Wildfire Risk Assessment: Western Travis County, Texas

Integrating GIS and Fire Modeling

Jennifer Perry CE 394K GIS

Spatially and temporally simulate the spread and behavior of fires.

GIS based data input

Simulate weather, fuels, heterogeneous terrain

Simulate attack scenarios

Fire Simulator

Digital Elevation Model

Slope

Aspect

Fuels

Canopy Density

Required GIS Raster Files

.LCP file

Digital Elevation Models

Required GIS Raster Files

Downloaded from TNRIS – Digital Data site

USGS Mansfield Dam Quadrangle 30 meter resolution

UTM – NAD 27 projection

Slope

Required GIS Raster Files

Derived from DEM using ArcView Spatial Analyst

USGS Mansfield Dam Quadrangle 30 meter resolution

UTM – NAD 27 projection

Aspect

Required GIS Raster Files

Derived from DEM using ArcView Spatial Analyst

USGS Mansfield Dam Quadrangle 30 meter resolution

UTM – NAD 27 projection

Fuels

Required GIS Raster Files

Fuels

Required GIS Raster Files

USGS LULC vector file in digital degrees

Clipped against Mansfield Dam quad

Projected into UTM – NAD 27

Converted to grid based on DEM

Canopy Cover

Required GIS Raster Files

Interpolated from LULC grid

Expressed as percent density

Projected into UTM – NAD 27

Converted to grid based on DEM

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

Field Site

Extent of Fire

Lake Travis

FARSITE Simulation

Chagoopa.LCP

Ignition conditions:Elevation = 2208 mSlope = 290

Aspect = 1350

Fuel = 7 Southern Rough Chaparral (2-6 ft)Canopy Cover = 1

500 m

Closed Timber Litter ExposedRock

SouthernRough

Chaparral

Short grass 1ft

FARSITE Simulation

Fire characteristics:

Duration: 1 day

T = 800 F, no wind

Time step: 30 minutes

Visible time step: 2 hours500 m

What’s Left?

Compile Mansfield Dam raster files into .LCP file

Use FARSITE to convert Fuel Model from standardAnderson criteria to Fire Behavior Fuel Model

Run simulation based on Labor Day Fire

Overlay roads.shp and hydrants.shp to determineeffectiveness of attack

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