Analysis And Prediction Of Groundwater Level Variation In Shijiazhuang Plain

For the long time,with the rapid development of China's economy,water resources are becoming increasingly scarce,especially in North china.The plain area of Shijiazhuang is a typical area of over exploitation of groundwater resources in North China plain.Due to the long-term over exploitation of groundwater,groundwater supply and drainage lose balance,the groundwater level in the plain decreases rapidly that made a number of groundwater level drawdown funnels ware formed in the region which become larger gradually in the last few decades.The formation of groundwater drawdown funnel has caused geological problems such as ground fissures and collapses.According to the situation that the groundwater level is decreasing and the groundwater funnel is increasing in Shijiazhuang,Shijiazhuang has carried out the comprehensive management of groundwater overdraft,there are two main ways of governance: The first is to strengthen the construction of supporting projects of the south to North Water Diversion Project,and take Full use of water from the south to North Water Diversion Project to replace groundwater;The second is implementing the project to reduce groundwater extraction,strengthen water saving project construction by structural water saving,engineering water saving,agricultural water-saving to improve the efficiency and benefit of industrial and agricultural water use.In this paper,the observation data of groundwater depth,the quantity of groundwater exploitation,the quantity of rainfall and DGP in the plain area of Shijiazhuang in 1980-2015 are used to analyze the change characteristics of groundwater depth in Shijiazhuang plain area and its relationship with the influencing factors.The prediction model of groundwater depth in Shijiazhuang plain area is constructed by multiple linear regression analysis and genetic BP neural network algorithm and the prediction of groundwater level in Shijiazhuang plain is carried out.After comparing the simulation results of the two forecasting models,the genetic BP neural network prediction model was selected to predict the average groundwater depth in Shijiazhuang plain in 2016-2021 in two cases: the comprehensive management of groundwater overdraft is carried out in Shijiazhuang and the comprehensive management of groundwater overdraft is not carried out in Shijiazhuang.There is a great difference in the speed and magnitude of groundwater level decline in different areas of Shijiazhuang plain,the groundwater level decreases smaller in the western,northern,northeastern and a small part in the southwest region and decreases larger in the central,southern and eastern regions,the area with the most severe decline is the southeast.With the comprehensive management of groundwater overdraft work has not been carried out compared,the comprehensive treatment of groundwater overdraft in Shijiazhuang can effectively reduce the speed of groundwater level decline and will be able to achieve better governance results in the next period of time.