USGS - science for a changing world

St. Petersburg Coastal and Marine Science Center

St. Petersburg Coastal and Marine Science Center > National Assessment of Storm-Induced Coastal Change Hazards > Hurricane Sandy

National Assessment of Storm-Induced Coastal Change Hazards

Hurricane Sandy

Pre-Storm and Post-Storm 3D Lidar Topography: Maryland

The USGS conducted an airborne lidar survey of the topography of Maryland and Delaware in November 2012, after Hurricane Sandy passed by to the East. In November 2009, the USGS conducted a similar survey after Ida (also known as "Nor'Ida") impacted the Northeast United States. Comparing these two surveys reveals the nature, magnitude, and spatial variability of hurricane-induced coastal changes, such as beach erosion, overwash deposition, and island breaching.

Location Map
Maryland-Delaware Index Map. Click on the yellow highlighted numbers to see maps of that location. The numbers correspond to the pre- and post-storm photograph comparisons. In the inset map, the green line is Hurricane Sandy's track and the red line indicates the shoreline where post-storm airborne lidar data were collected post Hurricane Sandy.

Below are pre-storm elevation maps, post-storm elevation maps, and elevation difference maps at each highlighted location. In the pre- and post-storm elevation maps, orange and red colors indicate higher elevations while yellow and green colors indicate lower elevations. In the elevation difference maps, red colors indicate erosion such as shoreline retreat, and blue-green colors indicate accretion, such as overwash deposits where waves and surge have moved sand landward. The location numbers correspond to the photo pair comparisons. The maps are oriented with the Atlantic Ocean on the bottom.

Location 6

Pre-Storm Elevation
pre-storm elevation for Assateague Island, Maryland

    Post-Storm Elevation
post-storm elevation for Assateague Island, Maryland

Elevation Difference
elevation difference for Assateague Island, Maryland
 
Location 6: Assateague Island, MD.
The pre-storm map shows a narrow, low-lying area that crosses the island from front to back. In the post-storm and difference maps, waves and surge deposited sand into the bay as an overwash fan and widened the island at this location. Beach erosion and overwash deposition occurred uniformly along this section of the barrier island.

Location 7

Pre-Storm Elevation
pre-storm elevation for Assateague Island, Maryland

    Post-Storm Elevation
post-storm elevation for Assateague Island, Maryland

Elevation Difference
elevation difference for Assateague Island, Maryland
 
Location 7: Assateague Island, MD.
The dunes along this stretch of island were constructed to protect the road and other infrastructure. They were relatively high, wide, and extended uniformly along the beach. After Hurricane Sandy the dunes were eroded in several places and overwash deposited sand on the landward side of the dune line and in the seaward-most parking lot.

Note: The results presented here are considered preliminary and have not been thoroughly reviewed or edited. They are based on preliminary data that may be updated as the survey accuracy improves in future processing steps such as application of the precise ephemeris for GPS satellites, offset checks using ground control surveys, checks for laser calibration and mounting errors, and full application of data quality control, assurance and editing procedures.


St. Petersburg Coastal and Marine Science Center > National Assessment of Storm-Induced Coastal Change Hazards > Hurricane Sandy

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo FirstGov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://coastal.er.usgs.gov/hurricanes/sandy/lidar/maryland.php
Page Contact Information: Feedback
Page Last Modified: December 05, 2016 11:24 AM (JSG)

Location 6 Location 7