Groundwater Numerical Simulation And Optimization Analysis Of Mining Scheme In Pingtan Underground Reservoir

Pingtan located in the Eastern Sea area of Fujian province,it is the first trial comprehensive experimental area of economic science development in the west of the strait,but the shortage of water supply seriously restricts the development of Pingtan social economy.Therefore,combined with hydrogeological conditions in Pingtan,the feasibility of constructing underground reservoir in the northern part of Pingtan Po was preliminarily studied,the site of underground reservoir was determined,the underground dam,recharge system and mining system were planned,and the visual Modflow was used to simulate At the same time,a new type of reverse filtration reinjection is designed.The following conclusions are drawn:(1)underground reservoirs can be built in the northern part of LuYang,and the actual total capacity of underground reservoirs is about 26.89 million m~3;(2)The runoff rain and flood of the Jun mountain and the LongTou mountain on the two sides of the Pingtan,which belongs to the surface waterⅢ,can be used as the groundwater recharge source of the underground reservoir in Pingtan Lu Yang,and can establish the groundwater recharge system and the island water supply system;(3)compared with the original recharge well,the new type of dual recharge well with filter layer is designed to increase the 395~414%of the single-well recharge volumn,and has the strong stronger anti-rush capability,and to save the gravel material.(4)Considering the holocene series wind-blown,morine sedimentation sand as the reservoir capacity,the amount of water available in the groundwater reservoir area of the LuYang is about 11.8 million m~3 in the case of no underground dam and no seawater intrusion;During the construction of the underground dam,the annual water supply of the underground reservoir is about 15 million m~3,the lowest water level of the underground reservoir is about-12m,and the seawater intrusion will not occur;when simulating the construction of the underground dam,according to the forecast water requirement of the economic development rate of the LuYang,the underground reservoir meets the need of the water demand after 20 years,and a large area of groundwater funnel will be found in the area,which is difficult to maintain the sustainable water supply capacity of the underground reservoir;considering the recovery balance of the underground reservoir,and collecting the rainfall surface runoff of LuYang as the artificial recharge water source of the underground reservoir in the case of no outward water source,in the next 20 years,the Lu Yang underground reservoir can meet the annual maximum water consumption of living,ecological,agricultural and industrial use for 43.57 million m~3,At the same time,this scheme is recommended as an underground reservoir water storage and recovery scheme.The research results can be used as reference for the development and comprehensive utilization planning of Pingtan water resources,and also for the construction of underground reservoirs in our coastal islands.