Coastal Change Hazards: Hurricanes and Extreme Storms

Hurricane Ike

Post-Landfall Assessment of Potential Coastal-Change Impacts

Posted: 09/15/2008 5:30pm

Prior to hurricane landfall, the potential inundation of the beach system and associated coastal changes were assessed by comparing pre-storm dune/berm elevations to maximum surge elevations obtained from model simulations of hypothetical storm scenarios.

The post-landfall assessment of potential coastal-change impacts is done by comparing pre-storm dune/berm elevations to refined surge-elevation estimates obtained from model simulations based on the actual storm scenario. We are using NOAA's probabilistic surge predictions and have extracted the maximum at open coast locations from the 90th percentile surge forecast estimates.

The post-landfall assessment of the potential for inundation was assessed for the same five focus areas that were analyzed prior to landfall: South Padre Island, Matagorda Island, Galveston, Chenier Plain (southwest coast of LA), and Isles Dernieres. Extreme coastal change is expected to occur in areas where the updated surge levels indicate inundation (indicated by red on the figures).

Location of five focus areas and the track of Hurricane Ike. Green line represents storm track. Click on any of the five areas to see the updated potential inundation estimate for that area. Data also available in zipped KML format (218 KB), viewable with Google Earth.

South Padre Island, TX

Updated assessment of inundation potential (storm surge minus dune elevation) for South Padre Island, TX using modeled storm surge based on Hurricane Ike storm conditions and landfall location. In most areas, no inundation (blue colors) nor extreme coastal change is expected as the updated surge estimates rarely exceed the elevations of the primary dunes/berms. [larger version]

Matagorda Island, TX

Updated assessment of inundation potential (storm surge minus dune elevation) for Matagorda Island, TX using modeled storm surge based on Hurricane Ike storm conditions and landfall location. In most areas, moderate inundation (yellow colors) and high potential for coastal change are expected as the updated surge estimates exceed the elevations of the primary dunes/berms. [larger version]

Galveston, TX

Updated assessment of inundation potential (storm surge minus dune elevation) for Galveston, TX using modeled storm surge based on Hurricane Ike storm conditions and landfall location. In most areas, severe inundation (red colors) and coastal change are expected as the updated surge estimates exceed the elevations of the primary dunes/berms. [larger version]

Chenier Plain, LA

Updated assessment of inundation potential (storm surge minus dune elevation) for the southwest Chenier Plain, LA using modeled storm surge based on Hurricane Ike storm conditions and landfall location. In most areas, severe inundation (red colors) and coastal change are expected as the updated surge estimates exceed the elevations of the primary dunes/berms. [larger version]

Isles Dernieres, LA

Updated assessment of inundation potential (storm surge minus dune elevation) for the Isles Dernieres, LA using modeled storm surge based on Hurricane Ike storm conditions and landfall location. Moderate to severe inundation (yellow to red colors) and extreme coastal change are expected as the updated surge estimates exceed the elevations of the primary dunes/berms. [larger version]

Initial Assessment of Potential Coastal-Change Impacts (posted 09/10/08)
USGS

Storm-Impact Scale
USGS

Storm-Induced Coastal Change
USGS

USGS Mendenhall Postdoctoral Research Fellowship
USGS