Wild fires have a significant impact on vegetation dynamics. They are a major disturbance to the boreal ecosystem and contribute to the increase in trace gases that cause variations in climate. Fires also deplete timber resources so that monitoring forest fires is a critical aspect of sustainable forest management.

Figure 1a - Fire Detection Image Full image 139Kb jpg June 25, 1995

Using NOAA-11 and NOAA-14 AVHRR images, researchers in the Environmental Monitoring Section, CCRS, have developed algorithms to identify actively burning forest fires. These could be used to provide daily satellite-based fire monitoring for Canada. The algorithms take advantage of information from multi-channel AVHRR measurements to determine the locations of active fires on satellite images (with pixels of about 1 km2) under clear sky or thin cloud conditions. Figure 1a is an example of an image showing forest fires across Canada detected by the NOAA-14 satellite on June 25, 1995. Smoke plumes from fires are clearly seen from AVHRR channel-1 measurements (background) and burning areas (red spots) are detected by the computer algorithm. Zoom-in images are available for the three regions indicated.

Figure 1b - Site #1 1 in QC Also available: Subarea #2, Man 17Kb jpg Subarea #3, NWT 9Kb jpg

The algorithms were applied to a data set containing more than 600 Canada-wide NOAA/AVHRR daily mosaics for the 1994, 1995, 1996 and 1997 fire seasons. The resulting product (Figure 1b) permits a daily view of the situation for active fires across Canada.

Figure 2 1994-1997 Fire Overview Full image 168Kb jpg 1994-1997 Overview

Figure 2 combines individual daily fire masks to give an overview of the detected forest fires across Canada throughout the entire burning season for the four years (1994-1997). Data from the 1995 yearly fire mask were compared to data obtained by two Canadian fire detection agencies.

Figure 3 Subarea #3, NWT A = Detected from satellite B = Conventional methods

Figure 3 shows (in red) the pixels marked as active fire during the 1995 fire season for a portion of the Northwest Territories (Subarea #3). The blue outlines indicates the boundaries of the burnt areas as observed by fire agencies using conventional means of monitoring. It can be seen that the satellite-based technique does a better job, detecting more fires than the traditional method at much less cost.

Figure 4 Fire Evolution in 1995 Subarea #3, NWT

Satellite monitoring can also provide information on the evolution of fires as they develop. Fire evolution for 1995 in the Northwest Territories is displayed in Figure 4. Each colour represents a 10 day period of active fire in that location.

Li, Z., J. Cihlar, L. Moreau, F. Huang, B. Lee, Forest fires around the BOREAS region in 1994: In-situ and remote observations, Journal of Geophysical Research.