4.4.3 Case Study #3: 2007 Southern California Fire Complex

 “What was unusual was the low moisture content of live fuels for this early date”. Keeley et al, 2009.

Igniting 4 years to the day after the October 2003 fire complex had started, the October 2007 sCA wildfires were born of near life-for-like fire-weather conditions [Fig. 38], the primary differentials being variance in the location and, in some instances the type of ignition source; 2007 the driest year on record, drought conditions were yet worse; and though wind-speeds were largely similar, at times the Santa Ana winds blew so strong as to render air-borne water dispersal ineffective, thus significantly diminishing fire crews’ capacity to fight the fires. As in 2003, the largest fires within the complex, the Witch and the Harris, burned in San Diego County.

While, at 972,147 acres [an area roughly 60% larger than Greater London], the fire complex’s burn scar was large (CALFIRE, 2007) [Figs. 39, 40], yet more acres were to burn in the immediate aftermath thereof, the total an estimated 1,000,000 (Keeley et al, 2009). Several of the fires spreading to areas that had burned just four years previously, notably in San Diego County where the Harris, Witch, and Poomacha fires relit over 74,132 acres (Ibid), whereas, in less severe fire-weather conditions, young vegetation [<5ys] would, in some terrains, have provided the ecological equivalent of a firebreak, saplings were largely incinerated (Ibid). Whereas, when fires swept through mature forest stands, such for example as occurred in Grass Valley, historic fire suppression had greatly increased the biomass abundance. Hence, as had occurred in October 2003, both fuel-state and quantity fuelled fires of greater intensity and severity than within the historic fire regime. Therein, humanity witnessed an event that occurred in consequence not of starving the hand that feeds, but the inverse thereof: as in 2003, the fire complex was, at least in part, a man-made monster - a ‘Frankenfire’.

Regionally, biomes including, but not limited to chaparral and mixed forests, are being subjected to stresses so severe, as for the probability of near-future [<2070] ecological regimes shifts [transition from one biome type unto another], not merely as relate to fire, but more generally, to be significant. Whereupon climatic, and in turn, fire conditions continue along the present trajectory, the future of many regional forests and shrublands will be precarious. Should these biomes transform into grasslands, the hydrological, geological, and ecological impact would be of such scale as would undermine landscape stability, thus increase the probability of landslides, mudslides, rockslides, greatly exasperate water-shortages, and degrade regional soils, thus undermining local agriculture. In the long run [2100>], should the state’s biomes largely transition to arid-lands, it would be not wildfire, but the absence thereof that would become a problem.

>Continue to Chapter 4 [part V] here.

The thesis is also available in PDF format, downloadable in several parts on Academia and Researchgate.

Note that figures have been removed from the digital version hosted on this site, but are included in the PDFs available at the links above.

Citation: Sterry, M. L., (2018) Panarchistic Architecture: Building Wildland-Urban Interface Resilience to Wildfire through Design Thinking, Practice and Building Codes Modelled on Ecological Systems Theory. PhD Thesis, Advanced Virtual and Technological Architecture Research [AVATAR] group, University of Greenwich, London.