Paper published in a book (Scientific congresses and symposiums)
Trends in extreme rainfall events in Benin (West Africa), 1960-2000
Hountondji, Yvon-Carmen; De Longueville, Florence; Ozer, Pierre
2011In Proceedings of the 1st International Conference on Energy, Environment and Climate Change
Peer reviewed
 

Files


Full Text
ICEC2011_Full_Hountondji-etal.pdf
Author preprint (274.71 kB)
Submitted on August 8th, 2011
Download
Annexes
ICEC2011_Hountondji-etal_Figs2-5.pdf
Publisher postprint (352.31 kB)
High resolution figures (2 to 5)
Download

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
Rainfall; precipitation indices; drought; Benin; West Africa
Abstract :
[en] Global dataset of derived indicators has been compiled to clarify whether the frequency and / or the severity of rainfall extremes changed during the 1960 – 2000 period in the Republic of Benin in West Africa. This period provides the best spatial coverage of homogenous daily series, which can be used for calculating the proportion of global land area exhibiting a significant change in extreme or severe rainfall. We selected 12 indicators of extreme climatic events that are based on daily totals of precipitation. The six first indicators are the annual total precipitation (RTOT); the annual total of wet days (with daily rainfall >= 1mm, Rd); the simple day intensity index (SDII) calculated as the average rainfall from wet days; the annual maximum rainfall recorded during 1, 5, and 30 days (Rx1d, Rx5d, and Rx30d). The other six indices are based on the 95th and 99th percentiles calculated from the daily rainfall data over the 1961-1990 period, that is the 30-year period required by the World Meteorological Organization (WMO) for the calculation of normals. The 95th percentile defines a very wet day. The 99th percentile corresponds to an extreme rainfall event. Based on these percentiles, three extreme precipitation indices were chosen. Very wet day and extreme rainfall frequency are based on the annual count of days with rainfall >= 95th and 99th percentiles of 1961-1990 (R95p and R99p). Very wet day and extreme rainfall intensity corresponds to the annual total precipitation recorded from days with rainfall >= 95th and 99th percentiles of 1961-1990 (R95pSUM and R99pSUM). Very wet day and extreme rainfall proportion is the percentage of the annual total precipitation recorded from days with rainfall >= 95th and 99th percentiles of 1961-1990 (R95pTOT and R99pTOT) and measures how much of the total rain comes from very wet or extreme events. Only time series which had complete records from 1960 to 2000 were used. A total of 21 stations time series were extracted from national climate archives and collated into the unique dataset described here. National maps showing trends during the 1960-2000 period were produced. Results show that only the annual total precipitation, the annual total of wet days and the annual maximum rainfall recorded during 30 days present a significant decreasing trend while the other nine rainfall indicators appear to remain stable. These results are important findings for Benin since scarce works realized in neighbouring regions of West Africa describe a situation more prone to increases in extreme rainfall (in Nigeria [1]) or the opposite (in Guinea Conakry [2] and in Niger [3]) in a similar context of a clear reduction in the yearly precipitation amount. We call for further research on this topic in West Africa since water management is a major tool for sustainable development and poverty alleviation. [1] M. New, B. Hewitson, D.B. Stephenson, et al., “Evidence of trends in daily climate extremes over southern and West Africa,” J. Geophys. Res., vol. 111, 2006, D14102, doi:10.1029/2005JD006289. [2] E. Aguilar, A. Aziz Barry, M. Brunet, et al., “Changes in temperature and precipitation extremes in western central Africa, Guinea Conakry, and Zimbabwe, 1955–2006,” J. Geophys. Res., vol. 114, 2009, D02115, doi: 10.1029/2008JD011010. [3] P. Ozer, Y.C. Hountondji, O. Laminou Manzo, “Evolution des caractéristiques pluviométriques dans l’est du Niger de 1940 à 2007,” GEO-ECO-TROP, Vol. 33, pp. 11-30, 2009.
Disciplines :
Environmental sciences & ecology
Earth sciences & physical geography
Author, co-author :
Hountondji, Yvon-Carmen ;  Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Département des sciences et gestion de l'environnement
De Longueville, Florence ;  Facultés Universitaires Notre-Dame de la Paix - Namur - FUNDP > Département de géographie
Ozer, Pierre  ;  Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Département des sciences et gestion de l'environnement
Language :
English
Title :
Trends in extreme rainfall events in Benin (West Africa), 1960-2000
Publication date :
26 August 2011
Event name :
1st International Conference on Energy, Environment and Climate Change
Event organizer :
Ho Chi Minh University of Industry
Event place :
Ho Chi Minh City, Vietnam
Event date :
August, 26-27, 2011
Audience :
International
Main work title :
Proceedings of the 1st International Conference on Energy, Environment and Climate Change
Peer reviewed :
Peer reviewed
Available on ORBi :
since 26 July 2011

Statistics


Number of views
918 (41 by ULiège)
Number of downloads
1111 (41 by ULiège)

Bibliography


Similar publications



Contact ORBi