Select Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Network Routed Upstream Watersheds for the Conterminous United States (ver. 4.0, August 2023)

This metadata record describes a series of data sets of natural and anthropogenic landscape features linked to NHDPlus Version 2.1's (NHDPlusV2) approximately 2.7 million stream segments, their associated catchments, and their upstream watersheds within the conterminous United States. These data were developed by the Hydrologic Sytem's Team (HST) within the the United States Geological Survey's (USGS) National Water Quality Program (NAWQP). The data were linked to four spatial components of NHDPlusV2: individual reach catchments, riparian buffer zones around individual reaches, reach catchments accumulated downstream through the river network, and riparian buffer zones accumulated downstream through the river network. All data can be linked to NHDPlus using the COMID field in these tables and the ComID in the flowline shapefiles or FEATURID in the catchment files in the NHDPlus data suite. The datasets were derived using a topologically reconditioned version of the NHDPlusv2 routing network (Schwarz and Wieczorek, 2018). This database is used for the routing of upstream watersheds only. No cartographic changes were made to the original NHDPlusv2 in either the flowline or reach catchment line work. These data are listed under 11 themes which include: Chemical, characteristics such as nitrogen application or toxicity weighted use. Climate and Water Balance Model, characteristics such as model outputs of runoff, actual evapotranspiration or ground water storage. Climate, characteristics such as mean precipitation, temperature, relative humidity, or evapotranspiration. Geology, characteristics such as Hunt or Soller surficial geologies. Hydrologic, characteristics such as base flow or infiltration excess overland flow. Hydrologic Modifications, characteristics such as dam storage or tile drains. Landscape, land cover characteristics such as NLCD, CDL or NWALT. Population Infrastructure, characteristics such as population, housing, and road densities. Regions, characteristics such as EcoRegions, Physiography or Hydrologic Landscapes. Soils, characteristics such as STATSGO, soil salinity, and soil restrictive layer. Topographic Characteristics, characteristics such as basin area, slope and elevation These data allow researchers and managers to acquire landscape information for both catchments (i.e., the nearby landscape flowing directly into streams) and full upstream watersheds of specific stream reaches anywhere in the within the conterminous United States without having to perform specialized geospatial processing.