Assessment of water resources in fractured rocks by remote sensing and GIS methods: case study of the semi-mountainous region of western Cote d'lvoire

摘要

Managing water resources in a vulnerable environment is a current issue. The western semi-mountainous region of Cote d'Ivoire is under a heavy human pressure due to a high birth rate (5%), a soaring influx of war refugees from the neighbouring countries of Liberia, Guinea and Sierra Leone, and finally an increase in touristic, agricultural, and pastoral activities. Unfortunately, the irregularities of seasons and the climatic fluctuations over the last three decades have caused a decrease in precipitation. Hence, the spatial distribution and the sustainable management of the water resources in this part of the country is a major concern to both scientists and decision makers. A quantitative assessment of the available water resources has been initiated at the Centre Universitaire de Recherche et d'Application en Teledetection (CURAT, the University Research Center in Applied Remote Sensing) at the University of Cocody. This work aims to improve the knowledge on aquifers in fractured media and explain the mechanisms of water (both surface and underground) distribution and flow. Remote sensing approaches, statistical analysis tools, and groundwater flow models were used to analyze the fracture pattern of the rock medium and hence to create a hydrogeological database necessary for a GIS application. The comparison of different thematic maps of several hydraulic parameters shows a high correlation between potential groundwater flow paths and the hydrographic network. This finding is indicative of the recharge-drainage type of relationship between underground and surface water systems.