FOREST COVER CHANGE AND HYDROPOWER SUSTAINABILITY IN NEPAL: A CLIMATE VULNERABILITY ASSESSMENT

Nepals ambitious hydropower expansion and recent forest cover recovery are both threatened by accelerating climate change, yet the linkages between forest dynamics and hydropower sustainability remain poorly integrated. This study assesses how forest cover changeincluding deforestation, afforestation, and species composition shiftsinteracts with climate-induced hydrological alterations to affect hydropower viability across three Nepalese catchments: Kulekhani, Bhote Koshi, and Ratuwa. Using Landsat/Sentinel time-series (1990 2020), SWAT hydrological modeling under CMIP6 scenarios (SSP2-4.5, SSP5-8.5, 2030 2050), and an integrated Climate Vulnerability Index (CVI), we quantified forest change impacts on dry-season baseflow and sediment yield. Results show that while total forest cover increased in Kulekhani (+3.9%) and remained stable in Bhote Koshi, pine monoculture expansion (from 18% to 32% of forest area) exacerbated dry-season flow reduction (from 22% to 31%) and sediment increase (from 52% to 78% under high emissions). Broadleaf regeneration partially mitigated these impacts. Ratuwas ongoing deforestation (dense forest declined from 42% to 27%) could reduce dry-season baseflow by nearly 50% by 2050. The CVI ranked Bhote Koshi (0.73) and Kulekhani (0.68) as high vulnerability, with Ratuwa reaching high vulnerability (0.66) if deforestation continues. Weak policy coordination between forestry and energy sectors was evident across all catchments. We recommend prioritizing native broadleaf forest restoration in hydropower catchments, supported by payment for ecosystem services, to sustain dry-season flows, reduce sedimentation, and enhance climate resilience.