HR: 09:45h
AN: CG21B-07    [Abstracts]
TI: Hydrologic modelling for climate change impacts analysis of shifts in future hydrologic regimes: implications for stream temperature and salmon habitat
AU: * Bennett, K E
EM: kbennett@uvic.ca
AF: Pacific Climate Impacts Consortium, University of Victoria Sedgewick Building PO BOX 1700 STN CSV, Victoria, BC V8W 2Y2, Canada
AU: Werner, A T
EM: wernera@uvic.ca
AF: Pacific Climate Impacts Consortium, University of Victoria Sedgewick Building PO BOX 1700 STN CSV, Victoria, BC V8W 2Y2, Canada
AU: Schnorbus, M
EM: mschnorb@uvic.ca
AF: River Forecast Centre, B.C. Ministry of Environment 4th Floor 395 Waterfront Crescent, Victoria, BC V8T 5K7, Canada
AU: Schnorbus, M
EM: mschnorb@uvic.ca
AF: Pacific Climate Impacts Consortium, University of Victoria Sedgewick Building PO BOX 1700 STN CSV, Victoria, BC V8W 2Y2, Canada
AU: Salathé, E P
EM: salathe@washington.edu
AF: Climate Impacts Group, Center for Science in the Earth System Joint Institute for the Study of the Atmosphere and Ocean (JISAO) University of Washington Box 355672, Seattle, WA 98195-5672, United States
AU: Nelitz, M
EM: mnelitz@essa.com
AF: ESSA Technologies, Suite 300 1765 West 8th Avenue, Vancouver, BC V6J 5C6, Canada
AB: The challenges faced by climate change impact analysts must be solved through interdisciplinary collaboration between research scientists, institutions and stakeholders. In particular, hydrologic modelers, climate scientists, biologists, ecologists, engineers and water resource managers must interact to pool expertise and provide tools to address the complex issues associated with future climate change. The current study examines the results of an application of the VIC macro-scale hydrologic model to predict future changes to soil moisture, snowpack, evapo-transpiration, and streamflow in the Fraser Basin of British Columbia - and then apply these results to stream temperature and fish habitat models to predict future impacts on freshwater ecosystems. The results of this work will be presented to fisheries managers to provide them with the information needed to develop adaptation strategies that will help mitigate the adverse effects of climate change. This presentation will focus on the hydrologic modelling results of a number of downscaled scenarios to examine the projected differences for the 2050s (2041 - 2070) as compared to the historical baseline (1961- 1990). By the 2050s, although the magnitude of change varies by GCM and emissions scenarios, overall precipitation and temperature is projected to increase, particularly in the winter, which leads to increased winter time runoff for many basins. However, this is combined with declines in snow water equivalent (SWE) for many sites, which coupled with lower early season soil moisture, leads to declines in summer runoff and baseflow. SWE increases in some basins under the cgcm3 A1B and echam5 A1B scenarios at high elevations. A similar result was found in this region with the Canadian Regional Climate Model (CRCM) 4, driven with run 4 of the CGCM3 under the A2 emissions scenario. Lack of water availability during the summer time periods appears to limit evaporation, causing declines in summer ET across most sites. Higher peak flows, a shift in the spring melt (earlier) and increased winter runoff are characteristics observed at many of the streamflow sites analysed. These results suggest that while an increase in winter rain events will cause higher peak flows, winter warming generally leads to lower snowpacks and soil moisture stores, leading to a decline in summer water availability in this region. Lessons learned from the applications of modelling data and results across different model frameworks and for different scales will be discussed.
DE: 1630 Impacts of global change (1225)
DE: 1807 Climate impacts
DE: 1847 Modeling
DE: 1860 Streamflow
DE: 1876 Water budgets
SC: Canadian Geophysical Union [CG]
MN: 2009 Joint Assembly