Hurricane Katrina and New Orleans: Subsidence Measurements from Space

Timothy H. Dixon

University of Miami, Florida

It has long been recognized that New Orleans is subsiding, potentially leading to catastrophic flooding. A new subsidence map for New Orleans based on space-based Synthetic Aperture Radar (SAR) shows high subsidence rates in parts of New Orleans, including levees adjacent to the MRGO canal that failed during Hurricane Katrina.  This gives clues to the failure process: these levees may have been overtopped during peak storm surge due to subsidence of ~ 1 meter or more since levee construction, or high subsidence rates may indicate a weak substrate beneath the levees.