Observed changes in flood hazard in Africa
Floods represent a major natural hazard in Africa, causing over 27 000 fatalities during the period 1950–2019. Despite its relevance, little is known about changes in flood hazard across this continent due to the lack of long-term high-quality streamflow records. Here we use a newly assembled discha...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/abb90b |
| _version_ | 1797747781057642496 |
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| author | Yves Tramblay Gabriele Villarini Wei Zhang |
| author_facet | Yves Tramblay Gabriele Villarini Wei Zhang |
| author_sort | Yves Tramblay |
| collection | DOAJ |
| description | Floods represent a major natural hazard in Africa, causing over 27 000 fatalities during the period 1950–2019. Despite its relevance, little is known about changes in flood hazard across this continent due to the lack of long-term high-quality streamflow records. Here we use a newly assembled discharge dataset of African rivers, and provide a long-term comprehensive view of flood hazard across this continent. We show that the annual maximum peak discharge does not exhibit a monotonic pattern, but overall decreasing trends prior to 1980 and increasing trends afterwards, especially in western and southern Africa. Our results indicate that these differing trends can be ascribed to changes in extreme precipitation around 1980. Moreover, these changes in intense precipitation pre/post 1980 are due to increased thunderstorm activity associated with enhanced convective available potential energy and zonal vertical shear driven by cooling temperature trends over western Africa. The changes in flood hazard in southern Africa can be tied to changes in Namibia low-level jet. Therefore, the observed increase in flooding since 1980 suggests that it would be beneficial to improve the monitoring, modeling and communication of flood hazard to reduce the socio-economic impacts of these events. |
| first_indexed | 2024-03-12T15:55:31Z |
| format | Article |
| id | doaj.art-36819f314d6545d58e02be6ab6c320c9 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:55:31Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-36819f314d6545d58e02be6ab6c320c92023-08-09T14:55:51ZengIOP PublishingEnvironmental Research Letters1748-93262020-01-0115101040b510.1088/1748-9326/abb90bObserved changes in flood hazard in AfricaYves Tramblay0https://orcid.org/0000-0003-0481-5330Gabriele Villarini1https://orcid.org/0000-0001-9566-2370Wei Zhang2https://orcid.org/0000-0001-8134-6908HydroSciences Montpellier (Univ. Montpellier, CNRS, IRD) , 300, avenue du Professeur Emile Jeanbrau, 34090, Montpellier, FranceIIHR—Hydroscience & Engineering, The University of Iowa , Iowa City, Iowa, United States of AmericaIIHR—Hydroscience & Engineering, The University of Iowa , Iowa City, Iowa, United States of AmericaFloods represent a major natural hazard in Africa, causing over 27 000 fatalities during the period 1950–2019. Despite its relevance, little is known about changes in flood hazard across this continent due to the lack of long-term high-quality streamflow records. Here we use a newly assembled discharge dataset of African rivers, and provide a long-term comprehensive view of flood hazard across this continent. We show that the annual maximum peak discharge does not exhibit a monotonic pattern, but overall decreasing trends prior to 1980 and increasing trends afterwards, especially in western and southern Africa. Our results indicate that these differing trends can be ascribed to changes in extreme precipitation around 1980. Moreover, these changes in intense precipitation pre/post 1980 are due to increased thunderstorm activity associated with enhanced convective available potential energy and zonal vertical shear driven by cooling temperature trends over western Africa. The changes in flood hazard in southern Africa can be tied to changes in Namibia low-level jet. Therefore, the observed increase in flooding since 1980 suggests that it would be beneficial to improve the monitoring, modeling and communication of flood hazard to reduce the socio-economic impacts of these events.https://doi.org/10.1088/1748-9326/abb90bFloodsAfricatrendsextreme precipitation |
| spellingShingle | Yves Tramblay Gabriele Villarini Wei Zhang Observed changes in flood hazard in Africa Environmental Research Letters Floods Africa trends extreme precipitation |
| title | Observed changes in flood hazard in Africa |
| title_full | Observed changes in flood hazard in Africa |
| title_fullStr | Observed changes in flood hazard in Africa |
| title_full_unstemmed | Observed changes in flood hazard in Africa |
| title_short | Observed changes in flood hazard in Africa |
| title_sort | observed changes in flood hazard in africa |
| topic | Floods Africa trends extreme precipitation |
| url | https://doi.org/10.1088/1748-9326/abb90b |
| work_keys_str_mv | AT yvestramblay observedchangesinfloodhazardinafrica AT gabrielevillarini observedchangesinfloodhazardinafrica AT weizhang observedchangesinfloodhazardinafrica |