USDA Forest Service
20200205
050220
Western U.S. Stream Flow Metrics (Historical to 2080s, Absolute Change)
vector digital data
Detailed methods are described in: (1) Wenger, S.J., C.H. Luce, A.F. Hamlet, D.J. Isaak, and H.M Neville. 2010. Macroscale hydrologic modeling of ecologically relevant flow metrics. Water Resources Research. 46: W09513. doi:10.1029/2009WR008839. (2) Wenger, S.J., D.J. Isaak, and C.H. Luce, 2010. Comparison of hydrologic predictions from the Variable Infiltration Capacity (VIC) model and the MC1 model to observed gage data in the region around the Shoshone National Forest. Trout Unlimited/ US Forest Service Rocky Mountain Research Station, Boise, ID.
https://www.fs.fed.us/rm/boise/AWAE/projects/modeled_stream_flow_metrics.shtml
This feature class represents the absolute change in modeled streamflow metrics between the historical (1997-2006) and late 21st century (2070-2099) time periods in the western United States. In addition to standard NHD attributes, the streamflow dataset includes metrics on mean daily flow (year-round, summer, and August), flood levels associated with 1.5 year, 10-year, 25-year, and maximum modeled floods; number of winter flows over the 95th percentile; center of flow mass date; and base flow index. These files and additional information are available on the project website, https://www.fs.fed.us/rm/boise/AWAE/projects/modeled_stream_flow_metrics.shtml. Streams without flow metrics (null values) were removed from this dataset to improve display speed; to see all stream lines, use an NHD flowline dataset.
The flow regime is of fundamental importance in determining the physical and ecological characteristics of a river or stream, but actual flow measurements are only available for a small minority of stream segments, mostly on large rivers. Flows for all other streams must be extrapolated or modeled. Modeling is also necessary to estimate flow regimes under future climate conditions. Climate data such as this dataset is valuable for planning and monitoring purposes. Business use cases include: climate change and water rights assessments; analysis of water availability, runoff, groundwater, and impacts to aquatic organisms; resource management; post fire recovery; restoration activities, etc.
Climate change is projected to alter the flow regimes of streams and rivers, with consequences for physical processes, aquatic organisms, and water resource management. To study these hydrologic changes, we have developed a database of flow metrics for streams in the western U.S.(extent shown in Figure 1 of the User Guide, https://www.fs.fed.us/rm/boise/AWAE/projects/VIC_streamflowmetrics/downloads/WUS_VIC_Metrics_UserGuide.pdf) under historical conditions and climate change scenarios. These are based on daily simulations of the Variable Infiltration Capacity (VIC, http://cses.washington.edu/cig/data/wus.shtml) macroscale hydrologic model produced by the University of Washington Climate Impacts Group. The US Forest Service Rocky Mountain Research Station used these model outputs to calculate a set of summary flow metrics to describe key attributes of the flow regime for each stream segment in the 1:100,000 scale National Hydrography Dataset (NHDPlus version 2, http://www.horizon-systems.com/NHDPlus/NHDPlusV2_data.php) in the western United States. Datasets are available for the historical period (1977-2006), mid-century (2030-2059), and late-century (2070-2099) time periods. In the dataset attribute tables mid-century is represented as 2040s and late-century is represented as 2080s. Future datasets (2040s and 2080s) are based on the ensemble mean of ten global climate models associated with the A1B emissions scenario. Please see the User Guide for more information and important caveats on appropriate use. In particular, note that the 10+ year flood models are not appropriate for use in engineering and design applications.
20190528
publication date
None planned
-124.762581
-90.116669
49.039371
25.837681
None
Western US
Streams
Rivers
US Forest Service
Variable Infiltration Capacity
Flow Metrics
Climate Change
ISO 19115 Topic Categories
environment
None
The USDA Forest Service makes no warranty, expressed or implied, including the warranties of merchantability and fitness for a particular purpose, nor assumes any legal liability or responsibility for the accuracy, reliability, completeness or utility of these geospatial data, or for the improper or incorrect use of these geospatial data. These geospatial data and related maps or graphics are not legal documents and are not intended to be used as such. The data and maps may not be used to determine title, ownership, legal descriptions or boundaries, legal jurisdiction, or restrictions that may be in place on either public or private land. Natural hazards may or may not be depicted on the data and maps, and users should exercise due caution. The data are dynamic and may change over time. The user is responsible to verify the limitations of the geospatial data and to use the data accordingly.
