Combined effects of pumped-storage operation and climate change on thermal structure and water quality
The assessment of ecological impacts of pumped-storage (PS) hydropower plants on the two connected water bodies is usually based on present climatic conditions. However, significant changes in climate must be expected during their long concession periods. We, therefore, investigate the combined effects of climate change and PS operations on water temperature and quality, as well as extent and duration of stratification and ice cover, using a site in Switzerland. For this purpose, a coupled two-dimensional hydrodynamic and water quality model for the two connected water bodies is run with 150 years long synthetic stochastic meteorological forcing for both current and future climate conditions under two PS and two reference scenarios. The results show relevant synergistic and antagonistic effects of PS operations and climate change. For example, hypolimnion temperatures in September are projected to increase by < 0.6 °C in a near-natural reference scenario and by ~ 2.5 °C in an extended PS scenario. Ice cover, which occurs every year under near-natural conditions in the current climate, would almost completely vanish with extended PS operation in the future climate. Conversely, the expected negative impacts of climate change on hypolimnetic dissolved oxygen concentrations are partially counteracted by extended PS operations. We, therefore, recommend considering future climate conditions for the environmental impact assessment in the planning of new or the recommissioning of existing PS hydropower plants.
We want to thank Dirk Schlabing for his insights on the weather generator. Moreover, we acknowledge P. Meier, who tackled Python library issues during the weather generator set up. We would also like to thank two anonymous reviewers and K. Rinke for valuable suggestions to improve this manuscript.
This study was funded by the Swiss Federal Railways (SBB AG).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Byrne MP, O'Gorman RA (2016) Understanding decreases in land relative humidity with global warming: conceptual model and GCM simulations. J Clim 29:9045–9061Google Scholar
- CH2011 (2011) Swiss climate change scenarios CH2011. C2SM, MeteoSwiss, ETH, NCCR Climate and OcCC, Zurich, Switzerland, p. 88Google Scholar
- Cole TM, Wells SA (2013) CE-QUAL-W2: A two-dimensional, laterally averaged, hydrodynamic and water quality model, version 3.71. User manual. Department of Civil and Environmental Engineering, Portland State UniversityGoogle Scholar
- EU (2009) Directive 2009/28/EC of the European Parliament and of the Council of 23 April 2009 on the promotion of the use of energy from renewable sources and amending and subsequently repealing Directives 2001/77/EC and 2003/30/EC.2009Google Scholar
- Fischer AM, Liniger MA, Appenzeller C (2015) Climate scenarios of seasonal means: extensions in time and space, CH2011 Extension Series No. 2Google Scholar
- Prats J, Salençon M-J, Gant M et al (2018) Simulation of the hydrodynamic behaviour of a Mediterranean reservoir under different climate change and management scenarios. J Limnol 77:62–81Google Scholar