Trends and variability of climate and river flow in context of run-of-river hydropower schemes: a case study of Sunkoshi river basin, Nepal

摘要

The increasing trend of glacier retreat and climate change/variability has direct impact on run-of-river hydropower schemes. This study analyses climate change risk in a Himalayan Sunkoshi river basin which consists of several existing/under-construction run-of-river hydropower schemes. Climate change impact has been examined by comparing observed and projected hydro-climatic trends. Projected monthly climatology (based on A1B emission scenario) of Meteorological Research Institute, Japan has been employed for the analysis. Observed annual minimum and lean season (January, February, March and April) discharges, which have larger significance for run-of-river schemes were analysed to identify any significant trend. The annual minimum and lean season monthly discharges were found with decreasing trend. Comparison of present and future precipitation pointed out that there will be 4.3% increase in monsoon (June, July, August and September) precipitation and 10.4% decrease in remaining months. Similarly, the study revealed that monthly temperature will be increased by 1.5 to 4.6℃.