Anatomy of the Las Máquinas wildfire using remote sensing tools

Abstract

The Las Máquinas wildfire took place in central Chile in the austral summer season of 2017 has becomes the most severe event in Chilean history, causing loss of life, property and the destruction of native forest, crops, large areas of commercial plantations and biodiverse habitats. Since this event has no precedent in Chilean wildfire history, it was used as an example to carry out a detailed analysis of the conditions before (pre-), during (per-) and after (post-) the fire from a remote sensing perspective. The goal of this work is to develop a framework to carry out detailed analyses of catastrophic fires for forensic and public policy purposes, making use of the advantages posed by Earth Observation satellites, including the simultaneous imaging of large areas with a good spatial resolution, and an ever-increasing temporal resolution, coupled with a sophisticated suite of instruments which allow measuring many parameters simultaneously. This study examines the biophysical, meteorological and physical variables like the evolution of the Normalized Difference Vegetation Index (NDVI), weather conditions, maximum temperature evolution, the Canadian Fire Weather Index, the burned area, the maximum fire radiative power, among others, for the five municipalities that were affected by the fire: Cauquenes, Chanco, Empedrado, Constitución and San Javier, all of which are located in the Maule Region. The results indicate that Las Maquinas wildfire took place under exceptional meteorological conditions. In particular, the conditions before the night when Santa Olga was destroyed were characterized by record values of the FWI, which caused a significant increase in the burned area and overwhelmed any response by the fire brigades.