Attributes for NHDPlus Version 2.1 Catchments and Modified Routing of Upstream Watersheds for the Conterminous United States: Hydrologic Landscape Regions

This tabular data set represents the percent of Hydrologic Landscape Regions 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 "Hydrologic landscape regions of the United States" produced by the United States Geological Survey (Wolock, 2003). Units are percent. The "Hydrologic landscape regions of the United States" are a 20-class classification scheme of noncontiguous regions (HLRs) built on the basis of similarities in land-surface form, geologic texture, and climate characteristics (Wolock, 2003). 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).