Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Knowing exposure risks important to saving structures from wildfires

A recent study of one of California's most devastating wildland fires by the National Institute of Standards and Technology (NIST) and the U.S. Forest Service (USFS) strongly suggests that measures for reducing structural damage and property loss from wildland urban interface (WUI)* fires are most effective when they are based on accurate assessments of exposure risks both for individual structures and the community as a whole.

The report also describes how the NIST-USFS WUI Hazard Scale provides a state-of-the-art tool for making such assessments and how that data could be linked to improved building codes, standards and practices that will help communities better resist the threat of wildfires.

The Witch Creek/Guejito WUI fire (commonly known as the Witch Fire) was the largest of a series of wildfires that began burning across Southern California on Oct. 20, 2007. It affected areas north and northeast of San Diego, starting in Witch Creek Canyon near Santa Ysabel and quickly spreading westward toward the coast because of strong Santa Ana winds. The Witch Fire burned some 80,000 hectares (nearly 200,000 acres), destroyed more than 1,600 structures, caused an estimated $1.8 billion in property damages and cost $18 million to fight. It also was responsible for two civilian deaths and 39 firefighter injuries.

A NIST-USFS WUI team worked in collaboration with the California Department of Forestry and Fire Protection (CAL FIRE) and the City of San Diego to collect post-incident data within the Witch Fire perimeter. The team focused its effort on The Trails development at Rancho Bernardo, north of San Diego. There were 274 homes in The Trails, with 245 within the fire perimeter. Seventy-four homes were completely destroyed and 16 were partly damaged. Field measurements made by the NIST team included structure particulars, specifically roof type; proximity of combustibles to the structure; and damage to wildland and residential vegetation. Documentation included more than 11,000 photographs.

The data collected and analyzed were used in two separate NIST-USFS reports. The first, issued in 2009, created a detailed timeline of the Witch Fire, tracked its impact on the community, and documented defensive actions taken by homeowners and first responders. The latest study evaluates the effectiveness of those mitigation techniques addressing exposure risks—as defined by the WUI Hazard Scale—associated with direct fire contact and ignition by embers.

"This is the first time anyone has looked at wildfire impact by evaluating pre-event exposure risks throughout an entire community and how those risks affected the defensive actions that were in place," says Alexander Maranghides, lead author of both Witch Fire reports.

What the researchers found was that the majority of defensive strategies used in The Trails were effective and that the level of effectiveness was correlated to fire and ember exposure. Damage and destruction were more prevalent in structures assessed by the WUI Hazard Scale as having been at highest risk from fire and embers. Accordingly, defensive actions were more than twice as effective in saving structures in low-exposure sections of the community as compared to high-risk areas.

Maranghides says that a pre-event knowledge of exposure risks also may be helpful in determining how firefighters attack a WUI fire. "Our data show that it's probably best to fight fires in low-exposure areas because there's a greater chance that they can be suppressed and with less danger to the crews," he explains. "It may be better to sacrifice structures in high-exposure areas than risk the loss of firefighter lives in unwinnable situations."

Useful links:

1) The newest study: A. Maranghides, D. McNamara, W. Mell, J. Trook and B. Toman. A Case Study of a Community Affected by the Witch and Guejito Fires: Report #2 – Evaluating the Effects of Hazard Mitigation Actions on Structure Ignitions. NIST Technical Note 1796 (2013) at

2) Announcement of the NIST/USFS WUI Hazard Scale: "NIST, Forest Service Propose System to Help Communities Resist Wildfires," NIST Tech Beat, Dec. 12, 2012.

3) First NIST study of the Witch fire: "NIST Study Offers First Detailed Look at the Progress of a Wildland-Urban Fire," NIST Tech Beat, June 16, 2009.

* USFS defines the wildland urban interface, or WUI, as an "area where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels."

Michael E. Newman | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>