surface water in Dingbian County,and there is little research on groundwater resources.Therefore,“Proved groundwater resources,forecast development,sustainable development”has a far-reaching impact on the sustainable development of groundwater resources and regional water resources planning and management in Dingbian county.In view of the above problems,this paper collected a large number of basic data of meteorology,hydrology,geology and hydrogeology,conducted groundwater resource evaluation,groundwater flow numerical model establishment,and groundwater sustainable utilization analysis.At the same time,based on the above analysis,put forward some suggestions for the sustainable development of groundwater resources in Dingbian county.(1)Groundwater resources evaluationAccording to the watershed and hydrogeological conditions,the parameter zoning is divided,and using water balance method to evaluate the groundwater resources of Dingbian county.Through the Pearson rainfall frequency curve,the rainfall infiltration replenishment under different guarantee rates is analyzed,and the total replenishment and total discharge are calculated at the same time.The exploitable groundwater is 34.97×10⁴m³/d by using the exploitation coefficient method.Regarding the particularity of the groundwater environment in Dingbian County,359 sets of water samples were analyzed using the comprehensive index method.The main chemical type of groundwater in Dingbian county is HCO₃·SO₄-Na·Mg,and the total dissolved solids is about 3g/L.The content of sulfate and fluorine in most areas exceeds the standard.And results show that most areas belong to class V water,which is mainly caused by the problems of primary geological environment,gentle hydraulic gradient,slow water circulation speed and other factors.(2)Numerical simulation of groundwater flowGMS is used to establish a numerical model of groundwater flow in Dingbian County,under different mining schemes,to predict the changes of groundwater level.On the premise of hydrogeological conditions,the mathematical model was established to digitize and the space and time were discrete.The results were identified and verified based on 2018 data.Finally,four schemes are designed to predict the groundwater level in the next ten years,and the possible problems caused by groundwater exploitation are analyzed combined with water balance.(3)Evaluation of sustainable utilization of Bossel groundwater resourcesThe Bossel evaluation index system was used to establish a sustainable utilization system of groundwater resources,and the development trend of Dingbian County was evaluated.In response to the problems of water environment and hydrogeology,the system is divided into three subsystems:groundwater resources,social economy and ecological environment.The objective mathematical weight method and improved AHP method are used to calculate the weight values respectively.According to the basic category oriented indicators,the results show that the sustainable utilization of groundwater resources in Dingbian county is in a dangerous situation,and the development index is 1.9365.In view of the short board problem,the prevention and control of water pollution should be done well to improve the utilization efficiency of groundwater resources.Under the condition of coordinated development of each subsystem,the sustainable development of groundwater resources in Dingbian county can be guaranteed.