Monday, 17 November 2003
A risk index for mediterranean vegetation based on micrometeorological and ecophysiological measurements
Many fire risk models have been developed for various temporal and spatial scales and application purposes. Forest fire risk is being evaluated from several perspectives, which take into account the variability of the input layers in time. Those indices that are derived from factors that do not change in a short lapse of time are referred to as static or structural indices. On the contrary, the dynamic indices are derived from factors that vary in short period of time, such as the vegetation status or the mereorological conditions. Indices that include structural and dynamic variables can also be computed and they are called integrated or advanced indices. In this paper an integrated and specific forest fire index for Mediterranean ecosystems (IFI) is presented. This integrated forest fire index (IFI) was developed to be included into an operational warning system managed by the Regional Weather Service of Sardinia, Italy. The IFI index is based on micrometeorological or meteorological measurements, ecophysiological observations and topological data related to local environmental conditions and vegetation type and structure. The IFI index derives from four components or relative numerical ratings which take into account individual and combined factors that determine the level of fire risk. In particular, IFI includes (i) a Drought Code describing the water status of vegetation, (ii) a Fuel Code related to fuel type and vegetation structure, (iii) a Micrometeorological or Meteorological Code which includes turbulence field data or weather data, and (iv) Topological Code which is a descriptor of site topography and prevailing synoptical conditions. The IFI index was evaluated analysing its performance for several fire events occurred in Sardinia and the results were compared with those obtained from different forest fire risk index commonly used.