Estuarine Bathymetric Digital Elevation Models (30 meter resolution) Derived From Source Hydrographic Survey Soundings Collected by NOAA

These Bathymetric Digital Elevation Models (DEM) were generated from original point soundings collected during hydrographic surveys conducted by the National Ocean Service and its predecessors. Mean High Water shoreline as defined by NOAA nautical charts was used as a constraining boundary and assigned its local elevation relative to the local datum (typically Mean Low Water). In the event of multiple surveys in a region, the most recent survey soundings were retained. 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 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.
Cite this dataset when used as a source.
  • ID not available.
Other Access
Distribution Formats
  • NetCDF (Version: 1)
    • File Specification: NetCDF
Distributor DEM Information
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Time Period 1839-01-01 to 1989-01-01
Spatial Reference System
Spatial Bounding Box Coordinates
N: 50.00
S: 24.00
E: -65.00
W: -125.00
Spatial Coverage Map
Documentation links not available.
Publication Dates
  • publication: 1998-06-06
Dataset Progress Status Status not available
Data Update Frequency Not planned
Supplemental Information
The datum for these bathymetric DEMs is not the same as that used by the United States Geological Survey (USGS) for land based DEMs which results in a discontinuity if the two datasets are merged together. Moreover, the shoreline for the USGS DEMs is indeterminate and not the same as that used for the Bathymetric DEMs. Because of these differences, extreme care should be used in merging NOAA and USGS DEM data. 7.5-minute DEMs have rows and columns which vary in length and are staggered. The UTM bounding coordinates form a quadrilateral (no two sides are parallel to each other), rather than a rectangle. The user will need to pad out the uneven rows and columns with blanks or flagged data values, if a rectangle is required for the user's application. Some software vendors have incorporated this function into their software for input of standard formatted USGS DEMs. The data within the bathymetry file is floating point. When using the data within a GIS care must be taken to ensure that the data are being read as floating point and not integer data.
Purpose Bathymetric DEM's can be used as layers in Geographic Information Systems (GIS) for earth science analysis. DEM's can also serve as tools for volumetric analysis, for site location of structures, or for drainage basin delineation. The source soundings are collected by the NOS Office of Coast Survey (OCS).
Use Limitations
  • Not to be used for navigation. Although these data are of high quality and useful for planning and modeling purposes, they are not suitable for navigation. For navigation, please refer to the NOS nautical chart series.
  • Produced by the NOAA National Geophysical Data Center. Not subject to copyright protection within the United States.
  • National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Special Projects (SP)
    Publisher information not available.
Keywords not available
Use Constraints No constraint information available
Access Constraints
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
  • No Charge
Lineage information for: dataset
Source Datasets
  • NOS Hydrographic Survey Data
    • GEODAS vol 2 ver 3.3 (download)
      Digital database of NOS hydrographic surveys that date back to the late 19th century.
    • Description of Source: hydrographic surveys
    • Temporal extent used: 1839-01-01 to 1991-01-01
  • Medium Resolution Vector Shoreline
    • NOAA Shoreline Website (download)
      To provide clear information about vector shoreline data generated by federal agencies, as well as easy access to these data
    • Description of Source: composite shoreline
    • Temporal extent used: 1970-01-01 to 1990-01-01
  • Project control
    • Description of Source: Ground control points
Last Modified: 2017-04-14
For questions about the information on this page, please email: