Wildfire Risk Assessment: Western Travis County, Texas

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Wildfire Risk Assessment Western Travis County,
Texas

• Integrating GIS and Fire Modeling
• Jennifer Perry CE 394K GIS

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Fire Simulator

• Spatially and temporally simulate
• the spread and behavior of fires.
• GIS based data input
• Simulate weather, fuels,
• heterogeneous terrain
• Simulate attack scenarios

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Required GIS Raster Files

• Digital Elevation Model
• Slope
• Aspect
• Fuels
• Canopy Density

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Required GIS Raster Files

• Digital Elevation Models

• Downloaded from TNRIS
• Digital Data site
• USGS Mansfield Dam Quadrangle
• 30 meter resolution
• UTM NAD 27 projection

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Required GIS Raster Files

• Slope

• Derived from DEM using
• ArcView Spatial Analyst
• USGS Mansfield Dam Quadrangle
• 30 meter resolution
• UTM NAD 27 projection

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Required GIS Raster Files

• Aspect

• Derived from DEM using
• ArcView Spatial Analyst
• USGS Mansfield Dam Quadrangle
• 30 meter resolution
• UTM NAD 27 projection

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Required GIS Raster Files

• Fuels

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Required GIS Raster Files

• Fuels

• USGS LULC vector file in
• digital degrees
• Clipped against Mansfield Dam quad
• Projected into UTM NAD 27
• Converted to grid based on DEM

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Required GIS Raster Files

• Canopy Cover

• Interpolated from LULC grid
• Expressed as percent density
• Projected into UTM NAD 27
• Converted to grid based on DEM

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Field Site

• 5-6 acre brush fire
• September 4, 2000
• Record high of 1100 F

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Extent of Fire
Lake Travis
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FARSITE Simulation
Ignition conditions Elevation 2208 m Slope
290 Aspect 1350 Fuel 7 Southern Rough
Chaparral (2-6 ft) Canopy Cover 1
500 m
Chagoopa.LCP
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FARSITE Simulation

• Fire characteristics
• Duration 1 day
• T 800 F, no wind
• Time step 30 minutes
• Visible time step 2 hours

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Whats Left?

• Compile Mansfield Dam raster files into .LCP
  file
• Use FARSITE to convert Fuel Model from standard
• Anderson criteria to Fire Behavior Fuel Model
• Run simulation based on Labor Day Fire
• Overlay roads.shp and hydrants.shp to determine
• effectiveness of attack

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Thanks to Brian Quinlan, Hudson Bend Fire
Department, for access to GIS files