The role of defensible space for residential structure protection during wildfiresAlexandra D. Syphard A D , Teresa J. Brennan B and Jon E. Keeley B C
A Conservation Biology Institute, 10423 Sierra Vista Avenue, La Mesa, CA 91941, USA.
B US Geological Survey Western Ecological Research Center, Three Rivers, CA 93271, USA.
C Department of Ecology & Evolutionary Biology, University of California, 612 Charles E. Young Drive, South Los Angeles, CA 90095-7246, USA.
D Corresponding author. Email: firstname.lastname@example.org
International Journal of Wildland Fire 23(8) 1165-1175 http://dx.doi.org/10.1071/WF13158
Submitted: 16 September 2013 Accepted: 30 May 2014 Published: 14 October 2014
With the potential for worsening fire conditions, discussion is escalating over how to best reduce effects on urban communities. A widely supported strategy is the creation of defensible space immediately surrounding homes and other structures. Although state and local governments publish specific guidelines and requirements, there is little empirical evidence to suggest how much vegetation modification is needed to provide significant benefits. We analysed the role of defensible space by mapping and measuring a suite of variables on modern pre-fire aerial photography for 1000 destroyed and 1000 surviving structures for all fires where homes burned from 2001 to 2010 in San Diego County, CA, USA. Structures were more likely to survive a fire with defensible space immediately adjacent to them. The most effective treatment distance varied between 5 and 20 m (16–58 ft) from the structure, but distances larger than 30 m (100 ft) did not provide additional protection, even for structures located on steep slopes. The most effective actions were reducing woody cover up to 40% immediately adjacent to structures and ensuring that vegetation does not overhang or touch the structure. Multiple-regression models showed landscape-scale factors, including low housing density and distances to major roads, were more important in explaining structure destruction. The best long-term solution will involve a suite of prevention measures that include defensible space as well as building design approach, community education and proactive land use planning that limits exposure to fire.
ReferencesAbsher JD, Vaske JJ (2011) The role of trust in residents’ fire wise actions. International Journal of Wildland Fire 20, 318–325.
| The role of trust in residents’ fire wise actions.CrossRef |
Agresti A (2007) ‘An Introduction to Categorical Data Analysis’, 2nd edn. (Wiley: New York)
Blanchi R, Lucas C, Leonard J, Finkele K (2010) Meteorological conditions and wildfire-related house loss in Australia. International Journal of Wildland Fire 19, 914–926.
| Meteorological conditions and wildfire-related house loss in Australia.CrossRef |
Boschetti L, Roy D, Barbosa P, Justice C (2008) A MODIS assessment of the summer 2007 extent burned in Greece. International Journal of Remote Sensing 29, 2433–2436.
| A MODIS assessment of the summer 2007 extent burned in Greece.CrossRef |
Burnham KP, Anderson DR (2002) ‘Model Selection and Multimodel Inference: a Practical Information-Theoretic Approach’, 2nd edn. (Springer-Verlag: New York)
Calfire (2000) ‘Wildland Fire Hazard Assessment Final Report on FEMA.’ (California Department of Forestry and Fire Protection: Sacramento, CA)
Calfire (2006) ‘General Guidelines for Creating Defensible Space.’ (California Department of Forestry and Fire Protection: Sacramento, CA)
Cary GJ, Flannigan MD, Keane RE, Bradstock RA, Davies ID, Lenihan JM, Li C, Logan KA, Parsons RA (2009) Relative importance of fuel management, ignition management and weather for area burned: evidence from five landscape–fire–succession models. International Journal of Wildland Fire 18, 147–156.
| Relative importance of fuel management, ignition management and weather for area burned: evidence from five landscape–fire–succession models.CrossRef |
Cedergreen N, Ritz C, Streibig JC (2005) Improved empirical models for describing hormesis Environmental Toxicology and Chemistry 24, 3166–3177.
