Contribution of remote sensing and GIS to the location of dam sites for groundwater recharge and flood control: case study in Cameroon (Mandara Mountains)

In the Sahelian zone of the Mandara Mountains in the far north of Cameroon, climate change is leading to a short rainy season with significant flooding and a long, intense dry season throughout the year. This has the effect of rarifying surface water through evaporation and depleting aquifers due to their low recharge. To solve this problem, with the combination of several factors obtained by processing Landsat 8 OLI and SRTM (Shuttle Radar Topography Mission) satellite images within a Geographic Information System (GIS), this work has mapped potential dam sites that promote groundwater recharge. These factors include river system, drainage and fracturing density, slopes, contours, and topography. Among the seven mapped dam sites, there are three dam sites with impoundment character located respectively West of Ouazzang, North of Mokolo, and West of Oupai, one dam site with impoundment and slow recharge character located South-West of Tchevi, and three dam sites with impoundment and recharge character located North-East of Hina, South of Tchevi and South of Bourrha. Apart from the site located north of Mokolo, where we note the presence of an exploitable dam, the sites located south of Bourrha and Tchevi, with respective lengths of 571.87 and 1940.36 m, have good characteristics such as low drainage and fracturing density, good slope, and the presence of geological faults necessary for aquifer recharge.