Just Cerfing Vol. 7, Issue 8, August 2016 Volume 5, Issue 4, April, 2014 | Page 20

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Coastal Digital Elevation Models

of the world’s ocean floor through estimation of seafloor topography (Smith
and Sandwell, 1997). Since then, a variety of global bathymetric-topographic
models have been built (e.g., Amante and Eakins, 2009; Becker et al., 2009;
GEBCO, 2010).
Initially, regional and local DEMs were derived from limited, dispersed
measurements and map contours hand-drawn by cartographers and geomorphologists, who would infer, for example, that canyons continue downslope.
Advances in technology, such as airborne light detection and ranging (LIDAR)
and ship-mounted multibeam swath sonar, now permit the development of
DEMs almost exclusively based on dense data, with minimal interpolation
between cells where data are absent. Maps, charts, and contours are now often
derived from the DEM (Maune et al., 2007).
Throughout this paper, we will explore some of the challenges that may be
encountered during the construction and assessment of coastal DEMs, and we
offer some steps that could be taken to improve their accuracy.
DEM Applications
DEMs have a wide variety of uses. They are required for computer modeling
of surface processes, such as riverine flooding, ocean circulation, and coastal inundation. They support ecosystems management and habitat research,
ocean-and land-use planning, forecast and warning s