| Improved empirical models for describing hormesisCrossRef | 1:CAS:528:DC%2BD2MXht12nu7fF&md5=0a75746abd8765200b35f60856af2f0bCAS | 16445100PubMed |
Chen K, McAneney J (2004) Quantifying bushfire penetration into urban areas in Australia. Geophysical Research Letters 31, L12212
| Quantifying bushfire penetration into urban areas in Australia.CrossRef |
Cheney P, Gould J, McCaw L (2001) The dead-man zone – a neglected area of firefighter safety. Australian Forestry 64, 45–50.
| The dead-man zone – a neglected area of firefighter safety.CrossRef |
Cohen JD (1999) Reducing the wildland fire threat to homes: where and how much? In ‘Proceedings of the Symposium on Fire Economics, Planning, and Policy: Bottom Lines’, 5–9 April 1999, San Diego, CA. (Eds A Gonzales-Caban, PN Omi) USDA Forest Service, Pacific Southwest Research Station, General Technical Report PSW-GTR-173, pp. 189–195. (Albany, CA)
Cohen JD (2000) Home ignitability in the wildland–urban interface. Journal of Forestry 98, 15–21.
Filmon G (2004) Firestorm 2003, provincial review. Report to the Provincial Government of British Columbia (Vancouver, BC) Available at http://bcwildfire.ca/History/ReportsandReviews/2003/FirestormReport.pdf [Verified 9 August 2014]
Foote EID, Gilless JK (1996) Structural survival. In ‘California's I-Zone.’ (Ed R Slaughter) pp. 112–121. (CFESTES: Sacramento, CA)
Foote EID, Martin RE, Gilless JK (1991) The defensible space factor study: a survey instrument for post-fire structure loss analysis. In ‘Proceedings of the 11th Conference on Fire and Forest Meteorology’, 16 April 1991, Bethesda, MD. (Eds PL Andrews, DF Potts) pp. 66–73. (Society of American Foresters: Bethesda, MD)
Franklin SE (1996) California’s catastrophic intermix fires causes, culprits and cures. American Fire Journal 48, 20–23.
Ganteaume A, Jappiot M, Corrine L (2013) Assessing the flammability of surface fuels beneath ornamental vegetation in wildland–urban interfaces in Provence (south-eastern France). International Journal of Wildland Fire 22, 333–342.
| Assessing the flammability of surface fuels beneath ornamental vegetation in wildland–urban interfaces in Provence (south-eastern France).CrossRef |
Gibbons P, van Bommel L, Gill MA, Cary GJ, Driscoll DA, Bradstock RA, Knight E, Moritz MA, Stephens SL, Lindenmayer DB (2012) Land management practices associated with house loss in wildfires. PLoS ONE 7, e29212
| Land management practices associated with house loss in wildfires.CrossRef | 1:CAS:528:DC%2BC38XhvVyktbY%3D&md5=21b333125eacd8fc5d5adada708cc716CAS | 22279530PubMed |
Gill AM, Stephens SL (2009) Scientific and social challenges for the management of fire-prone wildland–urban interfaces. Environmental Research Letters 4, 034014
| Scientific and social challenges for the management of fire-prone wildland–urban interfaces.CrossRef |
Gilmer M (1994) ‘California Wildfire Landscaping.’ (Taylor Publishing Company: Dallas, TX)
Gude PH, Rasker R, van den Noort J (2008) Potential for future development on fire-prone lands. Journal of Forestry 106, 198–205.
Haines TK, Renner CR, Reams MA (2008) A review of state and local regulation for wildfire mitigation. In ‘The Economics of Forest Disturbances: Wildfires, Storms, and Invasive Species’. (Eds TP Holmes, JP Prestemon, KL Abt) pp. 273–293. (US Forest Service: Washington, DC) Available at http://www.treesearch.fs.fed.us/pubs/32690 [Verified 9 August 2014]
Hammer RB, Radeloff VC, Fried JS, Stewart SI (2007) Wildland–urban interface housing growth during the 1990s in California, Oregon, and Washington. International Journal of Wildland Fire 16, 255–265.
