Simulation And Dynamic Analysis Of Groundwater Drop Funnel Management And Control In Harbin After Dadingzishan Reservoir Is Impounded

Since the 1970 s,due to long-term over-exploitation in Harbin City,groundwater overexploitation has been severe in some areas,and the groundwater level has continued to drop,forming a groundwater fall funnel,which has caused a series of ecological and environmental geological problems.The 9 districts of Harbin(Jiangbei,Daoli,Nangang,Xiangfang,Pingfang,Daowai,Hulan,Acheng and Shuangcheng),which are located in a cold area and have typical drop funnel characteristics,are used as the groundwater overexploitation area Analysis area for numerical simulation.Take Harbin City's Jiangnan Five Districts(Nangang,Xiangfang,Pingfang,Daowai and Songnan Part of Daoli District)as the calculation area.On this basis,the following work is carried out.(1)This paper summarizes the concept,classification and main hazards of groundwater depression funnel,and sorts out some evaluation and analysis methods of groundwater.Based on this,numerical method is selected as the main analysis and evaluation method of groundwater depression funnel in calculation area.(2)The physical geographical background(geographical location and traffic,topography and meteorology)and socio-economic characteristics of the analysis area were sorted out and analyzed.Based on the investigation and analysis of the basic parameters of Dadingzishan reservoir located 46 km downstream of Harbin section of Songhua River,the influence on the water level of Harbin section of Songhua River is identified.(3)Select 3 typical groundwater monitoring wells(No.ZD-1,ZD-2 and ZD-3)in the calculation area,and analyze the monthly groundwater level dynamic changes and annual groundwater level of typical wells according to groundwater level monitoring data.Data processing and result analysis are carried out on the dynamic changes of water level and the dynamic changes of water level during high(low)water period.The results show that:(1)A method for judging the state of groundwater exploitation based on water level and water volume is given.According to different judgment results,the state of groundwater exploitation is divided into five states: severe overexploitation,overexploitation,normal mining,immersion,and serious Submerged,and numbered each state in order to trigger the corresponding groundwater dual-control management plan;(2)The groundwater level of the Youyi Palace monitoring well(ZD-1)in Daoli District is supported by the water level of the Songhua River and maintained throughout the year It is close to the normal water level of 116 m after the impoundment of Songhua River Dadingzishan Reservoir.The monitoring well(ZD-2)of the preparation plant of the Harbin Pharmaceutical General Plant in Nangang District and the monitoring well(ZD-3)of Shuangyushu Village,Liming Township,Xiangfang District,are affected by precipitation and artificial exploitation.The international change is also large,showing an upward trend.(3)The change of groundwater dynamics in loose rock pores is directly affected by atmospheric precipitation.After precipitation,the groundwater level rises rapidly,and at the same time,the river water level rises and the groundwater level rises.The water level is highest from July to September each year,which is the period of high water.From mid-to-late October to early May of the following year,the groundwater level drops,which is a dry season.Loose rock pore confined water and weakly confined water are mainly recharged by atmospheric precipitation infiltration and lateral runoff.Groundwater dynamics are mainly restricted by hydrological and meteorological factors.The recharge of atmospheric precipitation has a lag period of 2-3 months,that is,every year.The water level is highest from September to October.