The Investigation Of Underground Reservoir Construction In The Excess Exploited Funnel Area

Excess exploited funnel Area in plain is the area where the groundwater's exploitation and retirement out of order. Which is caused by spiral downward of groundwater level and expanding of funnel area because of longtime and excessive mining of ground water. Series of environmental geologic problems were created, such as land subsidence, ground depression, ground fissure and groundwater pollution, and so on. These problems caused demand and supply contradiction of water resources in funnel area was prominent and environmental problems frequent. So they retarded imposed social and economic development and made the development of social and economic disturbing. Building the groundwater reservoir is the effective way to solve these problems. Because saving water in ground aquifer and having a lot of advantages which surface reservoir without, groundwater reservoir became hot off the press of scholars home and abroad. Now, many countries are executing artificial recharge of ground water, to resolve environment problems caused by shortage of water resources. Groundwater storage engineering came into effect in our country from 1980's. There are many successful examples. And the types of groundwater reservoirs as Tablel-1. According to Tablel-1, we can infer, at present, the groundwater reservoirs built mostly located in mountain interval and valley, strand plain and alluvial-proluvial fan of mountain area. The storehouse area built mostly use natural aquifer as water space. Excess exploited, which is the caused by longtime overdraft, are not yet in-depth studied.Excess exploited funnel area mostly are gently topography and has rather coated aquifer. This aquifer mostly has tremendous unwavering space after excessive mining. Funnels' formations have changed native flow direction of groundwater, made groundwater focus on the flow of funnel center district, so the dynamic condition of groundwater is fit to taking supply measures. Closure conditions around funnel area are good. The bottom of aquifer has acquitted. And the center hydraulic gradients of the funnel area are low, which can restrict runoff water to external flow. So these area have good condition of storage water. If having a scientific and reasonable groundwater recharge engineering, this area can build a packed funnel groundwater reservoir.This study takes the Jining～Wenshang excess exploited funnel area as example, which is the large funnel area of porous phreatic aquifer in plain. The author gathers a lot of data, synthesizes predecessors research results, demonstrates the feasibility of building a packed funnel groundwater reservoir in this area from three aspects, which are necessity and condition of building groundwater reservoir, and benefits after building groundwater reservoir. Groundwater level history of study area back and forth repletion was visual simulated basing on Visual Modflow, according to pumping well and observation well datas existing. And reservoir capacity was calculated basing on Surfer software. After argumentation, this paper comes to a conclusion that Jining～Wenshang excess exploited funnel area enjoys advantages of building groundwater reservoir and proves up to artificial recharge of ground water. So this area is fit to buiding a packed funnel groundwater reservoir. According to systematically analysis and study, this paper come to a conclusion: buiding packed funnel groundwater reservoirs in the large funnel area of porous phreatic aquifer in plain can improve water shortage and eco-environmental problems, and gives advices having actual value for this area's ecological environment and sustainable economic development.