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Water management has become one of the major interests in arid and semi-arid regions. Scientists have suggested different criteria and methodologies for the identification of suitable dam sites. According to our literature review, we have used two major methodologies for the selection of suitable dam site location: geographic information system and remote sensing (GIS/RS) and multicriteria analysis (MCA) integrated with GIS/RS. The most common criteria used for the selection of suitable dam sites were slope, rainfall, land use land cover, soil type, lithology, lineament density, and hydrographic typology. All the factors were superimposed to prepare the synthesis map of water-harvesting structures, each thematic layer’s weight was determined, and storage water potential indices were calculated using water accumulation conditions. According to the water-harvesting location map, where the spatial distribution of the excellent (5%), very good (9%), and good (17%) aptitude classes is established in the northeast and central parts of the westward zone, the average located in the center of the zone. Study and weak are located south of the map; the area of moderate (25%) to poor (44%) suitability is situated in the south and southwest zone. The MCA was validated using an existing dam across the study area, where the MCA provides for the dam located in the good and moderate zones. The approach adopted in this study can be applied for any other location globally to identify potential dam-construction sites. From the point of view of the literature of multicriteria analyses of water recovery, areas unsuitable for surface water harvesting and dam projects are suitable for groundwater recharge.

The geological and hydrogeological approach of the structure of the basin OuladBouSbaâ led to the definition of the geometry of the main aquifers. In general, the profiles show the complexity of the geological configuration. The filling of the depression of OuladBouSbaâ is from the Eo-Cretacian. At this level, the aquifer is recharged by direct water infiltration. The quaternary, Eocene, and Cenomanian-Turonian formations constitute the main aquifers. Horizontal as well as vertical heterogeneity lead to a higher diversification of aquifer characteristics. To define the origins and understand the groundwater flows in this complex zone, we used a multi-tracer approach with the analysis of major elements and the isotopes of δ2H and δ18O. The chemical composition is mainly governed by the interaction with the rock with low electrical conductivity except in areas around domestic landfills. Geochemical results analyzing groundwater in the Piper diagram show two distinct chemical facies: the sulfated calcium and magnesium, and the hyper-chloride calcium. The levels of δ18O range from −7.60 to −4.25 while those of δ2H vary between −53.07 and −27.03. Analyses of signature isotopes differentiate two groups. The first contains high levels of heavy isotopes (highest levels of δ2H and δ18O) having therefore been submitted to evaporation. The second with lower levels of δ2H and δ18O did not undergo evaporation. The first one belongs to the unconfined free aquifer while the second corresponds to the captive aquifer. [ABSTRACT FROM AUTHOR]