Abstract:
This study investigates trends of climate extreme indices in the Komadugu-Yobe Basin (KYB) based on observed
data of the period 1971–2017 as well as regional climate model (RCM) simulations for the historical period
(1979–2005), the near future (2020–2050), and the far future (2060–2090). In order to correct change points in
the time historical series, the Adapted Caussinus Mestre Algorithm for homogenising Networks of Temperature
series homogeneity test is used. The magnitude of the linear trends is estimated using the Sen's slope estimator
and Mann-Kendall's test is performed to check the statistical significance of the trends. Future trends are assessed
using the ensemble mean of eight regional climate model data under two emission scenarios, provided by the
Coordinated Regional Climate Downscaling Experiment (CORDEX). Therefore, the projected rainfall and temperature have been corrected for biases by using empirical Quantile Mapping. In the observations, warm spell
duration, warm day-, and warm night frequencies exhibit statistically significant positive trends. Although there
is a positive trend in the annual total rainfall, the number of consecutive wet (dry) days decreases (increases).
The future climate also shows a continuing positive trend in the temperature extreme indices as well as more
frequent extreme rainfall events. Therefore, it is pertinent for decision-makers to develop suitable adaptation and
mitigating measures to combat climate change in the Basin.
