Wildfires are an important disturbance factor within chaparral ecosystems of southern California’s Mediterranean-type climate zones, as well as a hazard to the hundreds of thousands of people who reside in the wildland-urban interfaces of this region. Our research examines the role of chaparral shrubland vegetation as a fuel type on wildfire spread and danger, as well as the rate and distribution of vegetation regrowth following fires. A major emphasis of this research is the exploitation of optical remote sensing imagery captured from airborne and satellite sensors at spatial resolutions between 0.1 m and 1 km to map, monitor and study chaparral fuel loadings, regrowth, and fire spread.
Wildfire Fuel and Spread Relationships for Chaparral Shrublands of Southern California
This project is funded by National Science Foundation Geography and Spatial Sciences. We are developing and applying novel methods to answer fundamental questions about wildfire growth -- Through what mechanisms do fires spread? and How fast? -- with an emphasis on southern Californian chaparral, an important fire ecosystem in which fire behavior is poorly understood. We capture and analyze repetitive airborne thermal infrared (ATIR) imagery to illuminate and identify the mechanisms through which fires spread, and to produce some of the first measurements of fire spread rates (FSR) along wildfire fronts burning in a natural landscape. We apply spatial analysis and landscape ecological techniques for unraveling the separate effects of fuels, terrain, and wind speed (another variable to be extracted from the ATIR data), which are the environmental factors that determine spread rate of wildfires. To address this secondary objective, we will generate metrics from pre-fire high spatial resolution imagery to indicate the amount, type and spatial arrangement of vegetation. Because the approach is empirical and the study covers a finite time period, the specific location and nature of wildfires that occur within the western US will set the analytical domain, with an emphasis on southern California.
Postfire Recovery of Chaparral Shrublands
Multiple funded projects, theses, and dissertations have been conducted on this topic, with past funding from US Forest Service and current funding from NASA (Earth and Space Science Fellowship). Our multi-scale remote sensing analyses have been supported by extensive field observations and measurements, particularly for coastal sage scrub and chaparral communities. An emphasis of the research is the influences of frequent short interval fires and drought on the nature of postfire recovery of these shrublands.