Study On The Groundwater Resource And Groundwater Circulation In Caofeidian

Planned from 1992, Caofeidian project is started in the round in 2002. The groundwater has been playing an important role in the construction of Caofeidian. It's necessary to reasonably assess the water resources to achieve coordinated development of economy-society and environment-energy. The study of groundwter storage and distribution has an deep leading meaning to groundwater resource planning. In addation, cycling model of groundwater and the groundwater amount of resources, which are the foundation of groundwater resource evaluation, can guide the exploitation and utilization of groundwater and fix the exploitation location and allowable yield. In the purpose we have showed above, the aim of this paper is to build the cycling model of groundwater in Caofeidian, establish the region groundwater flow numerical model and ascertain the region groundwater amount of resources to provide basis for groundwater resource development and utilization.This paper estimates the groundwater amount of resources by divide research area into 2 layers. The shallow groundwater recharge is 83430.78×10~4m~3/a, which is mainly from precipitation, secondarily from lateral inflow, infiltration recharge of irrigation water and lekage of surface water. The shallow groundwater discharge is 86122.38×10~4m~3/a, which includes exploitation, evaporation, leakge and lateral inflow discharge. The deep groundwater recharge is 23994.92×10~4m~3/a, which is mainly from lateral inflow, infiltration and lekage of surface water. The deep groundwater discharge is 23394.62×10~4m~3/a, which is mainly from exploitation, secondarily from lateral inflow discharge.To intuitively reveal groundwater cycle characteristics and controlling factors, two dimensional numerical simulation is employed on "A-A section". The groundwater flow direct from the Yanshan piedmont to the Bohai Sea. There is a descend funnel in the shallow junction of salt and fresh water by the exploitation and groundwater divide between from Tanghai and seacoast. The head of upper of deep groundwater descends and lower groundwater directs from the piedmont to the Sea. In vertical direction, there is apparent interchange between groundwater in different layers and depth. Geographic and geomorphic conditions and the structure of aquifer are background factors which can control groundwater flow in section. Overexploitation of groundwater has a great influence on the occurrence of groundwater flow systems and the direction and velocity of groundwate flow. In "A-A section", the main discharge way are evaporation and exploitation of shallow groundwater in local circulation system, exploitation of deep groundwater in middle circulation system and discharging to the sea in the region circulation system. The recharge of lateral inflow in piedmont most concentrat on the local and middle circulation system, relatively little in the region circulation system. Deep groundwater leakage recharge a little to shallow groundwater. As shown in the result of model, seawater intrusion haven't formed under exsiting exploitation.By recognize and check the groundwater flow numerical model in Caofeidian, the water levet fitting error less than 2m make up 95.63%, the simulation stream field is consistent with actual stream field and the simulation water budget is similar to the result of estimated groundwater amount of resources. The model is accurate and can be applied to predict.