Troubled waters

This chapter explores the unique hydrological dynamics of the Sahel, focusing on the counter-season surface water phenomenon, where delayed floods from major river systems like the Senegal, Niger, Chad and Nile bring water into the region from September to January, outside the rainy season. High-resolution satellite data reveal an increase in these seasonal water bodies, highlighting a “hydrological core” of persistently flooded areas that support local populations during dry months. However, this distinctive water availability is marked by high intrinsic variability and significant human impact from irrigation, dam construction and infrastructure development, which disrupt natural hydrological processes and degrade vital ecosystems. These factors contribute to the “troubled waters” of the Sahel, where balancing economic needs with environmental preservation is essential to managing the region's increasingly unpredictable hydrological landscape sustainably.