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.