TITLE:
Study of the Spatio-Temporal Variability of Rainfall in the Nouhao Sub-Basin
AUTHORS:
Aminata Zeba, Wendkuni Ghislain Noba, Lucien Damiba, Abdoulaye Kabré, Ali Doumounia, Soumaila Ouédraogo, Frédéric Ouattara, François Zougmoré
KEYWORDS:
Climate Variability, Spatio-Temporal, Rainfall, Break, Trend, Nouhao Sub-Basin
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.17 No.8,
August
18,
2025
ABSTRACT: Wide variations characterize rainfall trends in the Sahelian zone. Indeed, this zone is considered to be one of the most affected by climatic fluctuations. This study aims to analyze the spatio-temporal variability of rainfall in the Nouhao sub-basin. To this end, data on annual rainfall from 1981 to 2022 were collected from rainfall stations located in the basin, namely Dialgaye, Tenkodogo, Sangha, and Ouargaye in the Centre-Est region of Burkina Faso. Rainfall indices were calculated to identify years with wet, dry or normal periods. Additionally, the Pettitt test was used to detect break years in the rainfall data. The Mann-Kendall test was used to assess any trends in the rainfall series. The results show that rainfall has been highly variable, with a general upward trend. In addition, the Pettitt test identified rainfall breaks in 1990 at Ouargaye and Sangha, in 2003 at Dialgaye and in 2004 at Tenkodogo. The rainfall surplus obtained from the break years ranges from 12% to 21%, with an average value of 16%. The highest surpluses were recorded in Sangha (16%) and Tenkodogo (21%). The spatial distribution of mean annual rainfall over the period 1981-2020 reveals significant variations, marked by a shift in isohyets from northwest to southeast.