Modeling the Potential Impacts of Climate Change on a Small Watershed in Labrador, Canada

Abstract

Hydroelectric power producers are strongly dependent on the climate to deliver the fuel necessary to generate electricity. This fuel source is watershed runoff, which is manifested as the balance between components of the climate system, primarily precipitation and evapotranspiration. Climate change threatens to alter global hydrological regimes and impacts need to be assessed to determine production vulnerabilities and opportunities. In this paper, dynamically downscaled regional climate models from the North American Regional Climate Change Assessment Program (NARCCAP) are combined with statistical bias correction techniques to generate 30-year time series of temperature and precipitation for a base period (1980s) and a future period (2050s). These time series are transformed into streamflow using the WATFLOOD hydrological model that has been calibrated for a sub-basin of the Churchill River. Results are consistent with IPCC results and show increasing mean annual streamflow of approximately 9% between the base and future periods with larger increases in winter runoff and little or no change during late summer and fall. Inter-model comparison and probabilistic methods are used to provide further insight into simulation results.

Producteurs d'nergie hydrolectrique dpendent fortement du climat pour fournir l'nergie ncessaire pour produire l'lectricit. Cette source d'nergie est de ruissellement des bassins versants qui se manifeste comme l'quilibre entre les composantes du systme climatique, surtout les prcipitations et l'vapotranspiration. Les changements climatiques menacent d'altrer rgimes mondiaux climatologiques et hydrologiques et les impacts doivent tre valus afin de dterminer les vulnrabilits et les possibilits de production. Dans ce papier, de manire dynamique chelle rduite des modles climatiques rgionaux de la North American Climate Change Programme rgional d'valuation (NARCCAP) sont combines avec des techniques statistiques de correction du biais de gnrer des sries de 30 ans de la temprature et des prcipitations pour une priode de base (1980) et une priode venir (2050). Ces sries chronologiques sont transformes en dbit en utilisant le modle WATFLOOD hydrologiques qui a t calibr pour un sous-bassin de la rivire Churchill. Les rsultats sont cohrents avec les rsultats du GIEC et de montrer l'augmentation signifie coulement annuel d'environ 9% entre la base et les priodes futures avec des augmentations plus importantes de ruissellement d'hiver et le changement peu ou pas de fin de l't et l'automne. Comparaison des modles et des mthodes probabilistes sont utilises pour fournir un aperu plus loin dans les rsultats de simulation.

Acknowledgements

This study was part of a broader study at Memorial University in collaboration with Nalcor Energy that is examining the effects of climate change on the Lower Churchill Hydroelectric Generation Project. This work would not be possible without the generous financial support of Nalcor. In particular, the collaborative efforts of Marion Organ have been tremendously valuable. We would like to recognize Dr. Nicholas Kouwen for his help with setting up and running WATFLOOD. We would also like to thank NSERC for providing financial support. We wish to thank the North American Regional Climate Change Assessment Program (NARCCAP) for providing access to the data used in this study. NARCCAP is funded by the National Science Foundation, the U.S. Department of Energy, the National Oceanic and Atmospheric Administration, and the U.S. Environmental Protection Agency Office of Research and Development. Finally, we thank the two anonymous reviewers for providing valuable feedback and suggestions.