Numerical Analysis of Groundwater Density Flow with Boundary Element Method and the Effect of Impervious Wall against Salt Water Intrusion

Abstract

It has been reported that the salt groundwater invade inland and the aquifers become contaminated with salt as a result of over discharges of fresh groundwater by the wells in coastal areas, and the drawdown of groundwater level by the shortage of precipitation. Consequently, it is significant to calculate the movement of salt groundwater.
In the present paper, for the study of preventation of salt water intrusion, the author discusses the formulation for a numerical analysis of the groundwater density flow with the boundary element method. Numerical analysis was carried out for the following two cases, (1) the steady problem in -unconfined groundwater, (2) the unsteady problem in confined groundwater.
The stability of unsteady numerical solution was obtained to calculate the real part of eigen values every time step. About the behavior of fresh and salt water interface, the numerical solutions show good agreement with the experimental results.
Also, the author estimated the effect of the impervious wall for countermeasure against salt water intrusion.