Modeling the Effects of Forecasted Climate Change on Streamflow in the Nooksack River Basin
Presentation Abstract
The Nooksack River drains an approximately 2000 km2 watershed in the North Cascades in Whatcom County, Washington and is a valuable freshwater resource for regional municipalities, industry, and agriculture, and provides critical habitat for endangered salmon species. With a maritime climate and a high relief basin with glacial ice (3400 hectares), the streamflow response in the Nooksack River is sensitive to increases in temperature, thus forecasting the basins response to future climate is of vital importance for water resources planning purposes, especially during low-flow months in the summer when precipitation is minimal. We apply the Distributed Hydrology Soil Vegetation Model (DHSVM; Wigmosta et al., 1992) with newly developed coupled dynamic glacier model (Clarke et al., 2015) to simulate hydrologic processes in the Nooksack River basin.
We calibrate and validate the DHSVM to observed glacial mass balance and glacial ice extent as well as to observed daily streamflow and SNOTEL data in the Nooksack basin using a gridded meteorological forcing data set (1950-2010; Livneh et al., 2013). We simulate forecasted climate change impacts, including glacial recession on streamflow, using gridded daily statically downscaled data from global climate models of the CMIP5 with RCP4.5 and RCP8.5 forcing scenarios developed using the multivariate adaptive constructed analogs method (Abatzoglou and Brown, 2011). Simulation results project an increase in winter streamflows due to more rainfall rather than snow, a decrease in spring snow-melt runoff with peaks that occurring earlier in the year, and lower summer flows. Glacier melt contribution to streamflow initially increases throughout the first half of the 21st century and decreases in the latter half after glacier ice volume decreases substantially.
Session Title
Linking Metrics to Climate Impact Pathways and Restoration Performance Monitoring across Puget Sound Floodplains and Estuaries
Conference Track
Climate Change and Ocean Acidification
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Location
2016SSEC
Type of Presentation
Poster
Genre/Form
presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Climatic changes--Forecasting; Streamflow--Washington (State)--Nooksack River; Glaciers--Computer simulation--Washington (State)--Nooksack River
Geographic Coverage
Nooksack River (Wash.); Salish Sea (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Modeling the Effects of Forecasted Climate Change on Streamflow in the Nooksack River Basin
2016SSEC
The Nooksack River drains an approximately 2000 km2 watershed in the North Cascades in Whatcom County, Washington and is a valuable freshwater resource for regional municipalities, industry, and agriculture, and provides critical habitat for endangered salmon species. With a maritime climate and a high relief basin with glacial ice (3400 hectares), the streamflow response in the Nooksack River is sensitive to increases in temperature, thus forecasting the basins response to future climate is of vital importance for water resources planning purposes, especially during low-flow months in the summer when precipitation is minimal. We apply the Distributed Hydrology Soil Vegetation Model (DHSVM; Wigmosta et al., 1992) with newly developed coupled dynamic glacier model (Clarke et al., 2015) to simulate hydrologic processes in the Nooksack River basin.
We calibrate and validate the DHSVM to observed glacial mass balance and glacial ice extent as well as to observed daily streamflow and SNOTEL data in the Nooksack basin using a gridded meteorological forcing data set (1950-2010; Livneh et al., 2013). We simulate forecasted climate change impacts, including glacial recession on streamflow, using gridded daily statically downscaled data from global climate models of the CMIP5 with RCP4.5 and RCP8.5 forcing scenarios developed using the multivariate adaptive constructed analogs method (Abatzoglou and Brown, 2011). Simulation results project an increase in winter streamflows due to more rainfall rather than snow, a decrease in spring snow-melt runoff with peaks that occurring earlier in the year, and lower summer flows. Glacier melt contribution to streamflow initially increases throughout the first half of the 21st century and decreases in the latter half after glacier ice volume decreases substantially.
