Savannah River, GA/SC (S120) Bathymetric Digital Elevation Model (30 meter resolution) Derived From Source Hydrographic Survey Soundings Collected by NOAA

Bathymetry for the Savannah River was derived from nine surveys containing 34,353 soundings. Two older, overlapping, less accurate surveys were omitted before tinning the data. The average separation between soundings was 59 meters. Seven of the nine surveys used dated from 1934. The remaining two surveys, located in the southeast, dated from 1971 and 1974. The total range of sounding data was 1.2 meters to -15.9 meters at mean low water. Mean high water values between 1.9 and 2.5 meters were assigned to the shoreline. Three 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 Savannah River has seven 7.5 minute DEMs and two one degree DEMs. 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.