Combining Isotope and Hydrogeochemistry Methods to Study the Seawater Intrusion: A Case Study in Longkou City, Shandong Province, China

In order to study hydrogeochemical effect in the process of seawater intrusion (SI), and provide scientific basis for comprehensive management water resources ecological restoration, Longkou city Shandong province China was taken as an example this study. Based on observed data, traditional hydrogeochemistry methods hydrochemistry analysis, correlation principal component reverse geochemical simulation firstly comprehensively combined with stable isotope tracing city, is first use method SI area. The results showed Cl− had high Na+, Mg2+, K+. hydrochemical types groundwater were mainly HCO3.Cl-Na.Ca, HCO3.Cl-Ca, showing evolution HCO3-Ca HCO3.Cl-Na Cl-Na from inland coastline. Stable isotopes analysis δ2H, δ18O 87Sr/86Sr indicated main source atmospheric precipitation. degree strongest at junction west north coast zones, values δ2H δ18O. Sr2+ concentration groundwater–rock interactions. process, mixing fresh took place first, then different degrees cation exchange mineral dissolution sedimentation occurred. Results dolomite quartz precipitated, negative migrated masses 1.38 × 10−3 1.08 10−5 mol/L Path 1, respectively, where calcite, halite, gypsum dissolved positive 2.89 10−3, 3.52 4.66 10−4 mol/L, while precipitated 2. On 3, dolomite, gypsum, dissolved, calcite a mass 1.77 mol/L.