Study On The Spatio-temporal Dynamics And The Influencing Factors Of Groundwater Depth In The Plain Area Of Fuyang River Basin

Fuyang River basin plain area is the south of Hebei Province the largest shallow funnel distribution area.A systematic analysis of the dynamic characteristics of groundwater level in this area,and a thorough study of the spatio-temporal variation of groundwater depth and its influencing factors will provide a scientific basis for the realization of "The springs flow again in Baiquan basin" in this area,which has important practical significance for the protection of groundwater and ecological environment in this area.This paper systematically analyzes the dynamic types and characteristics of the groundwater level in the area by collecting and sorting out previous research results,physical geography,geological conditions,hydrogeological conditions,groundwater monitoring station data,and rainfall data.The dynamic period of groundwater level at typical locations was identified by using autocorrelation coefficient method.Using mathematical statistics method and geostatistics method,the spatial and temporal variation characteristics of groundwater depth in the area are discussed.The detection model of influencing factors of temporal and spatial variation of shallow groundwater depth was established by using geographic detector,the weight ratio and interaction relationship between influencing factors were determined,and the restoration measures of water level in the area were proposed,which provided the basis for groundwater management and protection scheme in the area.The main conclusions are as follows:(1)Dynamic types and distribution of shallow and deep groundwater.The dynamic types of shallow groundwater can be divided into lateral recharge-exploitation and rainfall infiltration-exploitation.The lateral recharge-exploitation type is mainly distributed in the sloping plain of fan-edge,while the precipitation infiltration-exploitation type is mainly distributed in the area with large and relatively concentrated groundwater production.The dynamic types of deep groundwater are mainly runoff-exploitation type and over-flow-exploitation type,and runoff-exploitation type is mainly distributed in piedmont plain area.The overflow-mining type is mainly distributed in the middle and east of the plain area.(2)Extreme depth distribution and annual fluctuation characteristics of shallow and deep groundwater.According to the statistical analysis of the extreme value and variation coefficient of groundwater burial depth in the area from 2016 to 2018,the shallow groundwater burial depth in the area is the largest from April to June each year,and the smallest in January.The relatively strong fluctuation period of shallow groundwater is mainly concentrated in March to June every year,and the stable period is mainly distributed in February and September every year.The depth of deep groundwater is maximum in AprilJune and minimum in December.The deep groundwater fluctuates strongly in March and June each year,and the stable period is mainly in February.(3)Spatial distribution characteristics of shallow and deep groundwater depth.The depth of shallow groundwater in the area is radially distributed around the Ning-Bo-Long Funnel.The depth of water level in the western area is relatively shallow,and the overall distribution characteristics are shallow in the southwest area and deep in the northeast area.For the deep groundwater,Nanhe and Renze in the southeast of the study area have the shallowest groundwater depth.Northwest Baixiang,Ning Jin area buried deep;Longyao area is in the transition zone of high and low buried depth,and the water level buried depth is banded.The overall distribution characteristics are shallow in the southeast and deep in the northwest.(4)Variation of groundwater depth in different periods.Using Arc GIS software,Kriging interpolation was used to analyze the variation of groundwater depth in each period.The shallow groundwater depth fluctuation in the area mainly included Xingtai and Neiqiu area in the southwest,the central area of Ning-Bo-Long Funnel in the middle,and Ningjin area in the northeast.The fluctuation of deep groundwater depth is mainly distributed in the east of Longyao.(5)Research on the detection model of influencing factors of temporal and spatial variation of shallow groundwater depth based on geographic detector.The factor detection and interactive detection module of the geographic detector tool was used to quantitatively analyze the influencing factors of the spatial and temporal variation of shallow groundwater depth in the study area.The infiltration coefficient and water supply degree had the most significant influence on the spatial and temporal variation of shallow groundwater depth.The interaction between population density,mining intensity and infiltration coefficient has a stronger influence on the spatial and temporal variation of shallow groundwater depth than other influencing factors.