Forest fires began soon after terrestrial plants appeared and have kept breaking out throughout the history. Each year, an average of 200,000 forest fires take place around the globe, damaging more than 1‰ of the world’s total forestry area. However, it is generally difficult to detect the flame in a timely manner, hence serious damages and losses when it runs out of control.
The burnt area is a fundamental factor to evaluate a forest fire, referring to the total area that the blaze has raged, regardless of its intensity. It is an indicator of the disaster’s influence upon the vegetation and eco-environment.
Therefore, timely and accurate monitoring and positioning of fires are crucial, given the presently high-cost, poor time-efficiency and low-intensity of man and aircraft monitoring on the ground.
A New Solution
The Satellite RS technology owns qualities of a short imaging period and a wide coverage, highly applicable for forest fire detection and burnt area reckoning.
After a forest fire, the spectral traits of the ground truth will be distinctly altered. The burnt ones will be darker and deeper in color, contributing to an apparently decreased spectral reflectivity at the visible spectral band. By contrasting the pre and post-fire vegetation coverage, the solution establishes a reckoning mode and calculates meticulously the affected area.
We’ve selected the border regions between China and Russia for a 4-phase data extraction of the burnt area covering 457,369 square kilometers. After a pretreatment of images (radiometric and atmospheric calibration, perpendicular shooting, merging and clipping), we made an intelligent extraction of the burnt area.
Images of burnt area distribution are shown below:
(1) Burnt area distribution at China-Russia borders on March 21, 2017.
（2） Burnt area distribution at China-Russia borders on April 13, 2017.
（3）Burnt area distribution at China-Russia borders on April 22, 2017.
（4）Burnt area distribution at China-Russia borders on April 29, 2017.