Enhancing the success of new dams implantation under semi-arid climate, based on a multicriteria analysis approach: Case of Marrakech region (Central Morocco)

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.