Groundwater potential assessment using remote sensing and GIS-based multi criteria analysis – the case of Montserrado County, Liberia

Abstract

Liberia is marked by poor and insufficient hydrogeological data due to limited studies coupled with years of civil instability. Although Montserrado County has abundant water resources, lack of adequate knowledge of the available water resources has led to unsustainable groundwater utilization as well as investment losses from drilling unsuccessful boreholes. This research therefore aims at blending remote sensing with GIS-based multicriteria analysis to delineate suitable groundwater potential zones. Remote sensing and conventional data were used to construct a groundwater potential zone (GWPZ) map by integrating lineament and drainage densities, geology, slope and elevation, soil, annual rainfall, land use land cover, and the normalized difference vegetation index (NDVI) maps of the study area. The Analytic Hierarchy Process (AHP) was used in assigning weights to each thematic map, according to its influence on groundwater accumulation, for their integration. The results reveal that slope, lineament density, drainage density, geology, and land use land cover are parameters with the most influence (about 68%) on groundwater recharge within the area. The result also shows that about 10 %, 25 %, 30 %, 25 %, and 10 % of Montserrado County has very high, high, moderate, low zone, and very low groundwater potential zones, respectively. The study, therefore, provides very useful information that may guide the development and management of the groundwater resources within the study area.