A Wildfire Monitoring Method Based on Daily Nighttime Light Data: A Case Study of the Los Angeles Wildfire

Wildfires are among the most destructive natural disasters, inflicting severe and irreversible damage to ecosystems and human societies. However, most existing research lacked sufficient spatial coverage and spatiotemporal continuity to provide near-real-time assessments of wildfire impacts, including their extent and severity. Leveraging globally accessible, temporally continuous nighttime light (NTL) data from National Aeronautics and Space Administration (NASA)’s Black Marble VNP46A1 product, this study developed a threshold-based method to delineate wildfire-affected areas and quantify impact severity from daily observations, providing a rapid and scalable solution for near-real-time wildfire assessment across diverse regions and events. The method was applied to the Los Angeles (LAs) wildfire of January 2025, which resulted in infrastructure losses exceeding U.S. $50 billion. The results showed that the proposed approach effectively captured wildfire-affected regions—particularly in the Palisades, Eaton, and Hurst areas—covering approximately 307.75 km². The sharp increase in NTL intensity from ∼30 to 4750 nW/cm²/sr revealed the extreme burning severity of the event. Furthermore, approximately 30 252 buildings and 281 240 individuals were estimated to be directly affected, with impacts classified into five severity levels to characterize variations in damage intensity across the affected areas. Overall, the proposed method demonstrated strong potential for large-scale wildfire monitoring and rapid impact assessment, offering near–real-time applicability and globally accessible data support.