DOI: 10.5194/hess-19-4707-2015
Scopus记录号: 2-s2.0-84949035493
论文题名: Trends in floods in West Africa: Analysis based on 11 catchments in the region
作者: Nka B ; N ; , Oudin L ; , Karambiri H ; , Paturel J ; E ; , Ribstein P
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2015
卷: 19, 期: 11 起始页码: 4707
结束页码: 4719
语种: 英语
Scopus关键词: Catchments
; Climate change
; Land use
; Rain
; Runoff
; Time series
; Time series analysis
; Vegetation
; Climate patterns
; Contingency table
; Flood magnitudes
; Long term analysis
; Mann-Kendall trends
; Non-stationarities
; Normalized difference vegetation index
; Peak over threshold
; Floods
; catchment
; climate change
; climate effect
; flood frequency
; rainfall
; time series
; trend analysis
; vegetation index
; Sahel [Sub-Saharan Africa]
; Sudan
英文摘要: After the drought of the 1970s in West Africa, the variability in rainfall and land use changes mostly affected flow, and recently flooding has been said to be an increasingly common occurrence throughout the whole of West Africa. These changes have raised many questions about the impact of climate change on the flood regimes in West African countries. This paper investigates whether floods are becoming more frequent or more severe and to what extent climate patterns have been responsible for these changes. We analyzed the trends in the floods occurring in 11 catchments within West Africa's main climate zones. The methodology includes two methods for sampling flood events, namely the AM (annual maximum) method and the POT (peak over threshold), and two perspectives of analysis are presented: long-term analysis based on two long flood time series and a regional perspective involving 11 catchments with shorter series. The Mann-Kendall trend test and the Pettitt break test were used to detect nonstationarities in the time series. The trends detected in flood time series were compared to the rainfall index trends and vegetation indices using contingency tables in order to identify the main driver of change in flood magnitude and flood frequency. The relation between the flood index and the physiographic index was evaluated through a success criterion and the Cramer criterion calculated from the contingency tables. The results show the existence of trends in flood magnitude and flood frequency time series, with two main patterns. Sahelian floods show increasing flood trends and one Sudanian. catchment presents decreasing flood trends. For the overall catchments studied, trends in the maximum 5-day consecutive rainfall index (R5d) show good coherence with trends in flood, while the trends in normalized difference vegetation indices (NDVIs) do not show a significant agreement with flood trends, meaning that this index has possibly no impact on the behavior of floods in the region. © 2015 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78376
Appears in Collections: 气候变化事实与影响
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作者单位: EPHE, CNRS, Universite Paris, 4 Place Jussieu, Paris, France; International Institute for Water and Environmental Engineering, Ouagadougou, Burkina Faso; Institut de Recherche Pour le Developpement, UMR, HydroSciences Montpellier, Abidjan, Cote d'Ivoire
Recommended Citation:
Nka B,N,, Oudin L,et al. Trends in floods in West Africa: Analysis based on 11 catchments in the region[J]. Hydrology and Earth System Sciences,2015-01-01,19(11)