Author(s): Kei Nakagawa; Kazuro Momii; Roger Luyun Jr
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Keywords: Seawater intrusion; Injection well; Cutoff wall
Abstract: The application of artificial recharge by injection and the construction of subsurface barriers are among strategies proposed to control the impact of global sea level rise on coastal groundwater systems. In this paper, laboratory-scale experiments and numerical simulations using SEAWAT were performed to determine the effective locations of injection recharge application and cutoff wall installation. Experimental results for recharge injected upstream of the toe of saltwater intrusion wedge achieved a 6%repulsion of the saltwater wedge for the case of 20%increment of original freshwater discharge, and 12%repulsion for the 40%increment. Simulations with different injection locations revealed that more effective saltwater repulsion is achieved when injection recharge is applied near the toe of the saltwater wedge. Experimental results for cutoff walls partially penetrating the aquifer showed that more effective saltwater repulsion is achieved with deeper wall penetration. Simulations with different wall locations and depth of penetrations showed that more effective saltwater repulsion is achieved with cutoff walls installed closer to the coast. The reverse is true when the wall is installed farther inland as this cause increased saltwater intrusion.
Year: 2010