Mapping of areas with the potential to provide adequate groundwater supplies in arid regions: a case of the Isly basin (Horst Belt, northeastern Morocco)

In the Isly basin, an arid region in Morocco, access to water resources is a key factor in its socio-economic development. The purpose of the present study is to contribute to the search for areas suitable for the establishment of productive water wells by mapping areas that have the potential to provide a suitable water supply. The mapping process used a conceptual model of the factors that are controlling the distribution of groundwater in the region together with the use of remote sensing methods and a geographic information system (GIS) to cover the entire region (920 km2). Data on five parameters influencing groundwater storage (rainfall, lithology, rock fracture, slope, and drainage) were integrated into an empirical model and validated using well discharge data and the location of springs. Results show that the survey area is potentially rich in groundwater, with over 60% of the Isly basin having a “moderate” to a “very high” potential for groundwater storage. The empirical model makes up an important decision support tool since it allows suitable groundwater drilling targets to be identified.