2009 Research Highlights
Early warning system detects seasonal vegetation changes
The early warning system is an ongoing monitoring project that detects forest threats across the continental U.S. using remote sensing and GIS. Through the use of multi-temporal change detection, the system is designed to assess landscape and forest change over a broad geographical area. A core element of the early warning system is NASA’s MODIS (Moderate Resolution Imaging Spectroradiometer) satellite imagery, which provides worldwide imagery coverage captured at 1 to 2 day intervals. MODIS is especially useful for threat detection due to its frequent revisits, broad spectral capabilities, and large image swath. These advantages allow for the creation of cloud free 16-day composites on a continental scale.
The Eastern Forest Environmental Threat Assessment Center is partnering with NASA’s Stennis Space Center to produce a series of seamless, CONUS phenology (seasonal changes in vegetation) datasets derived from MODIS imagery. The phenology image data includes normalized vegetation index maps for assessing plant and forest conditions. Currently, the 16-day intervals from 2002-2008 are complete. Online viewers for the data will soon be available for remote public access.
The early warning system will use the phenology data in its change detection models for identifying forest threat locations and tracking patterns of progression. In preliminary studies, the data has already proved to be very effective for hurricane assessment along the gulf coast and for identifying forests affected by gypsy moth. As the early warning system reaches a fully operational status, the data will be assessed for each succeeding 16-day period. Forest threat locations revealed with the MODIS derived phenology data will then make it possible for further analysis using higher resolution imagery and data.
Contact: William Hargrove, ecologist, (828) 257-4127, william.w.hargrove@usda.gov or Stephen Creed, GIS specialist, (828) 259-0544, stephencreed@fs.fed.us
Partners: USDA Forest Service Forest Inventory and Analysis; USDA Forest Service Forest Health Monitoring; International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forest; NASA Stennis Space Center; University of North Carolina Asheville’s National Environmental Modeling and Analysis Center
