Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: NLCD 2001 Imperviousness

This data set represents the mean percent impervious surface from the Imperviousness Layer of the 
National Land Cover Dataset 2001 (LaMotte and Wieczorek, 2010), compiled for every catchment of 
NHDPlus for the conterminous United States. The source data set represents imperviousness for the 
conterminous United States for 2001. The Imperviousness Layer of the National Land Cover Data Set 
for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land 
Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies 
(http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and 
Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. 
Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), 
the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA 
Natural Resources Conservation Service (NRCS).
		
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, environment, geoscientificinformation, glmr, great-lakes-ohio-upper-mississippi-and-souris-red-rainy, imperviousness, 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, rio-grande-colorado-and-great-basin, sagt, south-atlantic-gulf-and-tennessee, sparrow, usgs-e2d3b46b-e599-46f2-a79e-1415ac39825b
Organization: Department of the Interior