Development at the wildland–urban interface and the mitigation of forest-fire risk

doi:10.1073/pnas.0704488104

Development at the wildland–urban interface and the mitigation of forest-fire risk

^†Environmental Research and Teaching Institute,
^‡Physics Department, and
^¶Earth-Atmosphere-Ocean Department and Laboratoire de Météorologie Dynamique (Centre National de la Recherche Scientifique and Institut Pierre-Simon Laplace), Ecole Normale Supérieure, F-75231 Paris Cedex 05, France;
^§Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, UCB 450, Boulder, CO 80309; and
^‖Department of Atmospheric and Oceanic Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095

Communicated by Donald L. Turcotte, University of California, Davis, CA, May 19, 2007 (received for review April 19, 2006)

Abstract

This work addresses the impacts of development at the wildland–urban interface on forest fires that spread to human habitats. Catastrophic fires in the western United States and elsewhere make these impacts a matter of urgency for decision makers, scientists, and the general public. Using a simple fire-spread model, along with housing and vegetation data, we show that fire size probability distributions can be strongly modified by the density and flammability of houses. We highlight a sharp transition zone in the parameter space of vegetation flammability and house density. Many actual fire landscapes in the United States appear to have spreading properties close to this transition. Thus, the density and flammability of buildings should be taken into account when assessing fire risk at the wildland–urban interface. Moreover, our results highlight ways for regulation at this interface to help mitigate fire risk.

Footnotes

^††To who correspondence should be addressed at:
Environmental Research and Teaching Institute (CERES-ERTI), Ecole Normale Supérieure, 24, Rue Lhomond, F-75231 Paris Cedex 05, France.
E-mail: ghil{at}lmd.ens.fr
Author contributions: V.S., P.S.B., and M.G. contributed equally to this work; P.S.B. suggested the problem and provided data; M.G. designed research; V.S. performed research; V.S. analyzed data; and V.S., P.S.B., and M.G. wrote the paper.
The authors declare no conflict of interest.
Abbreviation:

WUI,

wildland–urban interface.
Freely available online through the PNAS open access option.