Cartography of potential recharge areas of the Bonoua aquifer (Southeastern Côte d’Ivoire)
This work aims at the determination of favourable areas for the recharge of the Bonoua aquifer, using a cartographic approach and a Geographic Information System (GIS). The determination of these potential recharge areas of the aquifer required the integration of spatial information related to different parameters regulating the recharge, which are represented by thematic maps. A new classification has been done with a weighting of these parameters according to their degree of involvement in the recharge process, using a multicriterion analysis such as the Analytical Hierarchy Process (AHP) of Saaty. In order to establish the map of potential recharge areas for the Bonoua aquifer, the weighting parameters were incorporated in the GIS. Analysis of the resulting map revealed five classes, included one class of better recharge covering 66% of the studied area. This dominant class is located at the central part of the aquifer, especially in the Terminal Continental, which is largely composed of coarse sands with relatively shallow slopes, where the land is used by industrial cultures. The areas of low recharge (34% of the studied area) are located at the western and eastern borders of the studied area on hydromorphic soils. This map showing the spatial distribution of the recharge areas could be considered as a decision-making tool, especially for management of the water resource and analysis of groundwater vulnerability. The preferential recharge areas need particular attention from authorities in order to ensure protection of the aquifer.