Climate change impact on hydropower generation and adaptation through reservoir operation in a Himalayan river, Tamor

Integrated assessment of climate change impact and water resource development scenario is crucial for planning and management. In the Himalayan river basin, it is of the utmost importance considering the vulnerability to climate change and the pace of water resource development. This study focused on Tamor River Basin (TRB) investigates the impacts of climate change on the energy generation from hydropower projects and analyzes the adaptation through reservoir operation. Analyzing the three run-of-the-river (RoR) hydropower projects and a storage project, this study projects future energy generation. The results showed that an RoR project is highly susceptible to the impacts, demonstrated by significant reduction during pre-monsoon of up to -53% and increment at annual scale of up to 28%. In the Tamor storage project (TSP), the particle-swarm optimization approach generated operational strategies according to altered streamflow conditions. This resulted in adaptation to the projected decrease in the March-June flow through flexible operation rules, yielding positive impact on energy generation (up to +7.3% on an annual scale). The new set of rules will adapt to the flow deficit and increase the dry season flow downstream by almost two times the historical baseline. This research highlights the significance of the reservoir project and its optimized operation in effectively managing water under the impact of changing climate.