Rainfall variability associated with climate change
has enormous impacts on ecosystems, agriculture and people in West Africa but
few studies have been devoted to it. Monthly rainfall data from 1901 to 2013,
provided by the Global Precipitation Climatology Center dataset, were analyzed
using segmentation and empirical modal decomposition (EMD) methods to increase
our knowledge on past and recent spatio-temporal rainfall trends and their
impacts on the West African region. The results obtained showed that the peak
of rainfall during the short rainy season is observed in September in Côte d’Ivoire,
Ghana and Liberia. The temporal variability of this rainfall is marked by
several breakpoints whose durations range from 2 to 70 years. The periods of
change in the rainfall regime, characterized by the appearance of breakpoints,
vary from one country to another and are of unequal duration. The main
breakpoint appears after 1960. Periods of relative or normal increase or
decrease in precipitation are observed before and after 1960. The long-term
variability of this rainfall is characterized by a decrease in the amount of
rainfall over all West African countries. The results of this study can be used
as a tool to help raise awareness among populations for sustainable management
of water resources in response to climate change and its adverse effects.
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