MODELLING OF SALT WATER ENTRY INTO A PUMPED WELL

Abstract

A numerical model for simulation of convective salt water movement and entry into pumped well in coastal aquifers, is presented. The method of characteristics is used to solve the convective solute transport equation. The necessary velocity distribution is arrived by solving the two-dimensional axi-symmetric ground water flow equation using iterative alternating direction implicit method. The model eliminates many of the assumptions made in the analyti-cal solutions available so far. During the operation of the model it was inferred that the adopted alternating direction iterative procedure for simulation of piezometric heads is not efficient for solving two-dimensional axi-symmetric flow problems. The model was able to estimate the salt water concentration in the pumped water at discrete time intervals. Apart from this, it also yielded the volume of salt water lifted from the fresh-water-salt water interface as a function of time.