Updated CONUS river network attributes and geometry based on the NHDPlusV2, E2NHDPlusV2, and NWMv2.1 networks (ver. 3.0, November 2024)

These attributes are based on the NHDPlusV2 network geometry and modifications retrieved from the National Water Model V2.1 (NWMv2.1) and "E2NHDPlusV2_us: Database of Ancillary Hydrologic Attributes and Modified Routing for NHDPlus Version 2.1 Flowlines" (E2NHDPlusV2) datasets. The attributes included are: comid, tocomid, ftype, fcode, gnis_name, gnis_id, fromnode, tonode, divergence, streamleve, streamorde, streamcalc, reachcode, frommeas, tomeas, lengthkm, arbolatesu, pathlength, areasqkm, totdasqkm, hwnodesqkm, hydroseq, dnhydroseq, levelpathi, terminalpa, dnlevelpat, terminalfl, terminalfl, wbareatype, wbareacomi, slope, slopelenkm, roughness, vpuin, vpuout, rpuid, vpuid. These attributes are available in four formats: csv, fst, parquet, and geopackage. "fst" is a high-performance format for use with the R programming language "fst" package. "parquet" is a high-performance format for use with multiple programming languages (including python) that support the Apache Arrow Parquet format. Geopackage is an open standard geodatabase format and includes both the attributes and geometry included in this data release.

The comid field of these data can be used to join to the National Hydrography Dataset Plus V2.1 (NHDPlusV2) flowline comid or catchment featureid attributes. The included attributes follow the same data model as the NHDPlusV2 but include numerous updates and improvements to network connectivity. All attributes that depend on network connectivity have been recalculated.

Version 3.0 includes updated flowline geometry in a geopackage geodatabase file with node geometry digitized in agreement with the network topology and all derived attributes compatible with non-dendritic network assumptions. Version 3.0 also now includes specific records of edits applied to the NHDPlusV2 from the NWMV2.1 and E2NHDPlusV2 in seperate geopackage geodatabases. See the entity and attributes section of this metadata record for more information.

As noted below, many of these are derived directly from the NHDPlusV2 database. Others are selectively overridden according to modifications found in the NWMv2.1 and E2NHDPlusV2, and some have been recalculated based on algorithms defined in the NHDPlusV2 user's manual and implemented in the hydroloom R package.

References:
NHDPlusV2: https://www.epa.gov/waterdata/get-nhdplus-national-hydrography-dataset-…
hydroloom: https://doi.org/10.5066/P9AQCUY0
E2NHDPlusV2: https://doi.org/10.5066/p986kzem
NWMv2.1: https://www.nohrsc.noaa.gov/pub/staff/keicher/NWM_live/NWM_parameters/

Included Attributes:
comid: integer derived from NHDPlusV2,
tocomid: integer dendritic network connectivity derived from tonode/fromnode topology of
NHDPlusV2, E2NHDPlusV2, and tocomid attributes of the NWMv2.1 routelink file,
ftype: character derived from NHDPlusV2,
fcode: integer derived from NHDPlusV2,
gnis_name: character derived from NHDPlusV2,
gnis_id: integer derived from NHDPlusV2,
fromnode: integer recalculated with hydroloom,
tonode: integer recalculated with hydroloom,
divergence: integer derived from E2NHDPlusV2,
streamleve: integer recalculated with hydroloom,
streamorde: integer recalculated with hydroloom,
streamcalc: integer recalculated with hydroloom,
reachcode: character derived from NHDPlusV2,
frommeas: numeric derived from NHDPlusV2,
tomeas: numeric derived from NHDPlusV2,
lengthkm: numeric derived from NHDPlusV2,
arbolate_sum: numeric recalculated with hydroloom,
pathlength: numeric recalculated with hydroloom,
areasqkm: numeric derived from NHDPlusV2,
totdasqkm: numeric recalculated with hydroloom,
hwnodesqkm: numeric derived from NHDPlusV2,
hydroseq: integer recalculated with hydroloom and validated according to non-dendritic node/divergence network,
dnhydroseq: integer recalculated with hydroloom,
levelpathi: integer recalculated with hydroloom,
dnlevelpat: integer recalculated with hydroloom,
terminalpa: integer recalculated with hydroloom,
terminalfl: integer (1 or 0) recalculated with hydroloom,
wbareatype: character derived from NHDPlusV2,
wbareacomi: integer derived from NHDPlusV2,
slope: numeric derived from NHDPlusV2,
slopelenkm: numeric derived from NHDPlusV2,
roughness: numeric derived from NHDPlusV2
vpuin: logical derived from NHDPlusV2,
vpuout: logical derived from NHDPlusV2,
rpuid: character derived from NHDPlusV2,
vpuid: character derived from NHDPlusV2