PRESS RELEASE

Delaware Geological Survey (DGS) released a new elevation contour dataset for the entire state of Delaware with a contour interval of 1-foot. Elevation contours are lines of equal elevation that depict the shape of the land on a map, which form the basis of topographic maps. These data are routinely used by planners, engineers, and geoscientists—as well as recreational users such as hikers, hunters, and cyclists. The new contour data were generated from the 2014 acquisition of statewide LiDAR (which stands for light detection and radar) that was obtained using Hurricane Sandy federal supplemental funds.

The DGS, in partnership with the Delaware Department of Transportation, Department of Natural Resources and Environmental Control, and the Office of State Planning leveraged state matching funds to obtain the LiDAR data, which was used to create a detailed, three-dimensional model of the elevation of the land’s surface for the entire state. Acquisition of the 2014 LiDAR met Quality Level 2 specifications with a sampling density of greater than 2 points per square meter and an open terrain vertical accuracy of 6.3 cm. Subsequent computer processing and quality control, performed in cooperation with the U.S. Geological Survey, led to the creation of 1-foot elevation contours, which replaced an older generation of statewide 2-foot contours. The new contour data were designed to spatially align with existing datasets of water bodies (e.g., lakes, ponds, streams) already in use in Delaware.

“This new generation of highly-refined contour data is important for a low-elevation state such as Delaware, where they can be used for predicting areas prone to flooding related to coastal storms and sea-level rise, as well as for mitigating the impacts from these hazards” said David Wunsch, the Delaware state geologist and director of the DGS.

The elevation contour data are available from the DGS website in GIS-ready format (https://www.dgs.udel.edu/datasets/elevation-contours-delaware) and as map services from Delaware’s FirstMap GIS information and data portal (https://firstmap.delaware.gov/). For additional information contact the DGS at delgeosurvey@udel.edu.