Study On Ecological Space Control And Balanced Exploitation Technology Of Urban Water Source In Yinchuan,Ningxia

As an important part of water resources,groundwater is not only the main water supply source to support industrial and domestic water in Yinchuan City,but also the supplementary water source for agricultural drought resistance.It is also one of the supporting conditions to maintain oasis ecosystem.With the rapid expansion of Yinchuan city scale,urban development has occupied the water source protection area,the water quality of urban groundwater source is deteriorating,and the urban living and industrial water quality is increasing And agricultural water has been exploited for a long time,forming groundwater overdraft area,and the difficulty of water source protection has gradually increased.Aiming at the existing groundwater environmental problems in Yinchuan area,based on the idea of ecological space management and control in the ecological protection red line,this paper studies the delimitation principle of the ecological space of the water source area.At the same time,through the establishment of regional groundwater flow numerical simulation model,the future flow field changes and water level drawdown are predicted,which can provide reference for the protection and pollution prevention of groundwater resources in Yinchuan City,and improve the quality of water The water environment of water source is safe.The main research contents and conclusions are as follows1.Part of groundwater source areas in Yinchuan city are located in irrigation area.The process of groundwater vertical recharge is easily affected by agricultural planting,which leads to high ammonia nitrogen content.Some groundwater source areas are located in over exploitation areas,and the utilization rate of water resources has approached the upper limit.Because the urban development occupies the water source protection area,the difficulty of water source protection increases year by year.2.Based on remote sensing image data,3S technology is used as the main means,and single factor evaluation and multi factor comprehensive evaluation methods are used to put forward the ecological red line division method of water source area based on the importance theory of ecological protection.By using spatial analysis and overlay analysis technology,the protection red line range of water source area in the northern suburb of Yinchuan city is about 20.72 km~2,and the protection red line range of water source area in the eastern suburb of Yinchuan city is about 12.92km~2,and the red line of water source protection in southern suburb of Yinchuan city is about 7.17km~2.3.Through the establishment of groundwater flow numerical model in water source area,the dynamic change of groundwater level in the future is predicted.The first scheme is to ensure that the current mining amount remains unchanged.Five years later,the average drawdown of regional water level is 1.6m,and the maximum drawdown is 2.5m.Ten years later,the average drawdown of regional water level is 2.2m,and the maximum drawdown is3.2m.Twenty years later,the average drawdown of regional water level is 2.8m,and the maximum drawdown is 3.8m.The second plan is to increase the set mining amount by 30%on the basis of the current situation.After five years,the average drawdown of regional water level is 3.2m,and the maximum drawdown is 4.3m.Ten years later,the average drawdown of regional water level is 5.0m,and the maximum drawdown is 7.0m.Twenty years later,the average drawdown of regional water level is 7.5m,and the maximum drawdown is 10.3M.The third scheme is to reduce the set mining amount by 30%on the basis of the current situation.Five years later,the regional water level rose by 0.2m on average,and the maximum water level rose by 0.4m.After that,the water level did not change.Although there was still a mining funnel,the groundwater reached a new dynamic balance.4.According to the existing problems and potential risks of drinking water sources,it is proposed to control the ecological protection space of drinking water sources through the combination of rigid measures and elastic measures.At the same time,in order to achieve the balance between mining and supplement in the groundwater overdraft area and eliminate the phenomenon of groundwater overdraft,it is proposed to take corresponding measures such as total amount control,pressure mining and replacement to eliminate groundwater overdraft,Effective protection of groundwater resources.