Fire risk to structures in California's Wildland-Urban Interface.

Journal: Nature communications
Published Date:

Abstract

The destructive impacts of wildfires on people, property and the environment have dramatically increased, especially in the Wildland-Urban Interface (WUI) in California. In these areas structures are threatened by both approaching flames and lofted embers which spread fire into and within communities. While independent factors influencing structure fire protection are well known, their combined effects remain largely unquantified, limiting the accuracy of risk assessments and mitigation strategies. Here, we examine five major historical WUI fires-2017 Tubbs, 2017 Thomas, 2018 Camp, 2019 Kincade, and 2020 Glass Fires-utilizing machine learning (ML) analysis of on-the-ground post-fire data collection, remotely sensed data, and fire reconstruction modeling to assess patterns of structure loss and mitigation effectiveness. We show that the spacing between structures is a critical factor influencing fire risk, highlighting the importance of structure arrangement, while fire exposure, the ignition resistance (hardening) of structures, and clearing around structures (defensible space) work in combination to mediate fire risk. Utilizing an XGBoost classifier, structure survivability can be predicted to 82% accuracy. Results highlight the effectiveness of hardening and defensible space, with a hypothetical 52% reduction in losses. Our findings emphasize the need for community-level mitigation to reduce structure loss in future WUI fires.

Authors

  • Maryam Zamanialaei
    Department of Mechanical Engineering, University of California, Berkeley, CA, USA.
  • Daniel San Martin
    Departamento de Informática, Universidad Técnica Federico Santa María, Valparaíso, Chile.
  • Maria Theodori
    Department of Mechanical Engineering, University of California, Berkeley, CA, USA.
  • Dwi Marhaendro Jati Purnomo
    Department of Mechanical Engineering, University of California, Berkeley, CA, USA.
  • Ali Tohidi
    Department of Fire Protection Engineering, University of Maryland, College Park, MD, USA.
  • Chris Lautenberger
    CloudFire Inc., Auburn, CA, USA.
  • Yiren Qin
    Department of Fire Protection Engineering, University of Maryland, College Park, MD, USA.
  • Arnaud Trouvé
    Department of Fire Protection Engineering, University of Maryland, College Park, MD, USA.
  • Michael Gollner
    Department of Mechanical Engineering, University of California, Berkeley, CA, USA. mgollner@berkeley.edu.