Study On Dynamic Prediction Of Groundwater In Yancheng City

YanCheng City is in the Northern Jiangsu Plain,the area of city is about 17 thousand Square kilometer.It's a very important coastal city in Jiangsu Plain.The exploitation of aquifers in the region over the years since the new century has led to a continuous decline in the groundwater level in the study area,resulting in a severe groundwater fall culvert and a significant impact on the local geological and ecological environment.The period about groundwater dynamic simulation of Yancheng City is determined from March 2005 to March the following year for a whole year,using the data collected by the regional groundwater level,combining with drilling data,regional lithology,preliminary draw with the parameters of aquifer,the study area of initial water level,boundary conditions and so on,so to build a three-dimensional hydrogeological model.The model consists of a total of nine layers,including a layer of diving aquifers and four layers of confined aquifer,due to the existence of a weak permeable layer between each layer,so establish a groundwater system consisting of a 9-layer aquifer.The simulated flow field and the actual flow field are verified by comparing the measured March 2006 data.After adjustment,the satisfaction is consistent with the flow direction of the actual flow field,and the error between the water level and the actual data obtained from the important monitoring wells is within the required range.Calculating the water balance of the whole system,it is concluded that the area is basically in line with the requirement of water balance: the amount of water received in the system is about 4.30×109m3,the annual excretion of water is 4.48×109m3,and the annual equilibrium is about-1.88×108m3,in negative balance.Based on the present situation and development of Yancheng development plan,groundwater exploitation planning and water saving measures,the paper puts forward the scheme of mining groundwater in different situations in the short-term future to 2025,simulation.The results show that the water level of the diving water is increased to-1.03 m under the first scheme when the distribution of the well is roughly unchanged.The aquifer in the second program forms a new fall funnel,Down to-1.5 m;indicating that the aquifer is susceptible to changes in the amount of exploitation.In the case of Schemes 1 and 2,the number of culmers in the overall flow field has not changed much.The change mainly depends on the rise or fall of the water level of the descending funnel in some areas.