Short-term fire risk: foliage moisture content estimation from satellite data

A description of methods used to determine short-term changes in fire danger is reviewed, mainly those based on the estimation of foliage moisture content (FMC). Applications of low-resolution data, acquired by the Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA satellites, as well those based on high-resolution data, are examined. Examples of FMC estimation on Mediterranean areas are also presented, both for AVHRR and Landsat-TM data. In both cases, satellite data provide a higher confidence to estimate FMC in grasslands than in shrublands, although in both cases, some variables provide significant correlation, especially when the spring season is taken into account. The most sensitive variables for FMC estimation are based on short-wave infrared bands, and the combination of vegetation indices and surface temperature.