Date of Award

5-2007

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Ocean Engineering and Marine Sciences

First Advisor

Sen Chiao

Second Advisor

George A. Maul

Third Advisor

Judith A. Barlow

Abstract

“Fire weather” addresses fire behavior in specified fuels under various weather conditions. In a wildland context, the term “fuel” describes any organic matter, live or dead, that will ignite and bum in a fire. Fuels vary in species, location, and abundance, and may lie in a substrate, surface layer, and/or canopy. Fuel moisture varies to maintain equilibrium with the atmosphere. Fire propagation is the progressive movement of fire in space and time. Advancements of fire from one discrete fuel element to the next is a process that involves heat production, heat transfer, and heat absorption, and is dependent on fuel type and the environment. Wildfires cause serious damage to natural wildlife, property, and humans. Minimizing this threat lies in the hands of fire managers, who need the ability to assess fire potential across their areas. It is, therefore, important to ensure that fuels are incorporated into models to forecast wildfires realistically. The Fire Area Simulator (FARSITE) is a two-dimensional deterministic model for spatial and temporal fire growth. FARSITE calls for the support of a Geographic Information System (GIS), such as ArcView or GRASS, to generate and provide five raster data themes containing fuels, elevation, slope, aspect, and canopy cover, in ASCII file format. Weather information is also needed from the RAWS network. Once file directories are made a landscape can be created using the theme files. Parameters are set for time steps and distance and the simulation time is acquired. Once the location of the fire ignition is placed the simulation can be run. Simulation output is in tabular, vector, graphical, and raster formats. The FARSITE model was created to offer support in the planning and operation of fires to fire managers who execute prescribed natural fires (PNFs). In this study, the 2006 Central Florida wildfire events are under investigation using FARSITE, which simulates fire spread and behavior under conditions of an assorted terrain using information on fuel type and moisture, elevation, slope, aspect, canopy cover, and weather. Data related to wildfires has been collected for the Orlando District, which is Orange, Brevard, Osceola, and Seminole counties, from the Florida Division of Forestry. The main goals of this research are to implement and configure the FARSITE model and conduct case studies to further validate the model using the Areca Palm fire. For this study the validation will be confined to comparing observations of wildfires in Central Florida to those fields that are calculated by the model. Comparisons will be conducted for a range of atmospheric conditions and fuel variations. Model output for the Areca Palm fire nearly matched actual fire movement. Changes were made to fuel moisture content and different weather variables, and properly showed how the fire would move if the fuel was dry, as well as if there was no wind and increased rainfall and cloud cover. The results provide a benchmark of the consistency of the fuel parameterization in the FARSITE model within different weather regimes. Having financial support is substantial in fighting wildfires. Governments budget hundreds of thousands of dollars for prescribed bums and wildfire emergencies. In 2003 prescribed bums cost $5 to $70 an acre, while wildfires cost $500 to $1,600 an acre to battle. Using these numbers, the fires shown in the FARSITE program would cost millions of dollars to fight. Technological advances can prevent out of control fires, as well as using certain models, such as the Haines Index and the Keetch-Byram Index, in fire weather forecasts. Proper education to the community can also assist in preventing wildfire emergencies.

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