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Digital elevation models (DEMs) of U.S. and other coasts that typically integrate
ocean bathymetry and land topography. The DEMs support NOAA's mission to understand
and predict changes in Earth's environment, and conserve and manage coastal and marine
resources to meet our Nation's economic, social, and environmental needs. NOAA's National
Centers for Environmental Information (NCEI) has built many of these models, and also
distributes DEMs on behalf of other NOAA offices, as well national and international
partners. Bathymetric, topographic, and shoreline data used in DEM development come
from a variety of sources, including NOAA's National Ocean Service (NOS) and NCEI,
the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), and the
Federal Emergency Management Agency (FEMA), as well as other federal, state, and local
government agencies, academic institutions, and private companies. The DEMs are referenced
to a variety of vertical tidal datums, typically mean high water (MHW) or North American
Vertical Datum of 1988 (NAVD 88), and usually a horizontal datum of North American
Datum of 1983 (NAD 83) or World Geodetic System 1984 (WGS84). DEM cell sizes range
from high-resolution models (1/9 to 1/3 arc-second; ~3 to 10 meters) that support
coastal inundation studies, to regional models (roughly 3 to 24 arc-seconds) that
extend farther offshore, to global models (1 arc-minute; ~2 km). |