Mapping sub-pixel burnt percentage using AVHRR data. Application to the Alcalaten area in Spain

Abstract

The purpose of this work is to estimate at sub-pixel scale the percentage of burnt land using the Advanced Very High Resolution Radiometer (AVHRR) through a simple approach. This methodology is based on multi-temporal spectral mixture analysis (MSMA), which uses a normalized difference vegetation index (NDVI) and a land-surface temperature (LST) image as input bands. The area of study is located in the Alcalaten region in Castellon (Spain), a typical semi-arid Mediterranean region. The results have shown an extension of approximately 55 km² affected by fire, which is only 5% lower than the statistic reports provided by the Environmental Ministry of Spain. Finally, we include a map of the area showing the percentage of estimated burnt area per pixel and its associated uncertainties. The map was validated through supervised classification of an Airborne Hyperspectral Sensor (AHS) image taken on 27 September 2007. Results have a high accuracy, with a mean error of 6.5%.

Acknowledgements

We would like to thank the ESA for contributing with the CEFLES project and the Spanish Ministry of Education for the TERMASAT project. This work was also supported in part by the Generalitat Valenciana by means of the grants for postdoctoral researches in centres of the Comunidad Valenciana. The authors would like to thank the Ministry of Environment, especially J. Merida for his kind answers to our needs. We would also like to thank the European Union for EAGLE, project SST3-CT-2003-502 057.