A COMPATIBLE SINGLE-PHASE 2-PHASE NUMERICAL-MODEL .2. APPLICATION TO A COASTAL AQUIFER IN MEXICO

The application of a numerical model to a coastal aquifer is presented including the simulation of single‐phase and two‐phase fluid flow. The single‐phase part of the model solves the diffusivity equation and helps to identify certain parameters of the aquifer and to simulate the flow field (fresh water) under different conditions. The two‐phase part of the model solves the partial differential equations describing the motion of salt water and fresh water separated by a sharp interface. The model was calibrated using the observed piezometry of the aquifer for the fresh‐water flow field. Simulations were made for both steady‐and unsteady‐state conditions to establish the position and movement of the interface under different schemes of pumping. Results show that the model reproduces very accurately the flow field of fresh water. It identifies the potential salt‐water intrusion (upconing) into some of the pumping wells, thus helping in the identification of optimal pumping schemes. Copyright © 1990, Wiley Blackwell. All rights reserved