Manish Praja

Kathmandu University

Assessment of Hydropower Potential and its Sensitivity to Climate Change in the West Seti River Basin, Western Nepal

Biography

Manish Praja is a final-year M. Sc. student in Environmental Science Specialization in Glaciology at the Department of Environmental Science, Kathmandu University, Nepal, working under the supervision of Professor Dr. Rijan Bhakta Kayastha. He holds a Bachelor's degree in Civil Engineering from Tribhuvan University and previously worked as a Site Engineer at the Langtang Khola Hydroelectric Project (20 MW, Run-of-River) for Multi-Energy Development Pvt. Ltd. (2022–2024), gaining hands-on experience in hydropower infrastructure in high-altitude Himalayan environments. His research focuses on glacio-hydrological modeling, climate change impact assessment, GIS-based hydropower site identification, and water resources management in data-scarce mountain regions. He has presented his research at World Glacier Day, Kathmandu University School of Management, and the SIAS Symposium on Transforming Local Water Security.

Abstract

Hydropower development in glacierized Himalayan basins faces unprecedented uncertainty from climate change, yet integrated basin-scale assessments that couple cryospheric dynamics with infrastructure planning remain scarce, particularly in data-scarce regions such as Western Nepal. This study presents an integrated assessment of run-of-river hydropower potential and climate sensitivity for the West Seti River Basin (WSRB), Western Nepal, using the Glacio-hydrological Degree-Day Model (GDM v2.0) coupled with GIS-based terrain analysis and bias-corrected CMIP6 climate projections (SSP2-4.5 and SSP5-8.5). The GDM was calibrated against 20 years of daily discharge data (2000-2019), achieving Nash-Sutcliffe Efficiency values of 0.72-0.73 and volume differences within ±5.10 %. GIS analysis identified 32 viable RoR sites with a combined technical potential of 1,265 MW based on Q40 design discharge (156.0 m³/s). Future projections reveal contrasting trajectories: under SSP2-4.5, discharge peaks around 2052 (401 m³/s) before declining to 364.61 m³/s by 2100, indicating 'Peak Water' dynamics (glacier loss: 62 %); under SSP5-8.5, discharge surges to 537.25 m³/s by 2100 (glacier loss: 75 %), with August peak flows nearly doubling from 927.4 m³/s (2000–2019) to 1,797.96 m³/s, threatening existing spillway capacities. Both scenarios project consistent dry-season baseflow declines, with SSP5-8.5 reducing from 34.07 % to 30.92 % of total discharge by 2081–2100, indicating growing vulnerability in winter hydropower generation. These findings demonstrate that while mid-century warming may temporarily enhance hydropower generation, long-term sustainability depends critically on the global emissions trajectory. The integrated GDM-GIS framework provides a replicable template for climate-informed hydropower planning in data-scarce mountain regions, with direct policy relevance for Nepal's water-energy nexus.