FRESH AND SALTWATER MOVEMENT AFTER INSTALLATION OF CUT-OFF WALL IN CONFINED AQUIFER

Abstract

To understand saltwater movement in the coastal confined aquifers, we performed laboratory experiments on saltwater in a confined aquifer and numerical experiments on effects of cut-off wall height and transversal dispersivity on the repulsion of saltwater wedge. Experimental results confirmed that saltwater wedge showed repulsion and numerical results showed that most effective wall height for repulsion was saltwater height at the location where the cut-off wall was installed. In the residual saltwater wedge, circulation flow occurred and fresh water discharge flowing along outer part of this circulation transported salt and finally flushed this out. Because that the direction of saltwater wedge to fresh water flow is transverse; the appropriate transversal dispersivity should be given when the saltwater removal with cut-off wall is numerically evaluated. Key