TITLE:
Assessment of Intra-Seasonal Variability and Trends of Precipitations in a Climate Change Framework in West Africa
AUTHORS:
Daniel Bio Tore, Adechina Eric Alamou, Ezéchiel Obada, Eliezer Iboukoun Biao, Esdras B. Josué Zandagba
KEYWORDS:
Extreme Precipitation, Indices, Variability, Trend, Mann Kendall, West Africa
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.12 No.1,
January
28,
2022
ABSTRACT: Climate change has led human
beings to take an interest in the study of meteorological and climatic
phenomena. In fact, the main impact of climate change on different sectors of
society is caused by extreme events since the occurrence of extreme events
leads to more impact related to change in mean climate. Unfortunately, the West
African region is vulnerable to extreme rainfall impact because its economy is
based on rain-fed agriculture. This study examined the seasonal variability of
extreme rainfall in West Africa. Eight (8) climate indices were chosen from
among the 27 defined by the Expert Team on Climate Change Detection and Indices
(ETCCDI). The nonparametric Mann-Kendall test was used to assess the seasonal
trends. The indices of the same types (frequency or intensity) were compared to
assess the intra-seasonal variation of extreme precipitation. The results
indicate that, regardless of the season, the Gulf of Guinea receives more
rainfall than the Sahel. This phenomenon is due to the fact that the coastal
part of West Africa is under the influence of evaporation which is observed at
the Atlantic Ocean and during the monsoon, while the other part is dominated by
the desert. Mann-Kendall’s test revealed upward and downward trends during each
season. The increase in extreme rainfall trends in the number of consecutive
dry days suggests that droughts, due to global warming, could be observed and
could have severe consequences in terms of water availability, energy supply,
agricultural yields and ecosystems in West Africa. In addition, it can lead to
the loss of biodiversity and health issues. It is therefore essential for
policymakers or decisions makers to determine strategies and mitigation
measures against climate change and its impacts on populations.