Fire danger monitoring using RADARSAT-1 over northern boreal forests

The goal of this study was to evaluate the potential use of RADARSAT-1 images to assess daily variations in dead fuel moisture over a northern boreal forest area, as parameterized by the Canadian Forest Fire Weather Index (FWI) System. The study area was located in the south-central region of Canada's Northwest Territories and was comprised of three land cover classes ( mature forest, burned forest, and fireguard areas). Nineteen RADARSAT-1 images were acquired over the study area in June 2000 and August 2002, and their backscatter was compared to weather data and to the FWI System components. In both cases, the influences of incident angle and land cover class were measured. Radar backscatter was related to rainfall, and strong relationships were observed with the FWI System codes and indexes, particularly for Duff Moisture Code (R-2=0.68-0.83), Drought Code (R-2=50.77-0.82), Build- up Index (R-2=0.72-0.86), and FWI (R-2=0.62-0.85). The best regression models were obtained using a stepwise regression procedure in which radar backscatter from the burned forest was used as the independent variable.