Debilitating floods in the Sahel are becoming frequent

Elagib, Nadir Ahmed Zayed Islam Sabry Al Saad Suhair A. Gayoum Mahmood Mohamad Ibrahim Basheer Mohammed Fink Andreas H.

[Display omitted] • Flash and riverine flood risks in the Sahel have become persistent and widespread recently. • Timing of occurrence of maximum rainfall is end of July to mid-August in Eastern Sahel, but to the end of August in Western Sahel. • Fatality, disease outbreaks and damage were exceptional in the aftermath of 2019 and 2020 floods in Sudan. • Changing natural climate patterns, soil characteristics, human interferences, and mal-governance drive catastrophic floods. • Overlooked debilitating floods hindered the opportunities for effective management plans. Despite the long-lasting and widespread drought in the Sahel, flood events did punctuate in the past. The concern about floods remains dwarf on the international research and policy agenda compared to droughts. In this paper, we elucidate that floods in the Sahel are now becoming more frequent, widespread, and more devastating. We analyzed gridded daily rainfall data over the period 1981–2020, used photographs and satellite images to depict flood areas and threats, compiled and studied flood-related statistics over the past two decades, and supported the results with peer-reviewed literature. Our analysis revealed that the timing of the maximum daily rainfall occurs from the last week of July to mid-August in the Eastern Sahel, but from the last week of July to the end of August in the Western Sahel. In 2019 and 2020, flash and riverine floods took their toll in Sudan and elsewhere in the region in terms of the number of affected people, direct deaths, destroyed and damaged houses and croplands, contaminated water resources, and disease outbreaks and deaths. Changes in rainfall intensity, human interventions in the physical environment, and poor urban planning play a major role in driving catastrophic floods. Emphasis should be put on understanding flood causes and impacts on vulnerable societies, controlling water-borne diseases, and recognizing the importance of compiling relevant and reliable flood information. Extreme rainfall in this dry region could be an asset for attenuating the regional water scarcity status if well harvested and managed. We hope this paper will induce the hydroclimate scholars to carry out more flood studies for the Sahel. It is only then encumbered meaningful opportunities for flood risk management can start to unveil. [ABSTRACT FROM AUTHOR] Copyright of Journal of Hydrology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)