Landsat TM-based analysis of land area and vegetation cover change on six selected Alabama and Mississippi barrier islands (1984-2011).

摘要

Cat Island, West Ship Island, East Ship Island, Horn Island, Petit Bois Island, and Dauphin Island are located 10-20 kilometers south of the Mississippi and Alabama coastlines. These six barrier islands serve as an important shield to southern areas of Mississippi and Alabama from tropical cyclone (hurricane) impacts such as storm surge and destructive waves. The islands are also home to a delicate ecosystem of many different types of flora and fauna. Over the course of the past three decades, all six islands have been subjected to several hurricane events. This, coupled with the natural state of the erosion, has led to the islands losing total land area and vegetation. This thesis research focuses on quantifying the vegetation loss and total land area loss on Cat Island, West Ship Island, East Ship Island, Horn Island, Petit Bois Island, and Dauphin Island during the time period from 1984 to 2011. A special focus is given to impacts of Hurricanes Georges, Ivan, Katrina, Gustav, and Ike which affected the northern Gulf Coast in 1998, 2004, 2005, and 2008, respectively. This research utilizes Landsat 5 Thematic Mapper Imagery. Supervised classifications and Normalized Difference Vegetation Index (NDVI) analyses are performed on each scene to analyze the total land area and vegetation cover of each island. The results of this research show the total extent of land and vegetation loss on each island from 1984 to 2011, and which islands are most vulnerable to erosion and vegetation loss. The results also reveal how all five hurricanes affected each individual island.