Dr. Elijah Ramsey’s presentation was entitled Mapping the Occurrence and Spread of Marsh Dieback by Characterizing the Marsh Spectral Response at the Plant and Canopy Level with Hyperspectral and Temporal Remote Sensing Data. He explained how the Remote Sensing Team (RST) at the USGS National Wetlands Research Center (NWRC) applied satellite data to identify and explain the causes of extensive areas of severe marsh diebacks that were observed last spring in the coastal areas of Louisiana. The RST was able to map the occurrence and spread of the marsh diebacks and continue to monitor the area with the goal of detecting the onset of marsh dieback before irrevocable damage to the marsh had occurred.
Looking at leaf properties, canopy hyperspectral reflectance, and satellite broadband reflectance using Landsat 7 Enhanced Thematic Mapper (ETM+), researchers at NWRC located 4 impacted sites and 1 non-impacted site. They then collected plant samples along transects from the healthy marsh to the dead marsh. The findings showed that the leaf structure and pigmentation changed from the healthy marsh to the dead marsh. Using Landsat 7 ETM+ to study the canopy reflectance and the amount of mud to healthy green, researchers found that changes occurred in leaf optical properties. They also noticed a potential link between canopy reflectance and impact severity. They found that there was a decrease in reflectance from the dead to the healthy marsh because the greater, the less reflectance. They also connected remote sensing measurements to the changes in leaf pigments from the healthy to dead marsh. The potential of establishing a ink between canopy reflectance and impact severity seems promising. The methodology devised by this study will be used to guide future detection and remediation efforts.
Wynet Smith: Global Forest Watch, World Resources Institute
Wynet Smith, a member of the Global Forest Watch (GFW) program at World Resource Institute, presented applications of remote sensing and GIS technologies to forest monitoring projects. GFW is an international data and mapping network that combines on-the-ground knowledge with digital technology to provide accurate information about the world's forests. GFW tracks activities and actors in forest areas, monitors compliance, and provides data on the condition of the forest. GFW mapping projects include: mapping forested areas; compiling data sets on impacts of human activities on forests; mapping areas most threatened; and identifying roads and clearcuts. GFW maps can be used for conservation biology projects to determine whether the remaining forest resources of an area are large enough to sustain ecosystem functions; to be used as a wildlife corridor; and to preserve biodiversity.
GFW has interactive GIS-based maps on their website. The maps allow the user to select datasets such as political boundaries, water bodies, and county lines, for a specific part of the world, and overlay them with forestry data such as blocks of intact forest or forestry company licenses. There is also a query function to get more information on certain areas.
Ms. Smith also discussed the challenges and costs of this technology. Obtaining country maps created from satellite data is very expensive, ranging from $50,000 million for a large country and $2 million for a small country, even if the data is free. Creating maps from satellite data is extremely resource intensive and cannot stand alone, but must be combined with efforts such as GIs mapping and ground-truthing.
Ms. Miglarese noted that, in her experience, the main problem with remote sensing technology is that it is very difficult and expensive science and therefore not utilized very frequently at the state level. A very low percentage of the staff has been trained to use remote sensing data, and little incentive exists for state employees to learn the highly specialized and complicated technology.
However, there have been recent rapid advances in coastal research for which remote sensing has been crucial. CSC is currently implementing the Ocean Planning Information Systems project to provide the coastal management community with access to regional geo-referenced regulatory and environmental spatial data critical to timely, integrated decision making and analysis under a project referred to as. Other applications of remote sensing data include: monitoring land cover change to determine the loss of wetlands, estuaries, and forests from development; determining jurisdictional lines and to set beach setback lines; habitat mapping; and wetland permitting. CSC has also been able to use remote sensing technology to monitor algal blooms, and researchers are currently trying to develop a prediction system to forecast algal blooms.
Ms. Miglarese expressed the willingness of CSC to introduce remote sensing data as evidence in a court. Research has shown remote sensing data to be very accurate, and, once processed, not too expensive.