Land Area Changes in Coastal Louisiana after the 2005 Hurricanes: Marsh Communities
The 2004 and 2005 land-water data sets were combined with a data set containing 2001 marsh vegetation community types in order to identify new land-water changes within marsh communities. The greatest water area increases were in the fresh marsh community (316 km2) and the intermediate marsh community (233 km2). Lesser water area increases occurred in the brackish marsh community (85 km2) and the saline marsh community(73 km2). Remnant surge flooding caused some of the increased water area in the fresh and intermediate marsh communities. However, fresh and intermediate marsh communities located near to or east of the hurricane landfalls experienced detectable surge shearing at Landsat TM spatial resolutions. Brackish and saline marsh communities appear to be more resilient to shearing than fresh and intermediate marsh communities.
The purpose of this analysis was to provide preliminary information on land area changes shortly after Hurricanes Katrina and Rita. Estimation of permanent losses cannot be made until several growing seasons have passed and the transitory impacts of the hurricanes are minimized.