Elevation Data Sources
LIDAR Elevation Data for NC | Digital Elevation Models (DEMs) | Other Elevation Data Sources
LIDAR Elevation Data for North Carolina
Following Hurricane Floyd's flooding damage, North Carolina embarked on a joint effort with FEMA to re-map the state's flood zones. A by-product of this work is detailed elevation data collected by airborne LIDAR sensors. (NOTE: Raw pre-processed LIDAR data can be obtained from the NC Div. of Emergency Management for research needs. Contact them or Data Services with your inquiry).
For more information about the Floodplain Mapping Program, and full documentation on the LIDAR data collection process, go to http://www.ncfloodmaps.com. A LIDAR workshop was hosted by NCSU on August 4, 2004, and it's website has presentations and links to LIDAR data activity in NC.
LIDAR derived elevation data is available from the following sources:
- NCFloodmaps.com - Use the Map Viewer to zoom in and select the 10,000' X 10,000' tile(s) covering your area of interest. Then use the Elevation download button to download zip files of x,y,z ASCII formated files (see graphic below). For the entire state except the Cape Fear basin, 20' DEMs and 50' hydro-correct DEMs are available, or soon will be available*. The Cape Fear basin only has 50' hydro-correct DEMs.
These files can be converted using "ASCII to GRID" or a similar GIS software tool to an elevation raster. The data coordinate system is NC Stateplane, NAD 83, feet, and elevation values are in feet.
* Western NC data is projected to be available by the end of 2005. In the meantime, see the NC 10m DEM discussion.
- NCSU Alumnus Tom Colson has compiled the above referenced LIDAR data into 20' resolution DEMs, tiled by NC county. The difference between these files and what NCDOT has available (see the next listing below) is that the elevation values in this collection have NOT been rounded to the nearest foot. Instead, the floating point elevation values have been retained, which can be especially significant for applications down east.
As of November 2007, this is an incomplete collection. The graphic below shows which counties are available. The files can be downloaded from ftp://geodata.lib.ncsu.edu/dem/nc_20f (off campus link). There is a zip file for each county, which contains an asc file, prj file, and xml metadata file. The asc file must be converted to a grid using the "ASCII to GRID" conversion tool using the "Floating Point" option. An effort is underway to make the zip files available from a public webspace.
- NC Dept. of Transportation, GIS Unit - Download 20' resolution DEMs by NC county. This is the same data as available from the NC Floodmaps.com discussed above, but elevation values have been rounded to the nearest foot.
Also available from their website are Hillside Shade grids, Slop grids, and Contour vector data. FAQ's and further documentation are also available.
- USGS Seamless Distribution System - NC LIDAR data is being incorporated into the USGS Seamless Distribution System for download.
Digital Elevation Models (DEMs)
DEM data is readily available for download from the web or via the NCSU Geodata server. See the DEM webpage for links and further information.
Other Elevation Data Sources
Shuttle Radar Topography Mission (SRTM) - Nearly global coverage, 30 and 90 meter resolution.
NOAA Coastal Services Center, LIDAR Data Retrieval Tool (LDART) - LIDAR derived coastal topographic change database
GTOPO30 - Global Digital Elevation Model with a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer).
Geodata.gov - A search of the Geospatial One-Stop will reveal many other elevation datasets outside the scope of NCSU's collection.
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