Indicators of Hydroclimatic Extreme Hazards to Flooding in the Ouémé Watershed in Bénin

Abstract : Benin, like most of West African countries, has been in recent years affected by several episodes of extreme rainfall events, with disastrous consequences both in ecosystems as in local societies. This study aims to analyze the indicators of extreme hydroclimatic hazards during flooding in the Ouémé watershed at Bonou’s outlet. We used daily discharges and daily rainfall from 30 rainfall stations which are interpolated over 1951 to 2015. The unsupervised classification thresholder by percentile and the surveyed classification of the frequency of rainy days on fixed rainfall ranges, and in additional the index of daily rainfall intensity are used. Results indicate two main breakpoint at 1968 and 1987. The 1951-1968 was marked by strong hazards unlike to 1969-1987. The 1988-2015 compare to 1951-1968 experienced the same events but lower in thresholds to the latter. Results showed a decreasing of rainy according to 1-5 mm; 5-10 mm; 10-20 mm and rainfall greater than 50 mm. The same method has been applied to the 5-10 mm in the central and northern. The 90th, 95th and 99th percentiles of rainfall after the breakpoint are generally lower than what it got in the previous period. High floods very high floods and extreme flows are ranging from 59 to 1123 m3/s; 81 to 1161 m3/s and 104-1330 m3/s. These results may be taken to decision support tools for the management of flooding at Ouémé watershed.
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https://hal.umontpellier.fr/hal-02105266
Contributeur : Mélanie Karli <>
Soumis le : samedi 20 avril 2019 - 15:16:39
Dernière modification le : mercredi 26 juin 2019 - 14:50:04

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  • HAL Id : hal-02105266, version 1

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Domiho Japhet Kodja, E Amoussou, José Ghislain Quenum, Mahé Gil, Jean-Emmanuel Paturel, et al.. Indicators of Hydroclimatic Extreme Hazards to Flooding in the Ouémé Watershed in Bénin. European Journal of Scientific Research, EuroJournals, 2018, 148 (3), pp.333-349. ⟨hal-02105266⟩

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