Coupling modeling and remote sensing for the determination of high-flow drilling locations in the Lobo watershed at Nibehibé in Côte d'Ivoire

Access to drinking water remains at the center of major development projects in Cote d'Ivoire, particularly in the Lobo watershed, located in the Precambrian basement area which is made up of magmatic and metamorphic rocks. The exploitation of the basin's groundwater is marked by numerous failures in the boreholes drilled. Thus, this study aims to implement a land management tool to identify areas of high aquifer productivity in order to reduce the failure rate of drilling in the Lobo watershed. The methodology adopted was to map the recharges and fractures through the coupling of agro-hydrological modeling with SWAT, remote sensing and GIS. The results obtained show that the SWAT model was sensitive to 13 hydrological parameters and particularly to groundwater-related parameters. The statistical and graphical criteria of the SWAT model showed good performances (the Nash-Sutcliffe "NS" and determination "R 2 " coefficients > 0.6) for the calibration period (1982-1993) and (NS and R 2 ≥ 0.5) for the validation period (1979-1981). The monthly volumes of water recharging the groundwater tables range from 43 m 3 to 5770 m 3 . The superposition of the recharge map on the fracturing map, based solely on geophysical surveys (presence of fractures), shows the potential sites for the installation of high flow boreholes. These sites could be located at the level of the mega fractures in the zones where the volumes of water reserves remain higher or equal to 3363 m 3 /month.