Evaluation And Optimal Allocation Of Groundwater Resources In Lankao County Based On Modflow

Lankao County is located in the middle reaches of the Yellow River,mostly agriculture and industry.In recent years,with the increase in population and the development of industrial economy,groundwater has been polluted to varying degrees,and the water level has dropped significantly,forming a large-scale falling funnel,which has aggravated the contradiction between the supply and demand of groundwater.On the basis of fully analyzing the hydrogeological data of Lankao County,the drinking water quality of the study area was systematically evaluated by means of field geological survey and water sampling,and using single index evaluation method and F-value scoring method.Then use the regional water balance program of Modflow software to specifically evaluate the amount of shallow groundwater resources in Lankao County,and compare and analyze the evaluation results with the water balance method.The following results have been achieved:(1)The pollution of shallow groundwater in Lankao County is relatively serious,mainly due to excessive iron and manganese content.Among them,the area of direct potable water accounts for about 7.99%of the total area of the study area,the area of Class IV poor quality water accounts for about 41.77%of the total area of the study area,and the area of Class V poor quality water accounts for about 50.24%of the total area of the study area.The overall water quality The west is better than the east.(2)The method of combining water balance method and numerical simulation is adopted.In view of the fact that the maximum recoverable amount obtained by the water balance method is too large,the evaluation result of numerical simulation is finally adopted:the total replenishment volume in Lankao County area is more than the total discharge volume in the whole year.Less than 560.72×10~4m~3/a,the maximum mining capacity is 15062.66×10~4m~3/a.(3)Combining the water quality and quantity of the study area,the shallow groundwater development and utilization can be planned into three areas:directly potable groundwater area(A area),properly treated potable groundwater area(B area)and unsuitable for drinking groundwater area(C area),play a role of reference and guidance for the development of Lankao County.