Some Aspects of Ice-Hydropower Interaction in a Changing Climate

Ice formation and related processes in rivers and lakes/reservoirs influence the operation of hydropower plants in cold regions. It is a matter of interest to the scientific community and hydropower operators alike how existing ice effects and problems will manifest themselves in a future changed climate. In this paper, we use different modeling results to investigate future freshwater ice conditions. The modeling approaches include using temperature derived winter indices, using one-dimensional (1D) hydrodynamic and ice cover model on three case study reservoirs, and using a 1D river hydrodynamic and ice cover model for a river reach. The analysis shows that changes in river and reservoir ice regimes due to climate change scenarios may have both positive and negative consequences for hydropower operation. Positive consequences emerge from reduction in ice season and reduced static ice loads. Negative consequences or challenges are attributed to unstable winters that may lead to increased frequency of freeze-thaw episodes with a shortened winter season. These aspects are discussed in more detail in the paper.