Evaluating and comparing Sentinel 2A and Landsat-8 Operational Land Imager (OLI) spectral indices for estimating fire severity in a Mediterranean pine ecosystem of Greece

• Published in: GIScience and remote sensing Vol. 55; no. 1; pp. 1 - 18
• Main Authors: Mallinis, Giorgos, Mitsopoulos, Ioannis, Chrysafi, Irene
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 02.01.2018; Taylor & Francis Group
• Subjects: burn severity; CBI; dNBR; ecosystems; fire severity; forest fires; GeoCBI; Greece; Landsat; Mediterranean region; medium spatial resolution; normalized difference vegetation index; remote sensing; Greece; Mediterranean region
• ISSN: 1548-1603; 1943-7226; 1943-7226
• DOI: 10.1080/15481603.2017.1354803

The main purpose of this study is to explore the relationship between three field-based fire severity indices (Composite Burn Index-CBI, Geometrically structure CBI, weighted CBI) and spectral indices derived from Sentinel 2A and Landsat-8 OLI imagery on a recent large fire in Thasos, Greece. We employed remotely sensed indices previously used from the remote sensing fire community (Normalized Difference Vegetation Index (NDVI), Normalized Burn Ratio (NBR), differenced NDVI, differenced NBR, relative differenced NBR, Relativized Burn Ratio) and seven Sentinel 2A-specific indices considering the availability of spectral information recorded in the red-edge spectral region. The statistical correlation indicated a slightly stronger relationship between the differenced NBR and the GeoCBI for both Sentinel 2A (r = 0.872) and Landsat-8 OLI (r = 0.845) imagery. Predictive local thresholds of dNBR values showed slightly higher classification accuracy for Sentinel 2A (73.33%) than Landsat-8 OLI (71.11%), suggesting the adequacy of Sentinel 2A for forest fire severity assessment and mapping in Mediterranean pine ecosystems. The evaluation of the classification thresholds calculated in this study over other fires with similar pre-fire conditions could contribute in the operational mapping and reconstruction of the historical patterns of fire severity over the Eastern Mediterranean region.