Attributes for NHDPlus Version 2.1 Catchments and Modified Routing of Upstream Watersheds for the Conterminous United States: Riparian National Land Cover Data for 2019 Versions for the Years 2001, 2004, 2006, 2008, 2011, 2013, 2016, and 2019

This tabular data set represents the percent of land cover classes in the riparian zone from the 2019 edition of the National Land Cover databases for the years 2001, 2004, 2006, 2008, 2011, 2013, 2016 and 2019 compiled for two spatial components of the NHDPlus version 2.1 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. These databases can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is the "National Land Cover Database (NLCD) 2019 Products (ver. 2.0, June 2021)" databases for the years 2001, 2004, 2006, 2008, 2011, 2013, 2016, and 2019 produced by the United States Geological Survey (DeWitt, 2021). The source data for riparian areas is the "U.S. Forest Service national riparian areas base map for the conterminous United States in 2019" (Abood and others, 2022). Final data values units are percent. The "NLCD 2019 Land Cover Conterminous United States" databases (NLCD 2019) are a 16-class (additional four classes in Alaska only) land cover classification scheme that has been applied consistently across all 50 United States and Puerto Rico at a spatial resolution of 30 meters. 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).