Groundwater Recharge,Discharge,Runoff Characteristics And Hydrochemical Evolution Of Hamatong River Basin In Sanjiang Plain

Hamatong River Basin located in the southern end of Sanjiang Plain,is an important grain producing areas of Baoqing County.With the rapid development of industry,agriculture and the increasing demend for domestic water,industrial water,agricultural irrigation water,groundwater has emerged water level decline,deterioration of water and other groundwater issues.In this paper,we choose the Hamatong river basin as the research area.Combining the hydrogeological condition analysis and isotopes(¹⁸O,D,³H,¹⁴C)to try to solve the problems of the recharge sources of surface and groundwater,the age of groundwater and the rate of renewable.Using the correlation analysis,factor analysis,ion ratio method and reverse geochemical simulation technique to identify the source and formation evolution of water chemical components in the basinThe results show that the river is mainly supplied by the precipitation and the lateral runoff.The river is weakly connected with the groundwater in the plain.The Quaternary pore water is recharged by the precipitation and lateral runoff,mainly excretion by the lateral runoff and artificial mining.The fissure pore water is recharged by the fracture water.Below the 30 m depth of groundwater,the ages of The Quaternary pore water are about 3000-5000 years.Less than 30 m,the ages is 5-250 a.The annual renewable rate of the Quaternary water in the six points of 853 farm is 0.72⁷.2%/a.It is about 0.34⁰.50%/a in the six points of 852 farm.The ages of The Tertiary pore water are about 7000 to 20000 years.The annual renewable rate of the fissure pore water in the piedmont area is higher than the platform and plain area,and it is about 0.035%/a.In the platform area that is about 0.005⁰.016%/a.In the plain area that is 0.001⁰.003%/a.In the study area,the chemical types of the groundwater are mainly HCO₃-Ca,HCO₃-Ca·Mg,HCO₃-Ca·Mg·Na,HCO₃-Na·Ca·Mg,HCO₃-Na·Ca and HCO₃-Na,which shows a significant zoning law from the mountain to the low plain area.the chemical types are from HCO₃-Ca,HCO₃-Ca · Mg to HCO₃-Na · Ca · Mg,HCO₃-Na·Ca.The functions of control the formation of water chemical composition are mainly CO₂ ? calcium feldspar,albite,potassium feldspar,calcite,biotite dissolution,Ca-Na ion exchange,montmorillonite,chlorite precipitation and human agricultural activities.In all,the results can provide reference for the rational exploitation,protection and protection of groundwater in the Basin.