Interaction of Shock Waves with Tree Crowns and the Front of Crown Forest Fires

Abstract

Fires are known to cause great damages to forests all over the world. Traditional ways of extinguishing town fires by water or by various chemical compositions are not effective in localizing and extinguishing forest fires, as the form of the fire front changes with time and its thickness is considerably less than its length. Besides, forest fires as a rule take place in almost inaccessible places, and supplying large masses of water to the front of a forest fire by ground transport is hampered, while throwing out water masses from safe flight altitudes is not efficient.

In this connection, a new concept of fighting forest fires by means of relatively small energetic effects on the fire front is proposed (Grishin 1992). Specifically, it is proposed to use relatively weak shock waves, more or less harmless to the trees themselves.

In the present paper a review of experimental and theoretical results is presented on the interaction of shock waves with tree crowns and the forest fire front, which have been obtained by the research workers of the Tomsk State University during a period of five years.