Simulation of Water Infiltration Process into a Porous Unsaturated Soil: Application on Tangier’s Bay Region-Morocco

Abstract

The study is focused on numerical simulation of the infiltration process of polluted water originating from a wadi into the unsaturated soil of a bay. This study addresses the linkage between unsaturated zone and groundwater and it discusses the ability of the unsaturated soil to receive the water dried at once by the wadi and the bay. The simulation requires a number of trials, something that is experimentally expensive and sometimes impossible. The infiltration process is governed by the Richard’s equation. To solve this later, the knowledge of soil water properties such as pressure head, water content and hydraulic conductivity is needed. Hence, the water retention and unsaturated hydraulic conductivity curves near saturation have been established for a range of water content going from h = (− 25 m; 25 m) to h = (− 175 m; 175 m). These curves are obtained using the simulating computer program Hydrus 2D/3D. Numerical results have been calibrated with the Musy and Soutter (Physique du sol (soil physics), Universite de Technologie Compiegne, Lausanne, 1991) type relationships. It has been explained that the infiltration process from the saturated zones to the unsaturated zone is relatively slow depending on the soil structure.