Southern CA Fires and Other Hazards

Because I’m from Pasadena, I’ve been keeping a close eye on what’s been going on with the Station fire. This is the one that’s been burning in the San Gabriel Mountains north of the LA basin for the past week or so. Because the fire is threatening a lot of places I know pretty well, I’ve found it frustrating to look at some of the more generalized fire maps. Shaded relief with a polygon of the burn area just doesn’t do it for me. Fortunately, the GeoMAC (Geospatial Multi-Agency) Fire Team puts out twice-daily updates of the fire perimeters as Google Earth KML files.  Here is the southeastern edge of the Station fire, updated this evening. (I modified the map symbols so that the burn area is filled red.)

Google Earth imagery with Station fire burn area as of 9/1/09 (red). Station Fire perimeter from GeoMAC Fire Team.

Google Earth imagery with Station fire burn area as of 9/1/09 (red). Station Fire perimeter from GeoMAC Fire Team.

Unfortunately, I could tell from the map that one of my favorite places to go hiking as a kid, Millard Canyon, has burned. Two firefighters died higher up in the San Gabriels, near Mt. Gleason. Some homes  have burned near Mt. Wilson (E of this view) and in the Sunland/Tujunga area (NW of here). So far, though, the damage in the area pictured here has been less than people had feared. The news reports were talking a lot about the La Vina development in Altadena. La Vina wasn’t a name familiar to me, even though the development shows up in the Google Earth image – it’s near the left side, just above the words “West Ravine.” It turns out it’s just one canyon over from where I went to summer camp. Looking at Google Earth’s historical imagery revealed why I’d never heard of La Vina: it wasn’t around when I lived there.

Google Earth historical imagery (May 1994) with Station fire burn area as of 9/1/09 (red). Station Fire perimeter from GeoMAC Fire Team.

Google Earth historical imagery (May 1994) with Station fire burn area as of 9/1/09 (red). Station Fire perimeter from GeoMAC Fire Team.

This kind of development at the urban-wildland interface brings up all kinds of issues I like to talk about when I teach geohazards: What factors determine fire risk? What are the tradeoffs we make when choosing whether to suppress fires? What are the socioeconomic issues that come up when people decide to build at the urban-wildland interface? Should we be developing there at all?

The socioeconomic issue is one that students often overlook. Many of these houses are very expensive (think about the view!), and the residents of LA county pay good money to protect them: how much does it cost to rent a 747 full of flame retardant? Census data put the upper quartile home value in this block group as ~$300-500K, so – thinking cynically – there’s a lot of tax base to protect. You real geographers out there can ding me on which stat and aggregation I used (I got the data from Stanford’s GCensus project)… I’m not sure my interpretation is right, though I’m fairly sure I can’t afford a house in La Vina (Zillow shows prices way out of the range of an assistant professor’s salary). And I really don’t think so cynically: I have at least one friend who lives near there, and I’m very glad they’re safe.

Google Earth image (October 2007) with Station Fire perimeter and census block groups colored by upper quartile home value. The block group with the La Vina development is in the $286,700-$504,300 category.

Google Earth image (October 2007) with Station Fire perimeter and census block groups colored by upper quartile home value.

These issues are all covered, though not from a fire point of view, in John McPhee’s essay “Los Angeles versus the Mountains” in The Control of Nature, which I have students read. Not coincidentally, the geographic setting of McPhee’s essay is not far away (just a few miles E) from the location of this image. I urge you to check out the construction from 1994-2007 in the Pasadena Glen area, where McPhee did some of his interviews.

Anyway, don’t let any of this discussion minimize the human side of fire damage. People are putting their lives on the line down there. I meant this post to show how a personal concern might lead to awareness of some larger issues. I guess that when I teach a class like geohazards, my goal is to give students to tools to make the same discovery – though I never really thought about it until I did it myself.

Thanks to Samantha Weber for the link to the GeoMAC page!