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Oil detection and latent impact monitoring in coastal marshes with polarimetric SAR

Elijah Ramsey, USGS National Wetlands Research Center,
Amina Rangoonwala, Five River Services, LLC,
Cathleen Jones, Jet Propulsion Laboratory, (Presenter)
Benjamin Holt, Jet Propulsion Laboratory,

Ongoing losses of coastal wetlands in the northern Gulf of Mexico are accentuated by hydrologic modifications, lack of sediment replenishment, and storm impacts. The widespread and often severe impacts of Macondo-1 oil from the Deepwater Horizon spill to the shoreline marshes of northeastern Barataria Bay, Louisiana, raised concern that oil contamination and the subsequent clean-up could intensify marsh degradation and loss; there was an immediate need to identify what marsh was contaminated, how severely, and to track impact and restoration. In response to that need, NASA/JPL and USGS are collaborating in a TE-ROSES2011-funded proposal to apply L-band high resolution polarimetric synthetic aperture radar (PolSAR) to detecting oil in marshes based on the differing dielectric constants of oil and water. Starting during the 2010 oil spill and extending through 2012, NASA’s UAVSAR quad-POLSAR sensor imaged coastal Louisiana while teams collected ground data to support PolSAR data interpretation. Here we discuss the remote sensing methods we developed to detect oil and monitor latent change within the coastal marshes of eastern Louisiana known to have been heavily impacted by the DWH spill. Our oil detection algorithm relies on decomposition and classifications of pre-spill 2009 and post-spill 2010 PolSAR scenes. We found significant change in the Freeman-Durden and Cloude-Pottier decompositions' derived dominant scatter mechanism associated with oiled shorelines and within a spatially extensive class of interior marshes. In support of the TE-ROSES proposal, field collections to document oil impact along shorelines and in interior marshes were undertaken to ascertain whether these changes could be directly related to ground-level oiling from the DWH spill. In addition, we have measured the shoreline loss in heavily oil-impacted and remediated marshes from both steady state decline in 2010 - 2012 following the impact and from storm-induced rapid loss during Hurricane Isaac.

Presentation Type:  Poster

Session:  Poster Session 2-A   (Wed 11:00 AM)

Associated Project(s): 

Poster Location ID: 51


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