Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Mean Infiltration-Excess Overland Flow, 2002

This tabular data set represents the mean value for infiltration-excess overland flow as 
estimated by the watershed model TOPMODEL, compiled for every catchment of NHDPlus 
for the conterminous United States. Infiltration-excess overland flow, expressed as a 
percent of total overland flow, is simulated in TOPMODEL as precipitation that exceeds 
the infiltration capacity of the soil and enters the stream channel. The source data set is 
Infiltration-Excess Overland Flow Estimated by TOPMODEL for the Conterminous United 
States (Wolock, 2003).
		
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, infiltration-excess-overland-flow, 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-da491a39-a76a-40ad-887e-b6acac8a548f
Organization: Department of the Interior