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

Area of Science:

• Environmental Science
• Climate Science
• Energy Security Studies

Background:

• Climate change poses significant risks to energy security in Africa.
• The Zambezi River Basin, a critical water source, experiences complex hydrological shifts.
• Over-reliance on hydroelectricity, particularly from Lake Kariba, heightens vulnerability.

Purpose of the Study:

• To investigate the effects of climate change on energy security in the Upper and Lower Zambezi Basin.
• To analyze climate and hydrological data to understand trends and variability.
• To assess the impact of water flow changes on hydroelectricity generation at Lake Kariba.

Main Methods:

• Quantitative and qualitative data analysis of climate and hydrological records.
• Utilized data from Kariba River basin, annual reports, Climate Data Store, and Earth's country-by-country climate data.
• Employed Mann-Kendal Trend Analysis for time series analysis and climate change significance testing.

Main Results:

• Observed a slight increase in average rainfall in the Zambezi River Basin, coupled with high variability.
• Despite increased drought frequency, average annual water flow in the Zambezi River generally increased.
• Lake Kariba faces water shortages for hydroelectricity due to increased demand from higher generation capacity and unsustainable abstraction.

Conclusions:

• Climate change, alongside land use changes, affects water availability for energy production.
• Unsustainable water abstraction for energy exacerbates low water levels in Lake Kariba.
• Energy diversification and careful development of new hydroelectric potential are recommended to enhance energy security in the basin.