A combined GIS, remote sensing, and geoelectrical method for groundwater prospect assessment and aquifer mapping in El-Hamiz Sub-watershed, Algiers, Algeria

As climate change intensifies, water supplies are declining and groundwater is increasingly being exploited worldwide to meet increased population needs, industrial growth, and agricultural development. Groundwater exploration relies mainly on hydrogeological studies, often supported by geophysical techniques (e.g., geoelectrical methods). Although these techniques can be cost-effective and time-efficient, they can be difficult to implement due to topographical effects or localized heterogeneities. Furthermore, when using ground-based geophysical measurements, it is impossible to survey large regions with dense coverage. We, therefore, require a means of targeting geophysical campaigns. The combination of Geographical Information System (GIS) and remote-sensing (RS) data can facilitate the identification of areas with high groundwater potential and suitable locations for geophysical surveys. In this study, we illustrate how GIS, RS, and geophysical surveys can be utilized for assessing potential groundwater resources. The study is based on two phases: a RS–GIS groundwater prospect modeling and a detailed geoelectrical survey (40 vertical electrical soundings, VES) for aquifer description in the El-Hamiz watershed (Algeria). The GIS–RS model was developed to highlight potential groundwater areas and locate the site of VES measurements. Furthermore, the geoelectrical data and hydrochemical analysis helped to determine the aquifer characteristics (depth to water table, saturated zone thickness, and aquifer resistivity). This study highlights the effectiveness of a combined use of RS–GIS modeling and geophysical data to improve the understanding of groundwater availability and its quality.