Study of the Spatio-Temporal Variability of Climate Extremes in the Nouhao Sub-Basin in Burkina Faso Over the Period 1981-2020

Abstract

Extreme weather events are attracting growing scientific interest due to their impact on natural and socio-economic systems. However, few studies have focused on extreme weather events in the regions of Burkina Faso, a Sahelian country in West Africa. The objective of this study is to analyze the spatio-temporal variability and trends of climate extremes (precipitation and temperatures) in the Nouhao sub-basin. To this end, the analysis is based on observational and ERA5 reanalysis data for rainfall and temperature parameters for the period 1981-2020. These data were used to calculate climate extreme indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI) using Rclimdex. Trends were assessed using the Mann-Kendall test and Sen's slope estimator, while spatial structures were analyzed by geostatistical interpolation (kriging). The study showed strong decadal variability in extreme precipitation indices, with no monotonic trend over the period 1981-2020. However, the study highlights strong variability in extreme temperature indices, with a general trend towards a decrease in cold extremes and an increase in hot extremes, reflecting a gradual warming of the temperature regime. These results constitute an important climate signal for water resource management and the development of climate change adaptation strategies in the Nouhao sub-basin.