Modeling preferential zone-regulated freshwater-saltwater mixing zone
The coastal aquifer or “subterranean estuary” (Moore 1999) is defined as the coastal regions where ground water derived from land drainage measurably dilutes sea water that has invaded the aquifer through a free connection to the sea. The groundwater level (hydraulic head or water table) in coastal aquifer fluctuates with time in response to the water level fluctuations of the tidal water body (sea or river/stream). Since 1950s, the theoretical research and field investigation of groundwater flow and salinity distribution in the coastal aquifer systems have been conducted by many hydrogeologists (e.g., Nielsen 1990, Kim et al. 2006, Xia et al. 2007, Brovelli et al. 2007, Li & Boufadel 2010).