Chile Wildfires (Summer 2022)

Team: Chris Matechik (Project Lead), Reuben Alter, Jennifer Ruiz, Stephen Sene

Summary: In recent years, Central Chile has experienced wildfires of increasing frequency and intensity, which threaten natural resources and communities. The Corporación Nacional Forestal (CONAF) responds to wildfires caused by various ignitions, including lightning, but the prevalence of lightning-ignited wildfires is unknown. In collaboration with CONAF and the Embassy of Chile Agricultural Office, the team used Earth observations to map the coincidence of lightning strikes and wildfire ignitions. The Active Fire Product of Suomi NPP Visible Infrared Imaging Radiometer Suite (VIIRS) identified wildfires as thermal anomalies, which the team compared to the lightning events detected by NOAA’s GOES-16 Geostationary Lightning Mapper (GLM). Next, the team mapped lightning strike frequency and lightning-related wildfires across the study area. Finally, the team calculated and mapped a relative estimate of lightning-ignited wildfire vulnerability across the year, fire season (December – March), and off-season (April – November) by summing the following factors: lightning frequency, the Normalized Difference Moisture Index (NDMI) and land surface temperature (LST). These risks were then weighted by fuel availability. Preliminary analysis of the lightning-fire relationship showed a spatiotemporal coincidence, primarily in the South-central region of study, near Temuco, and isolated areas on the Andean front. The team identified areas at risk of lightning-induced wildfires, predominantly in the northern third of the study area and along the Andean front. Adjusting the relative weight of risk factors and improving the lightning and fire coincidence map by clustering VIIRS thermal anomalies into fire events could reduce discrepancies and improve risk assessments for future work.