Impacts of Climate Change on Hydropower Generation in the Shire River Basin of Malawi

Abstract

This study examines the influence of climatic variability on river flow regimes and its implications for future hydropower generation in the Shire River Basin. The Mann-Kendall test and Sen’s slope estimator were employed to detect and quantify trends in historical climatic time series. Future hydrological responses were simulated using the Hydrologic Engineering Center - Hydrologic Modeling System (HEC-HMS), integrating high-resolution climate projections from the Climate Model Intercomparison Project Phase 6 (CMIP6) under the Shared Socioeconomic Pathways (SSPs), SSP2-4.5 and SSP5-8.5. Flow Duration Curves were used to assess the future impacts of the river flow regimes on hydropower generation. Future river flow regimes are projected to increase significantly across all scenarios, with the most pronounced rise observed under SSP5-8.5 during both the 2030–2064 and 2065–2100 periods. Elevated flows indicate an increased likelihood of flooding events within the basin, which may pose risks to hydropower infrastructure but also enhance generation potential. Conversely, low-flow conditions highlight the sector’s vulnerability to climate change, as reduced discharge could limit power production. The results of this study are expected to guide adaptive hydropower management and support sustainable energy planning in the country.