Modelling long-term fire regimes of southern California shrublands

Abstract

Abstract. This paper explores the environmental factors that drive the southern California chaparral fire regime. Specifically, we examined the response of three fire regime metrics (fire size distributions, fire return interval maps, cumulative total area burned) to variations in the number of ignitions, the spatial pattern of ignitions, the number of Santa Ana wind events, and live fuel moisture, using the HFire fire spread model. HFire is computationally efficient and capable of simulating the spatiotemporal progression of individual fires on a landscape and aggregating results for fully resolved individual fires over hundreds or thousands of years to predict long-term fire regimes. A quantitative understanding of the long-term drivers of a fire regime is of use in fire management and policy.

Brief Communication: Synoptic-scale differences between Sundowner and Santa Ana wind regimes in the Santa Ynez Mountains, California

“…Continuing work seeks to understand more precisely how Sundowner winds are produced and to provide more detailed information regarding their local variability across the Santa Ynez Mountains. This information could improve spot weather forecasts (Nauslar et al, 2016), evaluate future fire-weather-climate interactions (Peterson et al, 2011), and aid mitigating fire hazard in the Transverse Ranges.…”

Evaluating Spectral Indices for Assessing Fire Severity in Chaparral Ecosystems (Southern California) Using MODIS/ASTER (MASTER) Airborne Simulator Data

“…The standard ATCOR4 desert aerosol model was chosen. The visible through SWIR bands (1-25) were processed to surface reflectance, the MIR bands (26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40) were not atmospherically corrected and the thermal bands (41)(42)(43)(44)(45)(46)(47)(48)(49)(50) were atmospherically corrected to surface radiance. The surface radiance of the thermal bands was then separated into surface temperature (T s ) and surface emissivity ( ) using the emissivity normalization method [54].…”

“…The Landsat NBR is used as a post-fire management tool in the USA and Canada, e.g., as operationally used by the Burned Area Emergency Rehabilitation (BAER) teams in the conterminous USA [12]. Numerous studies have demonstrated the usefulness of the index in the North American boreal and temperate regions [11,31,[36][37][38], however, far fewer studies have assessed its effectiveness in California chaparral shrublands [9,20,39], an ecosystem which is highly sensitive to burning [39][40][41]. The few studies in the California chaparral shrublands demonstrated that the NBR is reasonably well related to fire severity, however, none of them conducted an inter-indices comparison.…”

Brief Communication: Differences between Sundowner and Santa Ana wind regimes in the Santa Ynez Mountains, California

“…Ongoing work seeks to evaluate meteorological conditions associated with historical large fire and warm season fire occurrence in the Santa Ynez to identify the frequencies of specific wind regimes associated with these fires. Further investigation using mechanistic fire models driven by fine scale (>5 km) weather inputs (e.g., Peterson et al 2011) will help clarify historical relationships and constrain the range of possible future shifts in fire frequencies under 25 varying scenarios of future land use change such as population growth, shifts in ecosystems in response to disturbance and climate, and climate itself. We postulate that for the Santa Ynez region, similar findings would occur for Sundowner events as Peterson et al (2011) found for SAW events, i.e., Sundowner intensity should also explain variance in modeled fire size and likely fire growth rate given broad similarity in fuels, terrain, and climate.…”