October 10, 2017 —CNN
At least 10 people are dead and more than 20,000 have been evacuated as wildfires burn in California’s wine country and other parts of the state.
More than 100 people have been hospitalized for fire-related injuries or health issues, including burns, smoke inhalation and shortness of breath. An estimated 1,500 structures have been destroyed and at least 57,000 acres are affected.
California’s governor has declared a state of emergency for three counties. Authorities have not said what caused the fires but noted that dry conditions made it easy for the fires to spread.
On the night of November 28, 2016 residents of Gatlinburg, Tennessee, found themselves in the midst of a firestorm. Within hours, a small blaze consumed homes, businesses and lives.—the worst fire in the Smoky Mountains in a hundred years, forcing thousands to flee and leaving fourteen dead.
Dr. Nigel Kaye has been researching how wildfire spreads and has received a grant to measure exposure risk for homes in WUI (wildland-urban interface) communities.
Home ignition due to ember a
ccumulation on a building is a significant risk in WUI fires. Mid-scale boundary layer wind tunnel experiments will be run to examine the influence of wind speed, ember geometry, ember loading (embers per square meter per second), building layout, home plan density (homes per acre), and building shape on ember accumulation on and around buildings. Matching the ember number will ensure the experiments are dynamically similar to full-scale WUI fires.
The experimental program will also increase both our quantitative and qualitative understanding of ember transport through WUI communities and will enable the development of risk reduction heuristics to increase WUI community disaster resilience. Identification of community features or fire and wind conditions that consistently result in the capture of large numbers of embers on houses will enable developers to design more fire-resilient communities. Such information will also enable emergency responders to better focus resources and establish appropriate evacuation plans.
The development of an experimental technique for quantifying ember accumulation in a WUI community could be used as part of a community design process. A wind tunnel study of a particular design could highlight potential ember accumulation risks that could be mitigated during an iterative design process. This type of study is routine for establishing the risk of high pedestrian level winds in urban developments and could prove an invaluable tool for fire-resilient WUI community development.
