Fire Scars Area Estimation using CHRIS PROBA Satellite Data
Filchev, Lachezar; Dimitrov, Petar

The dawn of 21st century is marked by severe and unpredictable natural and man-made hazards and disasters linked as to climate change as to human impact on environment. To study their effects on natural landscapes and protected areas it is important to perform, in some restrict regime protected areas, a continuous monitoring. Earth observation by satellites is one of the most promising instruments for this as it has the necessary time, spatial, and spectral resolution for this as well as it provides for non-contact estimation of the overall condition of the environment. This study presents preliminary results of fire scars area estimation on the territory of "Bistrishko Branishte" UNESCO MAB biosphere reserve in Vitosha Mountain, Bulgaria using CHRIS PROBA satellite data. During the summer and early autumn of 2012 CHRIS PROBA instrument was tasked to perform subsequent acquisitions with a view to study the vegetation structure and to correlate spectral and LAI data to the satellite images. The study uses two CHRIS PROBA scenes acquired subsequently on 22 June 2012 and on 28 September 2012. The wildfire, which effects are studied, took place during the first two weeks of July 2012 and was resumed in late autumn of 2012. After it was settled the second acquisition of CHRIS PROBA instrument made possible the analysis of the post fire situation after the first fire outbreak. The methods used for the study are the standard methods for change detection based on spectral data employed in ENVI software (Academic license). In order to perform the change detection, the CHRIS PROBA source data was geometrically and atmospherically corrected as well as co registered. Topographic normalization was performed on the second image due to the casted shadows on the burned slopes of Bistrica river valley. The multiangle product of CHRIS PROBA was used to check to what extent the five viewing angles affect the area estimation of the fire scars following the same procedures. The results from the analysis shown that almost 60 hectares from the coniferous vegetation (dead and healthy tree stands) were devastated by the wildfire.