California's Wildland Fires: 2000 vs. 2018

Using ArcGIS to create maps is a pretty simple process, especially with the abundance of reliable, open source data layers that are available. Using the Living Atlas in ArcMap, I added a Level IV ecoregion layer over a terrain basemap. I chose Level IV ecoregions because it is the most specific categorization. Please note that a map is only as good as its data, so be sure the layer sources are reliable and up-to-date. The layer I chose was created by the EPA and was last updated on May 15, 2019. I decreased the transparency so the topography was still slightly visible through the layer; it’s a significant factor for ecosystem characteristics and I wanted to see the correlation. The ecoregion layer was for all of the U.S., so I filtered this to only show those in California. I then combined this layer with my basemap. I knew I wanted to add more and did this to avoid having to fiddle with layering orders. 

My research taught me that 15 of California's 20 largest fires on record have occurred since 2000. I’ve also learned that fires are more expansive in recent years compared to historical records, with 2018 as the worst year to date. To observe this trend and correlate fire locations with their respective ecosystems, I added historical fire perimeter layers generated by the USGS in March 2019. Again, these layers were for the entire United States, so I filtered them to show only those in CA. I created two maps, the first for fires that occurred in 2000 and the other for 2018. 

The difference in fire size clear. While there were more fires in 2000, those in 2018 were much more extensive. Combined with the ecosystem layer, these also indicate which ecosystems are more prone to wildland fires and ultimately, where the greatest threats to biodiversity exist. These maps are interactive. Zoom in and click on different areas to view details for the specific ecoregions and fires.

2000:

2018:




Map layer sources:

Map service: US EPA Office of Environmental Information (OEI). Data: US EPA Office of Research and Development (ORD)

Wildland Fire Incidents Title: US Historic Fire Perimeters Online_Linkage: www.geomac.gov Online_Linkage

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