Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Mean Annual R-factor, 1971-2000

This data set represents the average annual R-factor, rainfall-runoff erosivity measure, 
compiled for every catchment of NHDPlus for the conterminous United States. The 
source data are from Christopher Daly of the Spatial Climate Analysis Service, Oregon 
State University, and George Taylor of the Oregon Climate Service, Oregon State 
University (2002), who developed spatially distributed estimates of R-factor for the 
period 1971-2000 for the conterminous United States.
		
The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial 
datasets that incorporates many of the best features of the National Hydrography 
Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes 
a stream network (based on the 1:100,00-scale NHD), improved networking, naming, 
and value-added attributes (VAAs). NHDPlus also includes elevation-derived 
catchments (drainage areas) produced using a drainage enforcement technique 
first widely used in New England, and thus referred to as "the New England Method." 
This technique involves "burning in" the 1:100,000-scale NHD and when available 
building "walls" using the National Watershed Boundary Dataset (WBD). The resulting 
modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives 
that agree with the NHD and WBD. Over the past two years, an interdisciplinary team 
from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection 
Agency (USEPA), and contractors, found that this method produces the best quality 
NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset 
is organized by 18 Production Units that cover the conterminous United States.
		
The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's  Major River 
Basins (MRBs, Crawford and others, 2006).  MRB1, covering the New England and 
Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2.  MRB2, 
covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus 
Production Units 3 and 6.  MRB3, covering the Great Lakes, Ohio, Upper Mississippi, 
and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9.  
MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower 
and 10-upper.  MRB5, covering the Lower Mississippi, Arkansas-White-Red, and 
Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12.  MRB6, 
covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus 
Production Units 13, 14, 15 and 16.  MRB7, covering the Pacific Northwest River 
basins, contains NHDPlus Production Unit 17.  MRB8, covering California River basins, 
contains NHDPlus Production Unit 18.

Tags: cali, california, catchment, cogb, conterminous-united-states, elevation, geoscientificinformation, glmr, great-lakes-ohio-upper-mississippi-and-souris-red-rainy, inlandwaters, lmtg, lower-mississippi-arkansas-white-red-and-texas-gulf, major-river-basin, missouri, mori, mrb, mrb1, mrb2, mrb3, mrb4, mrb5, mrb6, mrb7, mrb8, nawqa, nema, new-england-and-mid-atlantic, nhdplus, pacific-northwest, panw, r-factor, rio-grande-colorado-and-great-basin, sagt, south-atlantic-gulf-and-tennessee, sparrow, usgs-ae4b5219-1f5c-4728-80fd-0a7bc11d4a40
Organization: Department of the Interior