Evaluating climate Change's impact on hydroelectricity in the Zambezi river basin

Abstract

This study investigates the effects of climate change on energy security in Africa, specifically focusing on the Upper and Lower Zambezi Basin. Data from the Kariba River basin sub-catchments, annual reports, the Climate Data Store, and Teal Tool Earth's country-by-country climate data were analysed through quantitative and qualitative data analysis techniques. The Mann-Kendal Trend Analysis was used to analyse time series and test the significance of changes to the climate. The historical climate and hydrological data analysis showed evidence of a slight increase in average rainfall amounts in the Zambezi River Basin but with high rainfall variability in some areas. Despite droughts increasing in frequency, there is a general increase in hydrological annual average water flow in the Zambezi River at two of the three sample sites. The increased water flow through the region could be attributed to population growth-induced land clearance and the degradation of wetlands in Angola's highlands. Although there is an increase in hydrological water flow into Kariba, there are water shortages for hydroelectricity generation due to increased generation capacity, resulting in increased demand for more water than in previous years. The unsustainable water abstraction to meet growing energy demands contributes to low water levels in the lake. The study recommends energy diversification and new hydroelectricity where the potential exists in the basin to reduce over-reliance on Lake Kariba with care not to disrupt the basin's hydrology and other economic activities. The study results provide insight into the potential effects of climate change on energy security in Africa.