Updated CONUS river network attributes based on the E2NHDPlusV2 and NWMv2.1 networks (ver. 2.0, February 2023)

The comid field of these data can be used to join to the NHDPlus version 2 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.

These attributes are based on the National Hydrography Dataset Plus V2.1 (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.

These attributes are available in three formats: csv, fst, and parquet. "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.

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 nhdplusTools R package.

Links:
NHDPlusV2: https://www.epa.gov/waterdata/get-nhdplus-national-hydrography-dataset-…
nhdplusTools: https://doi.org/10.5066/P97AS8JD
E2NHDPlusV2: https://doi.org/10.5066/p986kzem
NWMv2.1: https://www.nohrsc.noaa.gov/pub/staff/keicher/NWM_live/NWM_parameters/
Original Metadata: https://www.sciencebase.gov/catalog/file/get/63cb311ed34e06fef14f40a3?n…

The attributes included are:
comid: integer derived from NHDPlusV2,
tocomid: integer derived from tonode/fromnode topology of NHDPlusV2, E2NHDPlusV2, and tocomid attributes of the NWMv2.1 routelink file,
fcode: integer derived from NHDPlusV2,
gnis_id: integer GNIS_ID derived from NHDPlusV2,
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 nhdplusTools,
areasqkm: numeric derived from NHDPlusV2,
totdasqkm: numeric recalculated with nhdplusTools,
hydroseq: integer recalculated with nhdplusTools,
dnhydroseq:  integer recalculated with nhdplusTools,
levelpathi:  integer recalculated with nhdplusTools,
dnlevelpat: integer recalculated with nhdplusTools,
terminalpa: integer recalculated with nhdplusTools,
terminalfl: integer (1 or 0) recalculated with nhdplusTools,
pathlength: numeric recalculated with nhdplusTools.
streamleve: integer recalculated with nhdplusTools.
streamorde: integer recalculated with nhdplusTools.
vpuin: logical derived from NHDPlusV2,
vpuout: logical derived from NHDPlusV2,
wbareatype: character derived from NHDPlusV2,
slope: numeric derived from NHDPlusV2,
slopelenkm: numeric derived from NHDPlusV2,
ftype: character derived from NHDPlusV2,
gnis_name: character derived from NHDPlusV2,
gnis_id: integer derived from NHDPlusV2,
wbareacomi: integer derived from NHDPlusV2,
hwnodesqkm: numeric derived from NHDPlusV2,
rpuid: character derived from NHDPlusV2,
vpuid: character derived from NHDPlusV2,
roughness: numeric derived from NHDPlusV2