National Geophysical Data Center (NGDC), NOAA Satellite and Information Service

Alternate Views: Get Data, FAQ, ISO Rubric, DOI Rubric, CSW, HTML, Components, XML

Southern Louisiana 1/3 arc-second NAVD 88 DEM

browse graphicPerspective view of DEM
Modeling and mapping of coastal processes (e.g. tsunamis, hurricane storm-surge, and sea-level rise) requires digital representations of Earth's solid surface, referred to as digital elevation models (DEMs). Some modeling utilizes structured, square-cell DEMs, while others utilize unstructured grids that have no regular cell size or pattern. Usually, these different DEM types are developed independently, even though they are built from the same source bathymetric and topographic datasets. The National Geophysical Data Center (NGDC), an office of the National Oceanic and Atmospheric Administration (NOAA), has developed two bathymetric-topographic square-celled DEMs and one bathymetric-topographic unstructured DEM of southern Louisiana. The DEMs were developed for the Hurricane Forecast Improvement Project (HFIP), with the purpose of developing a new methodology for unstructured grid production from structured square-celled grids. The 1/3 arc-second DEM referenced to North American Vertical Datum of 1988 (NAVD 88) was carefully developed and evaluated. A NAVD 88 to mean high water (MHW) 1/3 arc-second conversion grid derived from VDatum project areas was created to model the relationship between NAVD 88 and MHW in the southern Louisiana region. NGDC combined the NAVD 88 DEM and the conversion grid to develop a 1/3 arc-second MHW DEM. The NAVD 88 DEM was generated from diverse digital datasets in the region. The DEMs were developed to be used for storm surge inundation and sea level rise modeling. The source bathymetric and topographic datasets used in the development of the NAVD 88 DEM were utilized along with the NAVD 88 DEM and derivative grids to develop the NAVD 88 unstructured DEM.

Cite this dataset when used as a source.

Search and Download
Distribution Formats
  • netCDF (Version: 3.6.2)
    • File Compression: ZIP
Distributor DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Point of Contact DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
dem.info@noaa.gov
General Documentation
Associated Resources
  • NOAA HFIP Gridding Project
  • Digital Elevation Models of Southern Louisiana: Procedures, Data Sources, and Analysis
Originator
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Publisher
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Date(s)
  • publication: 2012-01-28
Edition: First
Data Presentation Form: mapDigital
Dataset Progress Status Complete
Data Update Frequency: As needed
Purpose: Developed for the Hurricane Forecast Improvement Project (HFIP)
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.
Time Period: 1888-01-01  to  Present
Spatial Reference System: urn:ogc:def:crs:EPSG::4326 urn:ogc:def:datum:EPSG::5103
Spatial Bounding Box Coordinates:
N: 29.7
S: 28.6
E: -89.8
W: -91.6
Spatial Coverage Map:
Themes
  • Earth Science > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography
  • Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry
  • Earth Science > Oceans > Bathymetry/Seafloor Topography > Water Depth
  • Earth Science > Land Surface > Topography > Terrain Elevation
  • Earth Science > Land Surface > Topography > Topographical Relief
  • Earth Science > Oceans > Coastal Processes > Coastal Elevation
  • DEM > Digital Elevation Model
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
  • WDC/MGG, BOULDER > World Data Center for Marine Geology and Geophysics, Boulder
  • H: 1 meter - < 30 meters
  • V: < 1 meter
  • Coastal Relief
  • Gridded elevations
  • Integrated bathymetry and topography
  • DATA ANALYSIS AND VISUALIZATION > GEOGRAPHIC INFORMATION SYSTEMS > WEB-BASED GEOGRAPHIC INFORMATION SYSTEMS
  • DATA MANAGEMENT/DATA HANDLING > DATA SEARCH AND RETRIEVAL
  • DATA ANALYSIS AND VISUALIZATION > VISUALIZATION/IMAGE PROCESSING
  • DATA ANALYSIS AND VISUALIZATION > GEOGRAPHIC INFORMATION SYSTEMS > WEB-BASED GEOGRAPHIC INFORMATION SYSTEMS
  • DATA MANAGEMENT/DATA HANDLING > DATA SEARCH AND RETRIEVAL
  • DATA ANALYSIS AND VISUALIZATION > VISUALIZATION/IMAGE PROCESSING
Places
  • Continent > North America > United States of America > Louisiana
  • Ocean > Atlantic Ocean > Gulf of Mexico
  • Vertical Location > Land Surface
  • Vertical Location > Sea Floor
  • South Louisiana
Use Constraints No constraint information available
Fees Fee information not available.
Source Datasets
  • NOS Hydrographic Surveys
  • USACE Hydrographic Surveys
  • NOAA Coastal Services Center Coastal Bathymetric-Topographic Lidar
  • NOAA Coastal Services Center Levee Topographic Lidar
  • Composite Shoreline and associated data of Louisiana State Composite, LA_COMP
  • Louisiana State topographic lidar
Lineage Statement Lineage statement not available.
Processor
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Processing Steps
  • All datasets obtained by NGDC were converted to common horizontal and vertical datums of NAD 83 geographic and NAVD 88, respectively, using Proj4 and VDatum transformation tool. They were also converted to common file format, ESRI point shapefiles, for visualization and inspection.
  • Datasets were visually inspected with ArcGIS for identification and editing of data anomalies. Datasets were then compared with overlapping datasets to ensure data consistency.
  • Coastline datasets were merged and adjusted to fit satellite imagery.
  • xyz files of the bathymetric data were surfaced using GMT's 'surface' tool onto a 1 arc-second grid that interpolated to fill empty cells. Points extracted every 10 meters along the coastline were also included to ensure that the bathymetric grid reached zero at the coast. The resulting netCDF grid was clipped to the coastline to remove values over land.
  • xyz files for each input dataset were gridded using MB-System's 'mbgrid' tool, which utilizes a high-tension spline interpolation method to fill grid cells with no input elevation values. Preferential weighting was given to more recent, higher-accuracy datasets. Gridding was performed with a 5% data buffer.
  • The NAVD 88 DEM was quantitatively evaluated by comparing with source datasets and with elevation values extracted from NGS geodetic monuments. It was visually evaluated by converting to UTM-zone coordinates (units of meters horizontally and vertically) and then creating a slope grid to identify gridding artifacts in the DEM.

Metadata Last Modified: 2012-12-21

For questions about the information on this page, please email: kelly.carignan@noaa.gov