NASA Langley resides in an area prone to tidal flooding. During events that were expected to lead to flooding, there were requests for maps showing the predicted flood level and what infrastructure may be impacted, as well as the magnitude of the impact. In order to assess the impact of storm surge tidal flooding, the Flood Impact Analysis Tool was developed to enhance the decision-making process with regard to storm preparation. The tool is based on ArcGIS software, and is Web-enabled to broadly disseminate the analysis capability. Using predictions from local weather sources such as the National Oceanic and Atmospheric Administration (NOAA), a range of scenarios can be displayed.

The analysis tool uses red highlights to indicate features (buildings, manholes, etc.) that are inundated during a +10 ft. MLLW flood condition. Buildings with a bold black border indicate facilities with basements for which first-floor level is not critical elevation, and the pop-up dialog box shows data that is available if the user clicks on a feature.

Upon entering a flood level, the user can visualize the area of flooding, view the flooded buildings, and if desired, the underground utilities impacted. The tool uses an elevation raster data set derived from topographic contours and planimetric data of buildings and underground utilities. In addition to extensive geodetic control for remotely sensed data such as LiDAR and high-resolution orthophotography, the data undergoes extensive quality control measures to validate the positional accuracy.

The user inputs the predicted flood level into a Water Level text box in either feet or meters. The application then begins loading the map corresponding to that level. Upon loading, the predicted water level will be visible and displayed as a blue image. The depth of inundation is depicted by the shade of blue, with darker blues representing greater depths. Inundated buildings are shown in red. Selecting the building will indicate the depth of water above the floor. A list of inundated buildings with depths of water for each is provided. Underground utilities such as electrical, communications, and steam can be selected.

This work was done by Robert Gage, Michael Golub, Shane Wolf, Chris Casad, William Ball, Raymond Gates, and John Smithson of Langley Research Center. NASA is seeking partners to further develop this technology through joint cooperative research and development. For more information about this technology and to explore opportunities, please contact This email address is being protected from spambots. You need JavaScript enabled to view it.. LAR-18340-1

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This article first appeared in the December, 2017 issue of Tech Briefs Magazine.

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