Los Alamos Before and After the Fire On May 4, 2000, a prescribed fire was set at Bandelier National Monument, New Mexico, to clear brush and dead and dying undergrowth to prevent a larger, subsequent wildfire. Unfortunately, due to high winds and extremely dry conditions in the surrounding area, the prescribed fire quickly raged out of control and, by May 10, the blaze had spread into the nearby town of Los Alamos. In all, more than 20,000 people were evacuated from their homes and more than 200 houses were destroyed as the flames consumed about 48,000 acres in and around the Los Alamos area. The pair of images were acquired by the Enhanced Thematic Mapper Plus (ETM+) sensor, flying aboard NASA’s Landsat 7 satellite, shortly before the Los Alamos fire (top image, acquired 14 April 2000) and shortly after the fire was extinguished (lower image, 17 June 2000). The images reveal the extent of the damage caused by the fire. Landsat 7 data courtesy United States Geological Survey EROS DataCenter. Images by Robert Simmon, NASA GSFC. 1 Burn scar after a high intensity stand-replacement fire in a northern boreal coniferous forest (Pinus banksiana), North West Territories, Canada. The fire scar is irregular and produces a distinct forest landscape mosaic. The mosaic pattern is created by landscape features such as water bodies, depth of organic terrain, soil moisture, elevation and slope, and the history of previous disturbances by fire. 2 Similar effect of a high-intensity fire in a boreal Scotch Pine (Pinus sylvestris) fire in Eastern Siberia. Immediately after the burn the black-coloured area represents the stands affected by crown fire. The brown parts represent scorched crowns. I a later stage (several months after the fire) the scorched needles are shed, and both types of fire affected areas look similar from space. Those portions of the forest stands which had been affected by low- to medium-intensity surface fires which have not affected the crown layer are difficult to detect from space. 3 Fire scars in a boreal forest in Central Siberia. The scars were created by one single fire. The different optical (and spectral) characteristics are due to non-homogeneous disturbances by logging before the fire. 4 Post-fire scene of a typical forest clearing (forest conversion) area in a tropical rain forest. Depending on seasonal drought and preparation of the conversion area by clearcutting, the first burn is often not complete and requires a second or third burn. Heavy logs are often consumed by fires burning many days after the initial burn. The fire scar is easily visible from space. 5 Fire scar in an East African grass savanna (Tanzania). The irregular shape of the burn scar is typical for most savanna burns in Africa. A variety of effects are responsible for irregular fire spread: Fragmentation of savanna landscape by land use, effects of intensive utilization of phytomass by grazing of wildlife and domestic animals, trampling, topographic features, water bodies and soil moisture. Changing weather conditions and daytime of burning also create a high degree of variability in fire behaviour and spread. 6 Experimental savanna fire in an East African grassland (Kenya). The burn plot is situated between fire breaks and allows to produce a well-delineated fire scar for satellite instrument validation purposes.