Multi-Model Assessment of Climate Change Impacts on the Streamflow Conditions and Hydropower Potential in the Kasai River Basin,Central Africa

Les changements climatiques peuvent modifier les caractéristiques de l'écoulement fluvial et son potentiel de production d'hydroélectricité. Par conséquent, comprendre l'impact du changement climatique sur les conditions d'écoulement est essentiel pour promouvoir une gestion durable des ressources en eau et en énergie dans diverses régions. L'approche commune pour évaluer les impacts du changement climatique sur les systèmes de ressources en eau est basée sur l'utilisation des sorties des modèles de circulation générale (MCG) et sur leur introduction dans des modèles hydrologiques pour simuler l'écoulement naturel à l'avenir. Bien que cette méthode soit largement utilisée par la communauté des chercheurs pour l'évaluation des impacts, certaines incertitudes sont attribuées aux modèles hydrologiques et aux MCG. En particulier, dans les régions où les données sont rares, la représentation des bassins versants, même dans des conditions historiques, est très difficile.

Abstract

Changes in climate can alter the characteristics of streamflow and its potential to generate hydroelectricity. Therefore, understanding the impact of climate change on streamflow conditions is essential to promote sustainable water and energy resource management in various regions. The common approach to assess climate change impacts on water resources systems is based on using the outputs of General Circulation Models (GCMs) and forcing them into hydrological models to simulate natural streamflow in the future. While this method is widely used among the research community for impact assessment, there are some uncertainties attributed to both hydrological models and GCMs. In particular, in data scarce regions, representation of catchments even under historical conditions is highly challenging. Central Africa is an example of such regions with limited and poor hydroclimatic data quality. With a technically feasible potential of about 100,000 MW, the Congo River Basin has the largest hydropower potential in Africa and is one of the largest worldwide. However, only about 2.5% of this potential has been developed so far. This hydroelectric potential depends entirely on the potentials of the main tributaries, including the Kasai River. The Kasai River Basin (KARB) in Central Africa is the main sub-watershed of the Congo River Basin. It covers 897,500 km2 yet includes less than five active stations with limited data over time. Due to rich natural resources of minerals, water, and fertile lands, this area is one of the Special Economic Zones of the Democratic Republic of Congo. The great hydropower potential within the basin as a clean energy source can effectively accelerate the region's economic growth. However, the reliability of such a water-dependant resource has been understudied under changing climate. The low adaptive capacity, lack of integrated water resource management, and water-dependent economy make the KARB vulnerable to climate change.