Hydroclimatic trend analysis and projection in Africa tropical urban regions: Cases of Lusaka, Zambia and Kigali, Rwanda

Abstract

The global climate has significantly changed primarily due to human-induced activities. The incidences of droughts and extreme floods followed by destruction have been appearing across the globe along with extensive effects on economic and public health sectors, including the human lives losses whereby, Africa is among the greatly affected regions. Several studies aver that weather-related extremes are likely to increase due to the rising impacts. This article aims to emerge the effects of a warning climate on temperature and precipitation patterns in African tropical regions for pre-emptive adaptation practices. It was conducted using nonparametric Mann-Kendall's test and Sen's slope estimator coupled with the downscaled global climate models (NEX-GDDP-CMIP6 GCMs). The study shows that the annual precipitation in Lusaka keeps decreasing though the rainfall season showed an increasing possibility. The projection under ssp245 showed a slight rainfall decrement but increased by the mid-century under ssp585. Besides, the rainfall in Kigali, presents an excess increment resulting in increased extreme events. The projection showed up to 40% annual rainfall increment by the end-century under ssp585. However, both the regions present a slight trend increment in maximum and minimum temperature. Henceforth, the results of this study may prove useful in climate change mitigation and adaptation practices on rainfed agriculture, hydroelectricity, water supply systems, and resilient hydraulic infrastructure provision in the region.