USING REMOTE SENSING OF VEGETATION STRESS TO TRACK SALTWATER INTRUSION THROUGH HIGHLY CHANNELIZED COASTAL LANDSCAPES
In flat coastal landscapes, freshwater flows typically protect vegetation along channels from the landward encroachment of saltwater. However, during extreme drought, vegetation adjacent to channels may be more vulnerable to saltwater intrusion. On the Coastal Plain of North Carolina, intensive canal and ditch networks throughout the landscape make freshwater wetlands more vulnerable to salinization. We seek to understand the role of channels in conveying saltwater into freshwater landscapes through observation of riparian vegetation using satellite remote sensing. We assessed vegetation health using indices such as NDVI, EVI, and an estimation of leaf-off date, derived from the Landsat 5 record. We then used elevation, distance to channel, and distance to coast to explain observed spatial patterns of vegetation stress. Our findings suggest that elevation, proximity to coast, and distance to channel are the most significant predictors of vegetation stress. Drought records help us to infer whether salinity or inundation is the primary driver of observed vegetation stress for a particular year. We also find that certain forest types and soil characteristics may confer more protection against salinization; these relationships should be explored further to inform wetland protection and restoration.
Justin Wright (Co-Presenter/Co-Author), Duke University, email@example.com;
Emily Bernhardt (Co-Presenter/Co-Author), Duke University, firstname.lastname@example.org;
Emily Ury (Primary Presenter/Author), Duke University, email@example.com;