| Abstract | Hydropower is the main energy source in all regions of the world. It acts as a pillar for socio and economic development and assures electricity security. However, hydroelectric energy is vulnerable to climate change. Climate change impacts such as variations in mean annual precipitation, seasonal & annual variability in precipitation and temperature increase have a considerable direct impact on the hydropower supply. Rising of temperature and changing in precipitation could have an effect on the hydrological regime significantly through different factors like as variations in seasonal extremes, shift sin the volume of the glacier, and changes in melting of snow and glacier. There are differences on a regional basis as to whether the impact of climate change is likely to decrease or increase in the precipitation and stream flows. The water resources of the Great Himalayan region are facing climate change impact, which might have significant implications for the well-being of the people in the area. The water availability in the Satpara Basin is mainly due to snow melting and rainfall contribution. The current study presents the impact of climate change on stream flows, and hydropower energy from the basin. The main limitation of the study is the lack of availability of hydro-meteorological data, which is covered by using the global sourced data. The output of three CCAM RCM’s under two RCPs’ 4.5 & 8.5 was bias corrected using linear scaling approach. Subsequently, precipitation and temperature were projected for three periods2011-2040(2020s’), 2041-2070 (2050s’),and 2071-2099(2080s’). The results showed that temperature is expected to be increased in future periods but with different magnitude. Temperature projection for the future period is higher in RCP 8.5 scenario than RCP 4.5. The change in average annual temperature under RCP 4.5 ranges from 0.8°C to 3.7°C during the period of 2011-2099. However, under RCP 8.5, projection of average annual temperature varies from 1.1°C to 6.6°C for the period 2011-2099. Regarding precipitation, different RCMs’ presented different results of the change in precipitation ranging from negative change to positive change. However, two RCMs’ showed that precipitation is expected to increase, but one RCM projected to decrease in precipitation. However, winter is going to be more intense, and summer is expected to be dry by three RCMs’ .The uncertainty of average annual change in projected precipitation for the period of 2011-2099 under RCP 4.5 cover the range of -6.3% to 10.1%. However, under RCP 8.5, the change of annual average precipitation is -1.2% to 15.3% for 2011-2099. Afterwards, the projected temperature &precipitation used as an input to the hydrologic model HEC-HMS (version 4.1). The annual Stream flows generated through HEC-HMS is expected to increase because of increase in temperature, as the snow and glacier melt contribution is the main source of stream flows in the basin. The projected stream flows under RCP 4.5 varies between 14-31%, while under RCP 8.5, variation ranges from 15-96% in period 2011-2099. The higher increase in low flows, in terms of percentage is greater in winter, because of the increase of temperature and precipitation in winter season. Afterwards, HEC-ResSim was used for reservoir simulation to examine the climate change impact on hydro power. The hydropower generation in Satpara Basin mainly depends upon the demands of irrigation and domestic supplies, thus, hydropower is the by-product of water demands. The model was run on the current demands of irrigation and domestic releases with the baseline period of 1975-2005. There are four power plants located at different altitudes. The projected variations in the power plants for the future periods were different because the hydropower generation of power plant-1 directly depends upon the head variations in the dam, iv while the variations of power plants 2, 3 &4 depends upon the supply of water in respective seasons. As, power plants-3&4 are not functioning due to construction of left canal bank system. Therefore, HEC-ResSim model was run on two scenarios: i) with the existing condition i.e P-1&2 are functioning, ii) adding P-3&4 with the current demand. P-3&4 uses the same inflows passing through P-1&2, but after fulfilling the demand of right bank canal system. For RCP 4.5&8.5, the variation of hydropower production of power plant-1ranges from 2.89 to 20% and 5 to 24%, respectively, during the period of 2011-2099. Power production of P-2 is projected to increase up to 9.3% and 14% in 2011-2099, under RCP 4.5 and RCP 8.5, respectively. Furthermore, variations in power production of P-3&4 are same as the equal amount of inflows are passing through them. So, production of P-3&P-4 are expected to increase up to 14% and 23% in 2011-2099, under RCP 4.5 and RCP 8.5, respectively. In the end, reservoir performance was computed using different indicators, which showed that reservoir performance is 100% reliable and fully resilient with respect to the existing demands. As the inflows are increasing in future periods, therefore, dam is meeting the existing demand efficiently. This study may be helpful in the planning and distribution of water in the canal system considering the hydroelectric supply in future. |