Evolution Characteristics And Cause Analysis Of Groundwater Depression Funnel In Ningbailong,Hebei Plain

Due to the excessive exploitation of groundwater in Hebei Plain,many underground water fall funnels have been formed.The harm of underground water fall funnels has aroused the attention of the society.However,the research on the funnels has started recently,and how the evolution trend of the funnels is developing,how to effectively manage the funnel,how to balance groundwater exploitation and economic development,these are the issues we need to study.Based on the data of Hydrologic Dynamic monitoring in the region of Ningbailong funnel in the past 20 years and using the methods of groundwater dynamics and Statistics,this paper discusses the formation and evolution of the groundwater funnel in the basin,the evolution trend of the funnel is summarized from both horizontal and Vertical Directions,and the development of the funnel is divided into three stages: The straight development stage,the stable development stage and the gradual recovery stage,it is concluded that the funnel evolution has the characteristics of horizontal and vertical inhomogeneity and mobility,and the impact factors of funnel formation and change are identified,the six factors,i.e.rainfall infiltration recharge,evaporation,extraction,GDP,population and irrigation regression infiltration,are analyzed.The results show that extraction is the main factor affecting groundwater level dynamics The principal component analysis is used to reduce the dimension of the influencing factors and to explore the main driving factors of the funnel in this area A multivariate time series CAR model is used to model the variation of Ningbailong depression funnel.The model is used to predict and analyze the changing trend of the Ningbailong depression cone in the next five years and the next ten years,which provides a reference for the control of groundwater depression in Hebei Province.