Search

This report summarizes the modelling work that has been conducted for the Wildland-Urban Interface (WUI) during the CRBCPI-phase 1 project. The report first presents an overview of wildfires models and simulation tools. Then a detailed discussion is presented for the Fire Dynamic Simulator (FDS), the software used in the WUI simulations. FDS was used to build a model for simulating a WUI fire scenario and the simulation results are presented. Then kinetic modelling for single step reaction and multi –step reactions are thoroughly discussed. The procedures for finding the kinetic rate parameters from experimental data are shown with illustrative examples.

This report discusses the health impact of wildfires smoke on communities situated at the interface between wildland and urban areas, and the use of available air treatment technologies to mitigate this hazard. Wildfire smoke concerns are increasing with the increase of wildfires events frequency, which is partially attributed to climate change. Emissions from wildfires are chemically and physically complex and represent a high health hazard. Most of the health hazards from smoke are caused by the microscopic particles that can trigger heart attacks, breathing problems and other health issues. In response to wildfires events, communities are either asked to evacuate or seek a shelter-in-place. In order to protect the occupants from the smoke, high Indoor Air Quality (IAQ) should be provided within the shelter. The most commonly used technologies, for air treatment to improve the IAQ, are portable air cleaners and in-duct air filters. However, limited research is conducted to assess the efficiency of these technologies against wildfire smoke. Thus, this report suggests the development of a standard test for assessing air filters against wildfires smoke. Further, the report highly recommends developing guidelines for best practice at homes or community shelters to protect residents from wildfires induced smoke. The report is structured as follow, first types of shelter-in-place as alternative to population evacuation are presented followed by the discussion of the frequency of wildfires in Canada. Next a detailed discussion of emissions from these fires presented followed by discussing health effects of the exposure to wildfires smoke. Subsequently, current technologies for air treatment are discussed. Finally, international and provincial regulations and guidelines for reducing health risk of wildfires smoke are reported.

Models of wildland fire behaviour and spread as well as wildfire simulation tools have been reviewed and discussed; Fire behaviour models are categorized as Empirical, Semi-Empirical, Semi-physical or Physical models. Fire spread model generally falls under one of two categories; Raster based models or Vector based models. Spread models rely on fire behavior models as input. Wildfire software/tools are computer programs that incorporate behavior and spread models and provide relevant output such as GIS maps of fire spread versus time. Empirical and semi empirical behavior models are designed to model wildfire behavior in continuous and homogeneous wildland. Raster spread models and vector based models are also designed to model wildfire spread within the wildland. Physics based models are more suitable to model wildfire behavior and spread as related to wildland urbane interface since they rely on fundamental laws of physics which is applicable to both the wildland environment as well as the built environment., Interflam, 15th International conference and exhibition on Fire Science and Engineering, July 1-3, 2019, London, UK