Impacts of Climate Change on Water Stress in West Africa: Case Study of the N’zi (Bandama) Watershed in Côte d'Ivoire

Abstract

The increased pressures on water resources linked to climate and societal changes are recognized as global challenges. The objective of this study is to analyze the impacts of climate change on the water stress of populations in the N'zi (Bandama) watershed in Ivory Coast. The data used (flows, populations, etc.) cover the period 1991-2020. An approach based on the comparison of water resources (standard normalization index, linear regression method, frequency analysis, flow rate index, etc.) and demands through the water needs satisfaction rate index, was applied at interannual and monthly scales. This approach has made it possible to identify the major trends in water stress in Dimbokro populations. It appears that on an interannual scale, the N'zi watershed is in a situation of water stress. The seasonal scale analysis shows that the city of Dimbokro experiences six months (December to May) of water stress. In the future horizons, the water stress of the city of Dimbokro could intensify.

Hydrological Impacts of Climate Change (Rainfall and Temperature) and Characterization of Future Drought in the Aga Foua Djilas Watershed

“…In the broad sense, we call "effective rain (Pe)", the rain-giving rise to a flow, superficial or underground, immediate or deferred. This term of the water balance conditions the availability of water, whether in terms of its rapid surface transfer (runoff) or its delayed flow through aquifers (Kouassi et al, 2017). The effective rainfall can be expressed by the following relationship (Equation 1): P e P-E """""""".""""""..…”

“…In this context of climate change, and to manage the water resources of the Aga-Foua -Djilas basin in a reasoned way, it is necessary to have as clear an idea as possible of how the catchment area will respond to changes. climate (Kouassi et al, 2017). The question raised by this study is therefore the following: What will be the hydrological impacts of climate change in the Aga-Foua -Djilas watershed?…”

Determination of the Thresholds of the Climatic Classification According to the Discharges in the Upper Senegal River Basin

“…The hydrological deficits indicated are therefore in the same magnitude as those obtained by several authors who have conducted hydrological studies, either in the same catchment or in other basins in Senegal, or in Africa. For example, the work of Kouassi et al [29] in the Bandama catchment indicates hydrological deficits of -16.32% for mean rainfall, -31.49% for effective rainfall, -59.94% for discharge potential and -15.17% for infiltration potential. Studies carried out in Africa by Sighomnou [30] and Goula et al [31] have highlighted the hydrological deficits following the decrease in rainfall.…”

Analysis of Land Use Change in the N'ZI Watershed of Côte d'Ivoire Using Landsat Satellite Images

“…Clear forests and forested savannahs experienced a decline of more than 14.95%, a decrease of 1.93% in dense forests and shrubby and/or grassy savannas of less than 15.15% were estimated using Landsat satellite images between 2000 and 1990 on the N'ZI catchment area using the Isodata classification method (A. M. Kouassi, 2010). Forests are composed of secondary degraded forests around the river N'ZI in particular (17% degraded forest, 10% clear forest and 3% gallery forest) (Noho et al., 2018).…”