A Satellite Index of Risk of Forest Fire Occurrence in Summer in the Mediterranean Area

Abstract

An index of forest fire risk has been determined by using the vegetation index NDVI and the surface temperature Ts, computed from NOAA-AVHRR over 21 Mediterranean French forests. Those 2 satellite parameters can be interpreted in terms of soil water deficit and vegetation stress in summer. An inverse linear correlation between their values for each forest pixel of 10 dates in 1990 was used to establish the index which has been divided into 5 equal classes. Those classes correspond with 5 risk classes of forest fire occurrence which were mapped for several forests. Periods and areas in the highest risk class correspond with those where the most important number of fires appeared in that year for the studied forests. A statistical model of the period of highest fire risk has also been constructed for each forest.