The relation between the moisture content of fine forest fuels and several forest fire related aspects

Abstract

The relations between the forest fuels moisture content and the meteorological data (or their derived indices), the fire occurrence or the burned area, are very important in terms of forest fire research. The measurement of the moisture content of the living and dead tree foliage from Pinus pinaster and Eucalyptus globulus was performed i n Viseu (Central Portugal), between April and June 2005. The samples were collected in a south - facing slope, between 12.00 and 13.00 Local Standard Time and their moisture content was obtained following an oven drying period of 24 h ours . A good empirical r elation was obtained between the moisture content of both species dead samples. The moisture content of the studied species was compared with the three fuel moisture indicators of the Canadian Forest Fire Danger Rating System (Fine Fuel Moisture Code, Duff Moisture Code and Drought Code) concerning the Viseu meteorological station, with good relations being obtained for the dead samples. The dead samples moisture content also showed good relations when compared with the statistical data, concerning the dail y fire occurrence and burned area in the Viseu d istrict during the same period. The indicators of the Canadian Forest Fire Danger Rating System concerning the Viseu meteorological station were compared with the statistical data, concerning the daily fire o ccurrence and burned area in the Viseu d istrict. The obtained empirical relations showed good results for the Fine Fuel Moisture Code, the Initial Spread Index and the Fire Weather Index.