A Study Of Variation Characteristics And Control Index Of Shallow Groundwater Level In Guangping County,Hebei Province

Located in Handan City,the Guangping County is a resource-based water-deficient area.The per capita water resources account for only 1.4% of the national average.The surface water resources in Guangping County are scarce,and groundwater resources have become the main water use for the local social and economic development.In recent years,over-exploitation of groundwater has caused geological disasters and groundwater environmental pollution.It has an impact on the social economy and people's life.The determination of shallow groundwater level control indicators can provide a scientific basis for rational exploitation of groundwater and efficient management of groundwater resources.This paper analyzes the characteristics of shallow groundwater level changes and uses the Pearson correlation analysis method to determine the main factors affecting the shallow groundwater level changes.On this basis,the multiple linear regression analysis method is used to determine the shallow groundwater level control index.The main results of the research are as follows:1.The analysis of the dynamic characteristics of the shallow groundwater level shows that the water level changes during the year with obvious rising and falling periods.Based on the inverse distance in ArcGis10.4 software,the weighting method(IDW)depict the interannual and spatial variation characteristics of the groundwater depth in different years.The results show that from 1998 to 2017,the shallow groundwater level in Guangping County has been declining.In2014,Guangping County carried out comprehensive groundwater overexploitation.After the treatment,the water level decline has slowed down;spatially,the shallow groundwater depth in Guangping County generally shows a gradually increasing from the northeast to the southwest,with large spatial regional differences.From 2006 to 2017,the water level in most areas of the county was relatively stable,and the groundwater table in the north of Pinggudian Town and the east of Guangping Town increased,and the annual average water level change in some areas is greater than 0.5m.The groundwater level in the northwestern part of Guangping Town and the southern part of Shengying Town has fallen sharply,with an average annual rate of decline greater than 0.4m.2.By collecting a series of data on precipitation,shallow groundwater extraction,well irrigation replenishment,and canal irrigation field infiltration replenishment,this study analyzes the dynamic change properties of the four contributing factors and uses the Pearson correlation analysis method of the statistical analysis software SPSS.Correlation analysis of buried depth shows that shallow groundwater extraction has the most obvious impact on groundwater level,followed by precipitation.Well irrigation return replenishment and canal irrigation field infiltration replenishment have no significant impact on groundwater level.3.Controlling the shallow groundwater extraction,and combined with the shallow groundwater level drop control rate,the multiple linear regression analysis method to acquire the lower limit control indices of each representative monitoring well burial depth in different years in 2030.Then inverse distance weighting method(IDW)is applied to determine Control indicators for the lower limit of shallow groundwater depth in all townships: By 2030,all townships in Guangping County will become areas where groundwater level is basically stable or water level rises.In 2030,there are three hydrological years of high and low levels.The deep average does not change much.4.Using the inverse distance weighting method(IDW)to determine the lower limit control index of the shallow groundwater level in different hydrological years in Guangping County in2030: the lower limit control index of the buried depth is 31.69-34.66 m.By 2030,the shallow groundwater level will be at the basic level stable state.