Mediterranean floods are causing major damage, and recent studies have shown that, despite the increase in intense rainfall, there has been no increase in river floods. This study reveals that the seasonality of floods changed in the Mediterranean Basin during 1959–2021. There was also an increased frequency of floods linked to short episodes of intense rain, associated with a decrease in soil moisture. These changes need to be taken into consideration to adapt flood warning systems.

Studying the impact of global change on water resources is essential for the West African Sahel (WAS), which is known for its fragility. In the Sahelian part of the Nakanbé watershed, located in Burkina Faso, the impact study indicated that environmental change and its interactions were the main drivers of runoff change over the period 1965-1994. Our results show that appropriate environmental management strategies could contribute to sustainable land and water resources management in the WAS.

Le district de Djibouti est situé dans le bassin versant de l’Oued Ambouli qui par sa nappe aquifère procure la source principale d’alimentation en eau potable de la ville de Djibouti, mais est aussi à l’origine de crues rares et brèves avec de lourds bilans humains et économiques Le développement du district se traduit par une expansion urbaine et un développement des activités qui accentuent le risque inondation.

Aghien lagoon is a source of fresh water outskirts of Abidjan city in the south of Côte d’Ivoire. For a better understanding of its functioning, we proposed to estimate its main tributaries (Bété and Djibi) soil loss during 2016 and 2017 as part of our research activities in the lagoon watershed in order to evaluate its vulnerability face to soil loss. The methodological approach is based on USLE (Universal Soil Loss Equation) incorporated into GIS (Geographic Information Systems).

This dataset provides a set of hydrometric indices for about 1500 stations across Africa with daily discharge data. These indices represent mean flow characteristics and extremes (low flows and floods), allowing us to study the long-term evolution of hydrology in Africa and support the modeling efforts that aim at reducing the vulnerability of African countries to hydro-climatic variability.

In the present study the flood trends have been assessed for a large sample of 171 basins located in southern France, which has a Mediterranean climate. Results show that, despite the increase in rainfall intensity previously observed in this area, there is no general increase in flood magnitude. Instead, a reduction in the annual number of floods is found, linked to a decrease in soil moisture caused by the increase in temperature observed in recent decades.

In order to define a dry period, a threshold for wet days is usually considered to account for measurement errors and evaporation. In the present study, we compare the threshold of 1 mm d⁻¹, the most commonly used threshold, to a time-varying threshold describing evapotranspiration to compare how the risk of extreme dry spells is estimated with both thresholds. Results indicate that considering a fixed threshold can underestimate extreme dry spells during the extended summer.