In order to create my fire hazard model for the Station Fire region, I retrieved data from various sources including, a digital elevation model, landcover data, and the perimeter of the station fire. First I analyzed the slope using the DEM and the spatial analyst tool. Next I reclassified the slope percentage grid in order to represent the corresponding NFPA Hazard Points for each slope range. Therefore, the areas with flat slopes have low hazard points, while the areas with steep slopes have higher hazard points. Slope is an important factor in predicting wildfires because a steeper slope has a greater risk of catching fire. However, land cover is a more important factor than slope when determining the fire risk of a region.
The second component of my fire hazard model was analyzing the land cover near the station fire perimeter. First I reclassified the FBO Fuel Codes in order to represent the corresponding NFPA Hazard Points for each group of land cover types. The five classes of fuel types were Non-Fuel (0), Light (5), Medium (10), Heavy (20), and Slash (25). The area within the Station Fire perimeter is dominated with land cover with high NFPA Hazard Points, implying that this area has a high fire risk.
The final component of this fire hazard model is a map of combined factors. In order to merge these two data sets, I used the raster calculator to add the slope and land cover data values. The final product shows the areas at greatest risk (highest NFPA Hazard Points) in red, orange, and yellow, while showing the areas with the least risk (lowest NFPA Hazard Points) in green and blue. After viewing the final map, it is apparent that the region within the Station Fire perimeter has a huge risk of being destroyed by wildfires due to its flammable vegetation and steep slopes.
The greatest challenge that I encountered when creating this model was the reclassification of the slope and land cover data. It was difficult to make decisions about how many classes to make and what ranges within those classes. Also when I encountered data with a different projection, I had to do some investigating in order to determine what projection and datum to convert the map to.
Citations:
"Digital Elevation Model of Los Angeles." Seamless Data Warehouse. USGS. <http://seamless.usgs.gov>.
"Station Fire Perimeters – GIS shapefiles." Los Angeles County Enterprise GIS. <http://egis3.lacounty.gov/eGIS/?p=1035>.
"Surface Fuels Data Files." Fire and Resources Assessment Program (FRAP). California Department of Forestry and Fire Protection. <http://frap.cdf.ca.gov/data/frapgisdata/download.asp?spatialdist=2&rec=fmod>.
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