Sergio Bernardes Center for Geospatial Research – University of Georgia
Marguerite Madden Center for Geospatial Research – University of Georgia
Thomas Jordan Center for Geospatial Research – University of Georgia

14F

This work builds upon our previous investigation on using multi-scale remote sensing to assess vegetation status and damage following hurricanes in Sapelo Island, Georgia coast. Here, we expand the spatial domain of that study to map and analyze instances of vegetation disturbance/damage along the entire coast of the state of Georgia, United States. Due to their intensity, impacts associated with hurricanes often include drastic alterations of physical and chemical environmental conditions that sustain key coastal ecosystems. Hurricanes can totally or partially remove vegetation (e.g., uproot trees and/or break trunks and limbs), change salinity of water available to root systems, increase exposure of aerial parts to salt spray, and change the spatial distribution of sand dunes and associated biota. Climate projections suggest that hurricanes, such as those that have affected the United States in recent years, may become more frequent and intense, resulting from the warming of ocean waters and the atmosphere. This work uses remote sensing tools and techniques to create a pre-hurricane baseline of vegetation status and investigates changes in vegetation in areas that have been recently affected by hurricanes. Analyses included change detection at the region using time series of co-registered Sentinel 2 and Landsat images. We integrate results from our field campaign at Sapelo Island in September 2017, including images collected by our UAVs over the island (high-overlap, 1 and 2 inches/pixel RGB images; five-band multispectral). Images represent multiple vegetation types, including healthy vegetation and vegetation affected by storm surge and spray during a hurricane event. Drone images covering over 600 acres were then analyzed for vegetation status and damage, with emphasis to vegetation removal and browning resulting from salinity alterations and salt spray. Results from images acquired by drones were then scaled-up to Sentinel 2 spatial/spectral resolutions and tested using a control area. The work uses our evaluation of limits of detectability of vegetation damage using orbital systems (Sentinel 2) and addresses changes in damage over space and time along the Georgia coast following hurricanes.

14:00 A Spatiotemporal Analysis of Vegetation Browning Following Recent Extreme Events on the Georgia Coast, Marguerite Madden