The spatial distribution of rainfall and land use has important consequences for the hydrological and hydrogeological behaviour of a watershed. This study aims to better understand the impact of this distribution on aquifer recharge in the Bandama watershed. The spatialization of rainfall from isohyets, shows that it varies between 1200 mm and 1700 mm. The basin displays five (5) classes of land use that are: (1) dense forests, (2) open forests and / or savannahs, (3) shrub savannas, (4) bare soils and localities, and (5) water. The water balance shows that the excess which gives the surface flow and seepage is 348 mm upstream (Korhogo), and only 119 (Yamoussoukro) downstream. The total amount of water flowing over the Bandama basin at Yamoussoukro is 164.86 mm; which corresponds to an annual volume of run-off water of 4.338109 m3. The infiltrated water slide is 73.18 mm; which equates to an annual quantity of infiltrated water of 1.874109 m3.

The water resources of the Volta watershed in Côte d'Ivoire are often destined for human consumption and the development of agro-pastoral or industrial activities. This study aims to characterize climate variability and its consequences and to analyze the dynamics of land-use on the water resources of this basin, from hydrological models and GIS. Since the rainfall decline, observed during the years 1963 to 1970, several periods of drought have been observed and have caused the disappearance of plant species, some water bodies and some areas of groundwater recharge. The determined rainfall during the period 1936 to 2002 is 1102.86mm with only a surplus of 87.30mm of which 5.68% is destined for surface runoff and 2.23% for groundwater recharge. The flow rate of rivers from 1990 to 1993 is 1.39m3.s-1 with a drying up coefficient of 6.95.10-2 j-1 and a mobilized water volume by aquifers of only 0.028km3. These parameters determine a low hydraulic potential of the basin. Dominated by tree savannah or shrubby savannah (81.17%) in 1990, the degradation of the vegetation cover of the basin has had adverse effects on water resources. However, until the year 2000, the regeneration of gallery forest and dense tree savannah (from 8.48% to 16.01%) will favor the reconstitution of some water bodies. Thus, for an effective rehabilitation of the environment, it will be necessary to reinforce the strategic plans for adaptation to climate variability.