REMOTE SENS. ENVIRON. 45:61-71 (1993) Monitoring of Wildfires in Boreal Forests Using Large Area AVHRR NDVI Composite Image Data Eric S. Kasischke and Nancy H. F. French Center for Earth Sciences, Environmental Research Institute of Michigan, Ann Arbor Peter Harrell and Norman L. Christensen, Jr. School of the Environment, Duke University, Durham Susan L. Ustin Department of Land, Air and Water Resources, University of California, Davis Donald Barry Alaska Fire Service, U.S. Bureau of Land Management, Fairbanks Normalized difference vegetation index (NDVI) However, the total area contained within the fire composite image data, produced from A VHRR data boundaries mapped by A VHRR were only 61% of collected in 1990, were evaluated for locating and those mapped by the field observers. However, the mapping the areal extent of wildfires in the boreal A VHRR data used in this study did not span the forests of Alaska during that year. A technique entire time period during which fires occurred, and was developed to map forest fire boundaries by it is believed the areal estimates could be improved subtracting a late-summer A VHRR NDVI image significantly if an expanded A VHRR data set were from an early summer scene. The locations and used. boundaries of wildfires within the interior region of Alaska were obtained from the Alaska Fire Ser- INTRODUCTION vice, and compared to the AVHRR-derived fire- boundary map. It was found that AVHRR detected In severe fire seasons, large areas of interior Alaska 89.5% of all fires with sizes greater than 2000 ha are burned in wildfires. The area burned during with no false alarms and that, for most cases, the the 1990 fire season in Alaska (1.28 million ha or general shape of the fire boundary detected by 12,800 km 2) was the fifth highest total since rec- AVHRR matched those mapped byfield observers, ord keeping began in 1940. A significant amount of the area burned in 1990 (and other years as well) occurred in a few large fires. Of the total Address correspondence to Eric S. Kasisehke, P.O. Box 134001, Ann Arbor, MI 48113-4001. area burned in 1990, 84% were in fires larger Received 9 March 1992; revised 3 September 1992. than 10,000 ha or 100 km 2, and almost 98% in 0034-4257 / 93 / $6.00 ©Elsevier Science Publishing Co. Inc., 1993 655 Avenue of the Americas, New York, NY 10010 61