Luise J Fischer (Switzerland) 1,2; Heini Wernli (Switzerland) 1; David N. Bresch (Switzerland) 2
1 - Institute for Atmospheric and Climate Science, ETH Zürich; 2 - Institute for Environmental Decisions, ETH Zürich
We present findings from a research-practice collaboration with stakeholders from Swiss hydropower production. Climatic conditions and their potential changes on the timescale of decades challenge the long-term resilience and profitability of hydropower production in Switzerland. We contribute to reducing the ‘usability gap’ between climate information and strategic decision-making by (a) assessing and taking into account how stakeholders judge knowledge to be legitimate and useful, and (b) by studying how hydropower generation and precipitation are influenced by atmospheric flow patterns over the North Atlantic and Europe, which can be categorized into weather regimes. For this purpose, we integrate two different perspectives.
For the first perspective, the concept of weather regimes is proposed as a filter between climate models and decision-making in the hydropower sector. Specifically, we investigate statistical relationships and spatial patterns between hydropower generation, precipitation and weather regimes in recent climate data from the ECMWF (European Centre for Medium-Range Weather Forecasts) and from MeteoSwiss (Federal Office of Meteorology and Climatology, Switzerland), and production data from a Swiss hydropower company. The second perspective is based on active engagement with the hydropower experts by means of meetings and immersive office days. Their knowledge is used to continuously assess the usability of the weather regime perspective to inform strategic, i.e. long-term decision-making in the sector. This transdisciplinary collaboration with two perspectives helps to co-produce new knowledge and fosters mutual learning. We obtain insights into the challenges faced by climate scientists who hope to provide societally relevant climate information, and also establish an understanding of usable climate information for swiss hydropower. Due to the weather regime categorization, we are able to assess how important knowledge about atmospheric flow patterns is for the hydropower sector on timescales of decades.
Detecting such regimes in projections of future climate is likely to be more robust than modeled precipitation, and therefore directly useful to hydropower producers. Our approach to integrate two perspectives helps achieving two goals simultaneously: It increases our understanding of the relevance of weather regimes for climate change impacts on the hydropower sector in Switzerland, and it improves the usability of climate model data for stakeholders. Thus, our project contributes to reducing the ‘usability gap’ and thereby increases the resilience of the hydropower sector. These insights can potentially be transferred to other sectors.