Document Actions
Technology development to support a national early warning system for environmental threats
PARTNERS: NASA Stennis Space Center; Oak Ridge National Laboratory; University of North Carolina Asheville’s (UNCA) National Environmental Modeling and Analysis Center; USGS EROS Data Center; USDA Forest Service Western Wildland Environmental Threat Assessment Center, Forest Inventory and Analysis, Forest Health Monitoring, Forest Health Technology Enterprise Team, and Remote Sensing Applications Center
SUMMARY: The early warning system (EWS) is an ongoing monitoring project that detects forest threats across the continental United States using remote sensing and geographic information systems. The tool will help forest managers identify large scale forest changes faster, allowing them to use traditional methods to confirm and determine the nature and severity of the forest threat.
EFETAC's ROLE: EFETAC is contributing the design concept, development, sponsorship, production management, interpretation, and technology transfer.
STATUS: Ongoing
PROGRESS: Scientists and collaborators have established a prototype forest national early warning system by producing maps showing potential forest disturbance across the conterminous United States at 231-meter resolution every 8 days, based on images obtained over the preceding 24-day analysis window. Potential disturbance maps are obtained by comparing historical expectations of normal vegetation greenness with greenness from a series of current satellite views.
Three disturbance products have been developed, using differing lengths of historical baseline periods to calculate the expected normal greenness. The long-term baseline products show all disturbances over the MODIS satellite imagery historical period, while the intermediate baseline products show disturbances since the prior three years. The short-term baseline products show only disturbances newer than one year. The disturbance maps were made available to sketchmappers for the first time in 2010.
The Forest Change Assessment Viewer is a prototype website that showcases recent national disturbance maps in spatial context. The EWS proved especially useful for mapping disturbances during the 2011 growing season. Although all but forest vegetation is usually masked out of disturbance maps, the EWS detects and tracks disturbances in all vegetation, including potential disturbances in rangeland vegetation and agricultural crops.
The year 2011 was remarkable in terms of climate anomalies and forest disturbances. The tropical condition known as La Niña contributed to extreme drought conditions across much of the south central and southeastern United States. This drought was particularly strong in Texas where western portions of the state experienced extreme drought that led to a record outbreak of wildfire and a sharp decline in rangeland productivity. Large and long duration fires also occurred from the Ponderosa pine forests of eastern Arizona to the peaty forests of the coastal plain of Florida, North Carolina, and Virginia. With a few notable exceptions, the entire northern tier of the United States experienced few wildfires in 2011.
Earlier in the spring, unusual cold and wet conditions across the West and Northeast were in the news. An abnormally heavy winter snowpack took time to melt which delayed Spring greenup. That late spring was followed by one of the most notable tornado outbreaks in memory, particularly in the Southeast. The EWS was used to map tornado scars from the historic April 27, 2011 tornado outbreak, and detected timber damage within more than a dozen tornado tracks across northern Mississippi, Alabama, and Georgia. Many human lives were lost and many trees were toppled in these historic events.
Defoliating insects were prevalent across the United States during 2011. Particularly noteworthy examples of defoliation occurred in the bald cypress forests of Louisiana; the ponderosa pine forests of western South Dakota; the pine and fir forests of Montana, Idaho, and Washington; the northern hardwood forests of northwestern Pennsylvania; and in the hemlock-dominated forests of several states in the central and southern Appalachians.
LINKS:
UNCA's National Environmental Modeling and Analysis Center
Western Wildland Environmental Threat Assessment Center
Forest Health Technology Enterprise Team
Remote Sensing Applications Center
CONTACT:
Bill Hargrove, EFETAC Ecologist, whargrove@fs.fed.us or 828-257-4846
Updated January 2012
