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.

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. 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, fcode, nameID, lengthkm, reachcode, frommeas, tomeas, arbolate_sum, terminalpa ,hydroseq, levelpathi, pathlength, dnhydroseq, areasqkm, totdasqkm, terminalfl, dnlevelpat. 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.

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. 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, fcode, nameID, lengthkm, reachcode, frommeas, tomeas, arbolate_sum, terminalpa ,hydroseq, levelpathi, pathlength, dnhydroseq, areasqkm, totdasqkm, terminalfl, dnlevelpat. 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.

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. The attributes included are: comid, tocomid, fcode, nameID, lengthkm, reachcode, frommeas, tomeas, arbolate_sum, terminalpa ,hydroseq, levelpathi, pathlength, dnhydroseq, areasqkm, totdasqkm, terminalfl, dnlevelpat. 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 pythong) that support the Apache Arrow Parquet format.

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. The attributes included are: comid, tocomid, fcode, nameID, lengthkm, reachcode, frommeas, tomeas, arbolate_sum, terminalpa ,hydroseq, levelpathi, pathlength, dnhydroseq, areasqkm, totdasqkm, terminalfl, dnlevelpat. 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 pythong) that support the Apache Arrow Parquet format.

This dataset contains the initial 3D Hydrography Program (3DHP) flow network topology, which is based on the final High Resolution National Hydrography Dataset (NHD), and a set of mainstem river identifiers based on the Medium resolution NHDPlus Version 2 (NHDPlusV2). The 3DHP flow network topology and mainstem identifiers contained in this data release add two key pieces of information to the flow table of the National Hydrography Dataset: 1) at every junction, one and only one main upstream and downstream connection has been identified 2) every "in network" flowline has been assigned a mainstem identifier that places it into a hierarchy of rivers and drainage basins. For description of 1 and 2 and additional background, see supplemental information. Files included: - HU6_mainstem_outlets.geojson Outlet locations of six-digit hydrologic units along mainstem network. - nhd_3dhp_conus_mainstems.zip Zipped table in Comma Separated Values (csv) format containing NHD permanent identifiers and mainstem Uniform Resource Identifiers (URIs) for the Contiguous United States (CONUS). - nhd_3dhp_conus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for CONUS. - nhd_3dhp_conus_vpu_membership.zip Zipped csv table containing NHD permanent identifiers and which Vector Processing Unit (VPU) they belong in. - nhd_3dhp_oconus_mainstems.zip Zipped csv table containing NHD permanent identifiers and mainstem URIs for areas Outside of the Contiguous United States (OCONUS). - nhd_3dhp_oconus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for OCONUS. -3dhp_flownetwork.zip Zipped csv table containing from / to 3DHP identifiers (from flowline to flowline) and upmain / downmain attributes. - nhd_3dhp_nonnetwork_mainstems.zip Zipped csv table containing mainstem identifiers for features not included in the NHD flow table. - nhd_final_registry.zip Zipped csv table containing all expected flowlines from the final NHD -- excludes geometry. - nhd_reachcode_mainstem.zip Zipped csv table containing a mapping between mainstem identifiers and NHD reachcodes. - nhd_3dhp_region_connections.zip Zipped csv table containing connections between vector processing unit regions defined by four-digit hydrologic unit. - nhd_3dhp_mainstem_summary.zip Zipped csv table containing summary information about mainstems contained in nhd_3dhp_conus_mainstems.zip and nhd_3dhp_oconus_mainstems.zip.

This dataset contains the initial 3D Hydrography Program (3DHP) flow network topology, which is based on the final High Resolution National Hydrography Dataset (NHD), and a set of mainstem river identifiers based on the Medium resolution NHDPlus Version 2 (NHDPlusV2). The 3DHP flow network topology and mainstem identifiers contained in this data release add two key pieces of information to the flow table of the National Hydrography Dataset: 1) at every junction, one and only one main upstream and downstream connection has been identified 2) every "in network" flowline has been assigned a mainstem identifier that places it into a hierarchy of rivers and drainage basins. For description of 1 and 2 and additional background, see supplemental information. Files included: - HU6_mainstem_outlets.geojson Outlet locations of six-digit hydrologic units along mainstem network. - nhd_3dhp_conus_mainstems.zip Zipped table in Comma Separated Values (csv) format containing NHD permanent identifiers and mainstem Uniform Resource Identifiers (URIs) for the Contiguous United States (CONUS). - nhd_3dhp_conus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for CONUS. - nhd_3dhp_conus_vpu_membership.zip Zipped csv table containing NHD permanent identifiers and which Vector Processing Unit (VPU) they belong in. - nhd_3dhp_oconus_mainstems.zip Zipped csv table containing NHD permanent identifiers and mainstem URIs for areas Outside of the Contiguous United States (OCONUS). - nhd_3dhp_oconus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for OCONUS. -3dhp_flownetwork.zip Zipped csv table containing from / to 3DHP identifiers (from flowline to flowline) and upmain / downmain attributes. - nhd_3dhp_nonnetwork_mainstems.zip Zipped csv table containing mainstem identifiers for features not included in the NHD flow table. - nhd_final_registry.zip Zipped csv table containing all expected flowlines from the final NHD -- excludes geometry. - nhd_reachcode_mainstem.zip Zipped csv table containing a mapping between mainstem identifiers and NHD reachcodes. - nhd_3dhp_region_connections.zip Zipped csv table containing connections between vector processing unit regions defined by four-digit hydrologic unit. - nhd_3dhp_mainstem_summary.zip Zipped csv table containing summary information about mainstems contained in nhd_3dhp_conus_mainstems.zip and nhd_3dhp_oconus_mainstems.zip.

This tabular data set represents NLCD 2006 percent imperviousness 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. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is the "NLCD 2006 Percent Developed Imperviousness (2011 Edition, amended 2014) - National Geospatial Data Asset (NGDA) Land Use Land Cover" which was produced by the United States Geological Survey (Yang and others, 2011). Units are percent. 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, 2018).

This tabular data set represents NLCD 2006 percent imperviousness 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. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is the "NLCD 2006 Percent Developed Imperviousness (2011 Edition, amended 2014) - National Geospatial Data Asset (NGDA) Land Use Land Cover" which was produced by the United States Geological Survey (Yang and others, 2011). Units are percent. 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, 2018).

This tabular data set represents NLCD 2006 percent imperviousness 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. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is the "NLCD 2006 Percent Developed Imperviousness (2011 Edition, amended 2014) - National Geospatial Data Asset (NGDA) Land Use Land Cover" which was produced by the United States Geological Survey (Yang and others, 2011). Units are percent. 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, 2018).