USFS Chief Information Office, Enterprise Data Warehouse
data@fs.fed.us
United States Forest Service
Version 6.2 (Build 9200) ; Esri ArcGIS 10.5.1.7333
Gridded input data were visually inspected for completeness and reasonable values for the location. The data were not extensively compared against observational data.
Data is complete as of publication.
Inaccuracies in the data can stem from several sources: 1) Input meteorological data - We used the VIC dataset from Wenger et al., (2010) https://www.fs.usda.gov/treesearch/pubs/36238. Predictions were worse for sites with strong groundwater influence, and some sites showed errors that may result from limitations in the forcing climate data. Higher resolution (1/16th degree) modeling provided small improvements over lower resolution (1/8th degree). Despite some limitations, the VIC model appears capable of representing several ecologically relevant hydrologic characteristics in streams. 2) Stream hydrography - The National Hydrography Dataset version 2 is the highest resolution national stream hydrography layer currently available. As technology improves this component will likely become more accurate and increase our ability to represent small scale features and processes. Flow metrics were calculated for National Hydrography Dataset (NHD) version 2 stream segments that had a COMID (unique identifier) in the value added attributes table (VAA). Since not all stream segments in the NHD flowline layer are in VAA, not all stream segments have flow metrics. Headwater catchments with no area in the NHD did not accumulate flow and therefore do not have flow metrics. Secondary divergences do not receive flow from upstream, therefore only secondary divergences with a local catchment area have flow metrics. Note also that the 10+ year flood models are not appropriate for use in engineering and design applications.
For a full description of the process, see the Methods section in the user guide: https://www.fs.fed.us/rm/boise/AWAE/projects/VIC_streamflowmetrics/downloads/WUS_VIC_Metrics_UserGuide.pdf
20190101
Renamed feature class. Original feature class name: FlowMet_Hist2080_Abs
20190528
041100
USFS Chief Information Office, Enterprise Data Warehouse
Vector
String
887465
8.98315284119521e-009
8.98315284119521e-009
Decimal Degrees
D North American 1983
GRS 1980
6378137.0
298.257222101
S_USA.Hydro_FlowMet_W_2080_Abs
Feature class: A collection of geographic features with the same geometry type (such as point, line, or polygon), the same attributes, and the same spatial reference.
Esri GIS Dictionary
OBJECTID
Internal feature number.
Esri
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
Esri
Coordinates defining the features.
COMID
NHD Plus Version 2 COMID, a permanent identifier for each stream segment.
USDA Forest Service
ID
FDATE
Date of last feature modification.
NHD Data Dictionary (https://nhd.usgs.gov/userGuide/Robohelpfiles/NHD_User_Guide/Feature_Catalog/Data_Dictionary/Data_Dictionary.htm)
Date in MM/DD/YYYY format
RESOLUTION
Source resolution. Currently NHD is available as separate resolutions. Plans are to develop a single-resolution database with the highest resolution data that can be generalized.
NHD Data Dictionary
High
1:24,000/12,000
NHD Data Dictionary
Medium
1:100,000
NHD Data Dictionary
Local
>1:12,000
NHD Data Dictionary
GNIS_ID
Unique identifier assigned by GNIS, 10-char value. GNIS_ID = "null" if no name associated with the feature.
NHD Data Dictionary
ID
GNIS_NAME
Proper name, specific term, or expression by which a particular geographic entity is known, length 65.
NHD Data Dictionary
Name
LENGTHKM
Length of a feature in kilometers
Geometry
The length of a feature in kilometers.
