|
giswr
> events
> 1st nhda symposium
> monday >
ned-h
National Elevation Dataset-
Hydrologic Derivatives (NED-H)
The National Elevation Dataset - Hydrologic Derivatives
(NED-H) is intended to develop a hydrologically correct
version of the NED and systematic derivation of standard
hydrologic derivatives. The recent completion of the NED
and the NHD combined with advances in GIS application of
terrain modeling have made possible the development of these
topographically derived hydrologic data layers at a scale
of 1:24,000. Some of the benefits of a nation-wide development
of hydrologic derivatives are:
- NED-H derived drainage basin boundaries can be used
to provide high-resolution boundaries for the new National
Watershed Boundaries Dataset (NWBD). The NWBD strives
to identify the "best-available" watershed boundaries
on a national level.
- NED-H will provide the capability of developing drainage
basin boundaries above any point within the U.S. All locations
downstream from any point in the U.S. can also be readily
determined using the NED-H derivative data layers.
- NED-H will serve to integrate the NED and the NHD, with
the NHD reach code providing the bridge between the rich
cartographic feature content of the NHD and the rich topographic
content of the NED. Enhancements to both datasets are
expected as quality control procedures used in the development
of the NED-H provide feedback to both NED and NHD. The
NHD will be further enhanced by consistency with the NED-H.
Elevation-derived streamline and basin parameters can
be transferred onto the NHD following conflation with
the NED-H. This will provide valuable attributes useful
in model parameterization.
For more information on the National Elevation Dataset
- Hydrologic Derivatives, see http://edcnts12.cr.usgs.gov/ned-h
.
|
