Playing with Fire (Data) 3

I’ve been digging further into the fire data from my last post (here and here), trying to see if there is a pattern that might explain the large number of Riverside County fires in 2007.

Here are some descriptive numbers.  Of the 955 fires in Riverside County during 2007:

932 (97.6%) of were unnamed.  The vast majority of fires in the data set have names.  But many of these riverside fires do not.  This is unusual.  Only four Riverside fires in other years were unnamed.   However, 2007 had the largest number of unnamed fires across the state (2529/3211, 78.8%)

933 (97.7%) burned 1 acre or less.  The average percentage of such fires for Riverside across all other years was 67.5%.  Statewide, 2007 had a relatively high percentage of fires that burned 1 acre or less (88.6%, 84.8% without Riverside), but not the highest (1976: 89.6%).  Note that most (92.5%), but not not all of these fires were unnamed.

A total of 2721 acres was burned.  For all other years, the average total acreage burned in Riverside was 14,902 acres.  Across the state, a total of 648,614 acres were burned in 2007. This was the largest annual total in the data set.

By comparison, San Diego County had the largest total area burned in 2007 with 453,447 acres burned by 172 fires.  Santa Clara County had the largest average fire size, with 10 fires averaging 9,552 acres each.

This chart shows how much of an outlier the number of fires in Riverside is.  The next highest fire count was for San Diego County in 1998 (424 fires).

In terms of total acreage burned in Riverside County, 2007 was comparatively small.  This chart pulls the Riverside County data from the statewide chart above.  Note the overall increase in fire count between 1998 and 2006.

The majority of the 2007 fires took place in western Riverside County, many in what seem to be residential areas.  Marker size on the maps below indicates the acreage burned.


My best guess for a reason behind the increased fire count is that it represents an increase in the number of residential fire reports submitted to WFMI.  Of course, that is just a guess and I have no additional information to back it up.  Internet searches do not show an increase in arson incidents or any news items that might offer an explanation.  Maybe someone out there has a better idea.  If so, let me know.  All I can say is that I’ve enjoyed digging into the data and figuring out how to generate some new types of displays.


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