REACHCODE
Unique identifier. The first eight digits are the WBD_HUC8. The next six digits are randomly assigned, sequential numbers that are unique within a HUC8, length 14.
NHD Data Dictionary
Code
FLOWDIR
Direction of flow relative to coordinate order, length 4.
NHD Data Dictionary
Textual description
WBAREACOMI
Permanent identifier of the waterbody through which the flowline flows
NHD Data Dictionary
ID
FTYPE
Feature type
NHD Data Dictionary
Textual description
FCODE
Five-digit integer value; comprised of the feature type and combinations of characteristics and values.
NHD Data Dictionary
Code
SHAPE_LENG
Length of feature in internal units.
Esri
Positive real numbers that are automatically generated.
ENABLED
Internal field for data processing
USDA Forest Service
Text
GNIS_NBR
Internal field for data processing
USDA Forest Service
ID
MA_2080
Mean annual flow is calculated as the average daily flow for every day of the water year, averaged across all years in the time period.
USDA Forest Service
cubic feet per second
MS_2080
Mean summer flow is the average of daily flow between June 1 (or the beginning of the low-flow season, whichever comes second, where the beginning of the low-flow season is defined as the first day to have a flow below the annual average) and September 30.
USDA Forest Service
cubic feet per second
MAug_2080
Mean August flow is the average of daily August flows for the time period. VIC is known to have trouble simulating baseflow and some snowpack dynamics, leading to underestimates of August flow. Thus, using this metric is not recommended, except for using it only in basins without significant groundwater contributions or drifting snow.
USDA Forest Service
cubic feet per second
W95_2080
Winter 95 is the number of daily flows between December 1 and March 31 which exceed the 95th percentile of daily flows across the entire year.
USDA Forest Service
number of days
Q1_5_2080
The 1.5 year flood is calculated by first finding the annual maximum series of flows (i.e. the highest flow each year). The 33rd percentile of the annual maximum series defines the flow that occurs every 1.5 years, on average.
USDA Forest Service
cubic feet per second
Q10_2080
The 10 year flood is calculated by first finding the annual maximum series of flows (i.e. the highest flow each year). The 90th percentile of the annual maximum series defines the flow that occurs every 10 years, on average.
USDA Forest Service
cubic feet per second
Q25_2080
The 25 year flood is calculated by first finding the annual maximum series of flows (i.e. the highest flow each year). The 96th percentile of the annual maximum series defines the flow that occurs every 25 years, on average. Note that the 10+ year flood models are not appropriate for use in engineering and design applications.
USDA Forest Service
cubic feet per second
Max_2080
The Maximum maximum modeled flood is calculated by first finding the annual maximum series of flows (i.e. the highest flow for each year), then finding the highest flow from all years. Note that the 10+ year flood models are not appropriate for use in engineering and design applications.
USDA Forest Service
cubic feet per second
CFM_2080
Center of flow mass/center of timing. CFM is calculated using a weighted mean: CFM=(flow1*1+flow2*2+[...]+flow365*365)/(flow1+flow2+[...]+flow365) where flow is the flow volume on each day of the water year.
USDA Forest Service
day of the water year (which begins on October 1st)
BFI_2080
Baseflow Index: ratio of lowest 7-day flow of summer (May 1-Sept 31) to average annual flow
USDA Forest Service
ratio
Region
Major drainage areas of the United States
NHDPlusV2
Data regions
http://www.horizon-systems.com/nhdplus/NHDPlusV2_data.php
SHAPE.LEN
Length of feature in internal units.
Esri
Positive real numbers that are automatically generated.
USFS Chief Information Office, Enterprise Data Warehouse
data@fs.fed.us
The U.S. Forest Service makes no warranty, express or implied, nor assumes any liability or responsibility for the accuracy, reliability, completeness, or utility of these geospatial data or for the improper or incorrect use of those data. The data are dynamic and may change over time. The user is responsible for verifying the limitations of the geospatial data and for using the data accordingly.
20200205
USFS Chief Information Office, Enterprise Data Warehouse
data@fs.fed.us
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
local time