Field monitoring and numerical simulation of seawater and brine water intrusion to groundwater in the coastal area of Laizhou bay, China

Abstract:

In geological time, seawater intruded groundwater many times in the coastal area of Laizhou bay, china, which caused freshwater and brine water interbedded each other in the aquifers. In the last two decades, massive exploitation of fresh groundwater and brine water has significantly increased seawater intrusion and strengthened mixture of brine water and freshwater in the coastal area, which threatens local groundwater resources and severely impacts local ecological geo-environment. The seawater and brine water intrusion in the area has been continuously monitored over a long period of time. In this study, the seawater and brine water intrusion to fresh groundwater is estimated according to the reasonable monitoring indexes. Groundwater circulation is characterized through hydrogeochemical and isotope analysis. Meanwhile, the seawater and brine water intrusion processes from past to future have been numerically simulated. The study results indicate the current exploitation scheme will significantly decrease fresh groundwater resources in twenty years.

Key words: Seawater and brine water intrusion; Continuous field monitoring; Hydrochemical analysis; Isotope analysis; Numerical modeling