| Broad River, SC (S110) Bathymetric Digital Elevation Model (30 meter resolution) Derived
From Source Hydrographic Survey Soundings Collected by NOAA |
| Bathymetry for the Broad River was derived from twenty-three surveys containing 98,479
soundings. No surveys were omitted. The average separation between soundings was 50
meters. Nineteen surveys dated from 1931 to 1934. The remaining four surveys, located
in the southern portion of the river, dated from 1971 to 1974. The total range of
sounding data was 1.5 meters to -21.3 meters at mean low water. Mean high water values
between 1.9 and 2.5 meters were assigned to the shoreline. Thirteen points were found
that were not consistent with the surrounding data. These were removed prior to tinning.
DEM grid values outside the shoreline (on land) were assigned null values (-32676).
The Broad River has eleven 7.5 minute DEMs and a single one degree DEM. The 1 degree
DEMs were generated from the higher resolution 7.5 minute DEMs which covered the estuary.
A Digital Elevation Model (DEM) contains a series of elevations ordered from south
to north with the order of the columns from west to east. The DEM is formatted as
one ASCII header record (A- record), followed by a series of profile records (B- records)
each of which include a short B-record header followed by a series of ASCII integer
elevations (typically in units of 1 centimeter) per each profile. The last physical
record of the DEM is an accuracy record (C-record). The 7.5-minute DEM (30- by 30-m
data spacing) is cast on the Universal Transverse Mercator (UTM) projection. It provides
coverage in 7.5- by 7.5-minute blocks. Each product provides the same coverage as
a standard USGS 7.5-minute quadrangle but the DEM contains over edge data. Coverage
is available for many estuaries of the contiguous United States but is not complete. |
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