Progress on the NorWeST Stream Temperature Climate Scenarios
Anthropogenic climate change is warming rivers and streams across the Northwest U.S. and threatens many of the region’s valuable aquatic resources. Effective threat response will require prioritization of limited conservation resources and coordinated interagency efforts guided by accurate information about climate, and climate change, at scales relevant to the distributions of species across landscapes. Here, we describe progress on the NorWeST (i.e., NorthWest Stream Temperature) project to develop a comprehensive interagency stream temperature database and high-resolution climate scenarios for all streams across Washington, Oregon, Idaho, Montana, and Wyoming (~350,000 stream kilometers). The NorWeST database consists of stream temperature data contributed by >60 state, federal, tribal, and private resource agencies and may be the largest of its kind in the world (>45,000,000 hourly temperature recordings). These data are being used with spatial statistical stream network models to develop accurate (R2 = 90%; RMSE <1°C) scenarios at 1 kilometer resolution. The NorWeST stream temperature model is forced with air temperature data from RegCM runs for the NCEP historical reanalysis and the GENMOM model representing the A2 warming scenario at years 2050 and 2090 (http://regclim.coas.oregonstate.edu). At present, stream climate scenarios based on more than 16,000 summers of monitoring data have been developed for 180,000 stream kilometers across Idaho and western Montana. The temperature data and stream climate scenarios from this project are made available as ArcMap geospatial products for download through the NorWeST website as individual river basins are completed (http://www.fs.fed.us/rm/boise/AWAE/projects/NorWeST.shtml). A series of related projects are being developed that use NorWeST stream climate scenarios, including: 1) biological vulnerability assessments, 2) definition of species’ thermal niches, 3) improvement of bioclimatic models, 4) development of decision support tools, and 5) refinement of temperature and biological monitoring programs. Additional project details are contained in this Great Northern Landscape Conservation Cooperative newsletter (http://greatnorthernlcc.org/features/streamtemp-database).