Characterization of the Australia’s 2019 megafires: a remote-sensing perspective

Abstract

The 2019/20 bushfires in Australia were the most catastrophic event in the country’s history, inflicting extensive damage to ecosystems, infrastructure, and more. Extensive research has been conducted to ascertain the causes, which were exacerbated by a severe 3-year drought and subsequent heatwaves. The current study focuses on analysing satellite data to investigate changes in surface characteristics across large burned areas spanning various land covers in Eastern Australia. Specifically, the study aims to track surface property changes over a period, encompassing 1 month preceding and 1 month following the onset of fire events. In addition to analysing vegetation and climatic variables, surface roughness was computed and examined, revealing decreases over the study period. There was a spatially consistent decrease across all surface properties (Soil Moisture, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), Albedo and Surface Roughness) in forests, indicating a widespread pattern of change irrespective of location. An examination of the impact of fire severity revealed consistent patterns of decreasing surface property values (LAI, EVI, NDVI, albedo, and surface roughness) with increasing fire severity. This study underscores the crucial role of optical/infrared remote sensing in monitoring and assessing the ecological impacts of bushfires. By examining the complex relationships between fire, climate, and vegetation, our research provides new information on the characterization of 2019/20 megafires across different landcovers.