Study On Numerical Simulation Of Groundwater Flow In The Upper Reaches Of Xiaoluan River In Chengde,Hebei Province

As a very important natural resource for human life and production,and groundwater is an important basis for human survival and social development.The ecological environment of Xiaoluan River basin upstream region is fragile.With the rapid growth of economy and population,the contradiction between supply and demand of water resources is gradually becoming prominent.So,it is of great practical significance to find out the hydrogeological conditions,groundwater occurrence,distribution and variation rules in this region,and to provide a basis for the development,utilization and protection of groundwater,so as to ensure the sustainable utilization of groundwater in this region.This paper is based on the “Chengde District Hydrogeological Survey Project” of the China Geological Environment Monitoring Institute Project Fund.Through the field actual hydrogeology survey,pumping test,aviation remote sensing method,the hydrogeological parameters are used to establish the conceptual model of hydrogeology in the study area.Based on the collected data of meteorology,hydrology and groundwater exploitation,GMS software is used to set up the source and sink items in the study area and establish the mathematical model of groundwater flow in the study area.The main conclusions are shown as following:(1)The model was verified by using the observation hole data of groundwater levels measured from 2016 to 2018.It can be seen from the fitting of the observation hole that the simulation results of the mathematical model are consistent with the variation characteristics of the actual groundwater level in the research area,and the reliability of the simulation is relatively high.(2)The groundwater balance results from the model calculation results show that the recharge source of groundwater aquifers in the simulated area is mainly rainfall infiltration,the discharge volume is mainly evaporative discharge and the second is lateral runoff discharge.The total recharge is less than the discharge.So,the regional groundwater resources in the simulation period are in a negative equilibrium state,and the regional groundwater level shows a downward trend,The average annual drop height is around 0.01 m.(3)Through the establishment of the prediction model,the production volume of two new mining wells in Shenxiandong and Qianyuanshanzi was designed.When the mining yield of No.1mining well in Shenxiandong area is 300m3 /d,and the mining yield of No.2 mining well in Qianyuanshanzi area is 400m3 /d,After 10 years,the degree of groundwater level decline meets the constraints of groundwater exploitation.The distribution of groundwater flow field in the study area has not changed much and will not have a negative impact on the lives of residents in the area.