Suivi, par imagerie NOAA-AVHRR, de l'état hydrique de peuplements de conifères du bassin du fleuve Mackenzie (Territoires du Nord-Ouest) dans une perspective de prévision du danger d'incendie de forêt

Abstract

In Canada, forest fire hazard and fire behavior are evaluated on a daily basis by the Canadian Forest Fire Danger Rating System (CFFDRS). One of the inputs into this system is the foliar moisture content which is calculated indirectly from elevation, latitude, longitude and date. To investigate the potential applicability of satellite remote sensing to follow this variable, the foliar moisture content was measured in situ with samples of needles taken weekly during the 1994 forest fire season from white spruce, black spruce and jack pine stands located on seven sites along the Mackenzie River (Northwest Territories). The foliar moisture content measurements were then expressed in relation to the normalized difference vegetation index (NDVI) and the difference between surface and air temperature (Ts-Ta), derived respectively from optical and thermal NOAA-AVHRR images acquired on the same dates as the foliar moisture content measurements. In all cases, the estimated foliar moisture content values obtained from the satellite data were better than those derived from the CFFDRS."--Résumé abrégé par UMI.