1983年4月27日岩手県久慈市の林野火災拡大化に及ぼした風と地形の効果について

Abstract

The effects of wind and topography on the large forest fire occurred in Kuji area on April 27 isstudied based on the field survey of the damaged area. The main direction of the fire spread wascontrolled by the average wind direction for the Kuji area, but the detailed spreading was found tobe affected considerably by the small scale topographies. The fire spreading velocities are largercompared to those in the past large forest fires, although they are the expected values consideringthe large wind speed. The existence of the bay shape valley or the valleys extending perpendicularto the wind direction are found to have significant effects on large fire expansion, flight of firebrand and formation of the fire induced vortices.