Evaluation of groundwater resource forecast in Yancheng

Yancheng is a developing coastal city in the north of Jiangsu Province. The aquifers, which can supply groundwater, are classified as middle Pleistocene confined aquiferⅡ, lower Pleistocene confined aquiferⅢ, middle and upper Pliocene confined aquiferlV in the city. These aquifers are divided by the clays which are of weak permeability, but there are intensively hydraulic relation among these aquifers. Based on the validation and verifying of this model, and the request of geology environment control such as land subsidence, salty water infiltration and so on, this paper uses three dimension numerical model to plan and forecast the quantity of groundwater exploitation and the optimal exploitation pattern in every aquifer when the lowest groundwater levels in confined aquiferⅡ, confined aquiferⅢ, and confined aquiferⅣ rise to -20m, -30m, and -40m again year after year respectively by the end of Dec 2004, and forecast the quantity of groundwater exploitation when the groundwater level depression cone in every aquifer trends to reach stabilization.