Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Routed Upstream Watersheds for the Conterminous United States:
Select Basin Characteristics
Dataset Identification:
Resource Abstract:
This tabular data set represents select basin characteristics compiled for two spatial components of the NHDPlus version 2
data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated
upstream through the river network. The select variables in this data set are parsed out into six different file themes as
follows: BASIN_CHAR_XXX_CONUS.txt (where XXX is CAT flowline catchment value, ACC is divergence routed accumulated value,
and TOT is total upstream routed accumulated value) contains information on stream slope (percent rise, also referred to as
the percent slope), basin slope (percent rise, also referred to as the percent slope), basin area, minimum basin elevation,
maximum basin elevation, mean basin elevation, and stream length. RDX_CONUS.txt contains information on road and stream crossings.
ROAD_DENS_XXX_CONUS.txt (where XXX is CAT flowline catchment value, ACC is divergence routed accumulated value, and TOT is
total upstream routed accumulated value) contains information on road density by road type. STREAM_DENSITY_CONUS.TXT stream
density, contains information on stream density (stream kilometers per square kilometer of basin). SINUOSITY_CONUS.txt contains
information on flowline reach sinuosity. FTYPE_PCT_CONUS.txt contains information on each flowline reach type as a percentage
to all flowline features per catchment. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier
COMID. The source data is the NHDPlus Version 2 data suite (U.S. Geological Survey (USGS) and the U.S. Environmental Protection
Agency (USEPA), 2012). Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream
through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two
methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate
the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek,
2016).
Citation
Title Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Routed Upstream Watersheds for the Conterminous United States:
Select Basin Characteristics
This data set was created by the U.S. Geological Survey's (USGS) National Water-Quality Assessment Project (NAWQA) which is
part of the USGS National Water Quality Program (NWQP). This effort was undertaken to estimate select basin characteristics
for NHDPlusV2 flowline catchments and upstream river networks to support statistical analysis, map display, and model parameterization.