| Wildland–urban interface housing growth during the 1990s in California, Oregon, and Washington.CrossRef |
Hessl AE (2011) Pathways for climate change effects on fire: models, data, and uncertainties Progress in Physical Geography 35, 393–407.
| Pathways for climate change effects on fire: models, data, and uncertaintiesCrossRef |
Howard RA, North DW, Offensend FL, Smart CN (1973) ‘Decision Analysis of Fire Protection Strategy for the Santa Monica Mountains: an Initial Assessment.’ (Stanford Research Institute: Menlo Park, CA)
Keeley JE, Baer-Keeley M, Fotheringham CJ (2005) Alien plant dynamics following fire in Mediterranean-climate California shrublands. Ecological Applications 15, 2109–2125.
| Alien plant dynamics following fire in Mediterranean-climate California shrublands.CrossRef |
Keeley JE, Safford HD, Fotheringham CJ, Franklin J, Moritz MA (2009) The 2007 southern California wildfires: lessons in complexity. Journal of Forestry 107, 287–296.
Keeley JE, Syphard AD, Fotheringham CJ (2013) The 2003 and 2007 wildfires in southern California. In ‘Natural Disasters and Adaptation to Climate Change’. (Eds S Boulter, J Palutikof, DJ Karoly, D Guitart) pp. 42–52. (Cambridge University Press: Oxford, UK)
King G, Zeng L (2001) Logistic regression in rare events data. Political Analysis 9, 137–163.
| Logistic regression in rare events data.CrossRef |
Knezevic SZ, Streibig JC, Ritz C (2007) Utilizing R software package for dose-response studies: the concept and data analysis. Weed Technology 21, 840–848.
| Utilizing R software package for dose-response studies: the concept and data analysis.CrossRef |
Kursar TA, Engelbrecht BMJ, Burke A, Tyree MT, El Omari B, Giraldo JP (2009) Tolerance to low leaf water status of tropical tree seedlings is related to drought performance and distribution. Functional Ecology 23, 93–102.
| Tolerance to low leaf water status of tropical tree seedlings is related to drought performance and distribution.CrossRef |
Leonard J, Blanchi R, Lipkin F, Newnham G, Siggins A, Opie K, Culvenor D, Cechet B, Corby N, Thomas C, Habili N, Jakab M, Coghlan R, Lorenzin G, Campbell D, Barwick M (2009) Building and land-use planning research after the 7th February Victorian bushfires: preliminary findings. CSIRO and Bushfire CRC. (Melbourne)
Maire RG (1979) ‘Landscape for Fire Protection.’ (University of California Agriculture Extension Service: Los Angeles, CA)
Maranghides A, Mell WE (2009) A case study of a community affected by the Witch and Guejito fires. NIST Technical Note 1635. (Washington, DC)
Quarles SL, Valachovic Y, Nakamura GM, Nader GA, DeLasaux J (2010) Home survival in wildfire-prone areas: building materials and design considerations. University of California, Agriculture and Natural Resources, ANR Publication 8393. (Richmond, CA) Available at http://anrcatalog.ucdavis.edu/pdf/8393.pdf [Verified 9 August 2014]
R Development Core Team (2012) R: a language and environment for statistical computing. (R Foundation for Statistical Computing, Vienna, Austria) Available at http://www.R-project.org/ [Verified 23 August 2013]
Ramsey GC, McArthur NA (1994) Planning in fire-prone areas: building survival. In ‘Bushfire! Looking to the Future: Papers from the Nature Conservation Council of NSW Seminar’, June 1994. (Eds C Brown, L Tohver) pp. 142–150. (Envirobook: Sydney)
Ritz C, Streibig JC (2013) Package ‘drc’ analysis of dose-response curves. Available at http://cran.r-project.org/web/packages/drc/index.html [Verified 9 August 2014]
Schoennagel T, Nelson CR, Theobald DM, Carnwath GC, Chapman TB (2009) Implementation of National Fire Plan treatments near the wildland–urban interface in the western United States. Proceedings of the National Academy of Sciences of the United States of America 106, 10 706–10 711.
| Implementation of National Fire Plan treatments near the wildland–urban interface in the western United States.CrossRef | 1:CAS:528:DC%2BD1MXos1ajsbc%3D&md5=ec05f847339df19743686fb283c3e3d9CAS |
Sheskin DJ (2004) ‘Handbook of Parametric and Nonparametric Statistical Procedures’, 3rd edn. (Chapman & Hall and CRC: Boca Raton, FL).
