Rapid Assessment of Storm-Surge Inundation After Hurricane Katrina Utilizing a Modified Distance Interpolation Approach

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Geography and Geology


This study developed a method to rapidly assess, during early mitigation planning and recovery efforts, both the flood extent and the water depth of Hurricane Katrina's storm surge. Over a hundred high water marks were collected within the Mississippi Gulf Coast study area utilizing survey equipment and GPS measurements. In order to account for the many inlets and estuaries along the coast, an interpolation approach was tested that allowed the interpolation algorithm to calculate distance around such barrier features rather than directly through them, thus more appropriately modeling the physical process of water distribution during the storm surge event. This technique was implemented operationally using a "cost surface" algorithm, available in most GIS software packages. A binary impedance surface (travel is either possible or not) was utilized as input to the cost surface algorithm. The impedance surface was generated using modified hydrologic operations on an existing lidar-derived DEM. This technique is detailed. The water surface generated from these points more closely matched the reference surface than those of comparable surfaces generated using tradition interpolation techniques. The reference datasets for this project consisted of FEMA flood inundation and water surface maps released a few months after the datasets created for this project.

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Giscience & Remote Sensing





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