Quantifying the Impact of Hurricanes, Mid-latitude Cyclones and Other Weather and Climate Extreme Events on the Mississippi-Alabama Barrier Islands using Remotely Sensed Data

• Main Author: Jones, Rebekah Danielle
• Other Authors: Sylvester, Judith
• Format: Others
• Language: en
• Published: LSU 2014
• Subjects: Geography & Anthropology
• Online Access: http://etd.lsu.edu/docs/available/etd-03312014-165620/

Recent high-profile hurricanes have demonstrated the destructiveness of extreme events on coastal landscapes to the world. Barrier islands across the planet are disappearing, exposing vulnerable coastal cities to the damage caused by extreme events. Growing resolve among scientists regarding climate change's connection to tropical cyclones heightens the concern around intensifying extremes and landscape dynamics. This study uses more than 600 Landsat images to examine the role of extreme events on barrier island morphology on four of the Mississippi-Alabama barrier islands from 1972-2014. Each island, West Ship Island (WSI), East Ship Island (WSI), Petit Bois Island (PBI), and Sand Island, was measured for area in hectares (ha) 14 times per year on average with higher temporal resolution before and after hurricanes, allowing for a high-resolution statistical history of surface area change and the quantification of the impact of extreme weather events. The results reveal that extreme events, specifically hurricanes, mid-latitude cyclones, and thunderstorms, shape the islands more than gradual erosion and accretion processes across all islands. The results also show that hurricanes trigger accelerated erosion beyond landfall. Catastrophic events caused 54-59% of all land area change on the islands during the study period. Hurricanes caused 26-37% of all change across the islands, thunderstorms 11-13%, and mid-latitude cyclones 11-14%. Three of the islands lost at least one-quarter of their 1972-1973 areas: WSI 25%, ESI 39%, and PBI 38%. WSI, ESI, and Sand Island are all in post-Katrina (2005) regrowth periods while PBI has destabilized and continues to experience net erosion. The results of this study can serve the Gulf Islands National Seashore in long-term environmental planning.