Abstract
This paper studies the degree of chemical pollution of groundwater in the Pearl River Basin and the chemical evolution mechanism of water body. Then it analyzes the change trend of discharge, balance, total dissolved solids (TDS), water ion concentration and other parameters of groundwater in the basin in the past 20 years, as well as discusses the impact of chemical evolution process of groundwater on water cycle. According to the study, the groundwater storage volume in the Pearl River Basin has begun to decrease year by year because of the excessive exploitation of groundwater caused by increased human activities, industrial and agricultural water consumption. When the cover depth of groundwater is great, the external replenishment of groundwater gradually reduces with salt, minerals and chemical pollutants continuously accumulating, which will lead to the gradual increase of TDS of groundwater. Seasonal changes have a little impact on the chemical evolution of groundwater. Groundwater recharge area mainly contains Ca2+-Na+-HCO3- that will be converted to Na+-K+- HCO3--Cl- in discharge area. The chemicals contained in groundwater are mainly related to geotechnical types, environmental conditions and various chemical reactions. The study on the chemical characteristics and evolution rule of groundwater can provide theoretical reference for the rational and effective use of water resources.
