Research on hydrological characteristics of underground salty water and the sources of seawater intrusion in Guangzhou
To explore the sources of seawater intrusion in Guangzhou City,the ion characteristics and hydrogen and oxygen isotope characteristics,the correlation and distribution patterns between Cl-and Br-of groundwater samples in Guangzhou were analyzed and studied,and a comprehensive judgments was made based on regional hydrogeological conditions.The strong correlation between ρ(Cl-)and ρ(Sr2+)preliminarily proved that the cause of groundwater salinization was modern seawater intrusion.By comparing the ρ(Sr2+)/ρ(Cl-)and ρ(Sr2+)/ρ(Ca2+)of groundwater and seawater samples,it was determined that Sr2+could also originate from ion exchange between water and rock.Cluster analysis results were used to group groundwater at different locations,and the grouping results were similar to the ion characteristic grouping results,which provided more evidence for determining the cause of groundwater salinization.By comparing the hydrogen and oxygen isotope characteristics of groundwater and seawater,the gradual transition of δD and δ18O towards seawater indicated the source of groundwater recharge and the trend of groundwater salinization in Guangzhou.The positive correlation between the values of δD and δ18O and the mass concentration of Cl-also proved that the groundwater in the seawater intrusion area of Guangzhou was contaminated by seawater.
seawater intrusionstrontiumCl ion contentD～18O isotopes
NETL
NSTL
万方数据