Smith E, Adams G (1991) ‘Incline Village/Crystal Bay Defensible Space Handbook.’ (University of Nevada: Reno, NV)
Spittler TE (1995) Fire and the debris flow potential of winter storms. In ‘Brushfires in California Wildlands: Ecology and Resource Management.’ (Eds JE Keeley, T Scott) pp. 113–120. (International Association of Wildland Fire: Fairfield, WA)
Stockmann K, Burchfield J, Calkin D, Venn T (2010) Guiding preventative wildland fire mitigation policy and decisions with an economic modeling system. Forest Policy and Economics 12, 147–154.
| Guiding preventative wildland fire mitigation policy and decisions with an economic modeling system.CrossRef |
Streibig JC, Rudemo M, Jensen JE (1993) Dose-response curves and statistical models. In ‘Herbicide Bioassays.’ (Eds JC Streibig, P Kudsk) pp. 29–55. (CRC: Boca Raton, FL)
Syphard AD, Franklin J, Keeley JE (2006) Simulating the effects of frequent fire on southern California coastal shrublands. Ecological Applications 16, 1744–1756.
| Simulating the effects of frequent fire on southern California coastal shrublands.CrossRef | 17069368PubMed |
Syphard AD, Radeloff VC, Keuler NS, Taylor RS, Hawbaker TJ, Stewart SI, Clayton MK (2008) Predicting spatial patterns of fire on a southern California landscape. International Journal of Wildland Fire 17, 602–613.
| Predicting spatial patterns of fire on a southern California landscape.CrossRef |
Syphard AD, Keeley JE, Massada AB, Brennan TJ, Radeloff VC (2012) Housing arrangement and location determine the likelihood of housing loss due to wildfire. PLoS ONE 7, e33954
| Housing arrangement and location determine the likelihood of housing loss due to wildfire.CrossRef | 1:CAS:528:DC%2BC38XltlOit7w%3D&md5=b5f8814d69a6a42c3a290c5f9aed9317CAS | 22470499PubMed |
Syphard AD, Bar Massada A, Butsic V, Keeley JE (2013) Land use planning and wildfire: development policies influence future probability of housing loss. PLoS ONE 8, e71708
| Land use planning and wildfire: development policies influence future probability of housing loss.CrossRef | 1:CAS:528:DC%2BC3sXhtleru7fI&md5=f522d894fa30694f7ab3d58dc41e63edCAS | 23977120PubMed |
Vasquez T (2011) The Russian inferno of 2010. Weatherwise 64, 20–25.
| The Russian inferno of 2010.CrossRef |
Venables WM, Ripley BD (1994) ‘Modern Applied Statistics with S-Plus.’ (Springer-Verlag: New York)
Wilson AAG, Ferguson IS (1986) Predicting the probability of house survival during bushfires. Journal of Environmental Management 3, 259–270.
Winter G, McCaffrey S, Vogt CA (2009) The role of community policies in defensible space compliance. Forest Policy and Economics 11, 570–578.
| The role of community policies in defensible space compliance.CrossRef |
Witter M, Taylor RS (2005) Preserving the future: a case study in fire management and conservation from the Santa Monica Mountains. In ‘Fire, Chaparral, and Survival in Southern California’. (Ed. RW Halsey) pp. 109–115. (Sunbelt Publications: San Diego, CA)
Zárate L, Arnaldos J, Casal J (2008) Establishing safety distances for wildland fires. Fire Safety Journal 43, 565–575.
| Establishing safety distances for wildland fires.CrossRef |