This layer represents modeled stream temperatures derived from the
NorWeST point feature class (NorWest_TemperaturePoints). NorWeST summer
stream temperature scenarios were developed for all rivers and streams
in the western U.S. from the > 20,000 stream sites in the NorWeST
database where mean August stream temperatures were recorded. The
resulting dataset includes stream lines (NorWeST_PredictedStreams) and
associated mid-points NorWest_TemperaturePoints) representing 1
kilometer intervals along the stream network. Stream lines were derived
from the 1:100,000 scale NHDPlus dataset (USEPA and USGS 2010; McKay et
al. 2012). Shapefile extents correspond to NorWeST processing units,
which generally relate to 6 digit (3rd code) hydrologic unit codes
(HUCs) or in some instances closely correspond to state borders. The
line and point shapefiles contain identical modeled stream temperature
results. The two feature classes are meant to complement one another for
use in different applications. In addition, spatial and temporal
covariates used to generate the modeled temperatures are included in the
attribute tables at
https://www.fs.fed.us/rm/boise/AWAE/projects/NorWeST/ModeledStreamTemperatureScenarioMaps.shtml.
The NorWeST NHDPlusV1 processing units include: Salmon, Clearwater,
Spokoot, Missouri Headwaters, Snake-Bear, MidSnake, MidColumbia, Oregon
Coast, South-Central Oregon, Upper Columbia-Yakima, Washington Coast,
Upper Yellowstone-Bighorn, Upper Missouri-Marias, and Upper Green-North
Platte. The NorWeST NHDPlusV2 processing units include: Lahontan Basin,
Northern California-Coastal Klamath, Utah, Coastal California, Central
California, Colorado, New Mexico, Arizona, and Black Hills.
