International Journal of Wildland Fire
Volume 22
Number 7 2013
This paper presents estimates of potential future wildfire suppression cost savings that result from allowing a current wildfire to burn on a landscape in central Oregon. Under some conditions, estimated savings were large, suggesting that the benefit of allowing a wildfire to burn may, in select cases, outweigh the additional risk of loss.
Utilising multiple combinations of escape routes, weather and fuel inputs based on the 2007 Zaca fire in California, USA, we created trigger buffers for firefighter evacuations on foot, by engine and by bulldozer. Trigger buffer sensitivity to evacuation mode and expected weather and fuel conditions was examined.
Shorter-term drought and fire-danger-rating indices (Energy Release Component and monthly precipitation totals) had strong correlations with area burned and number of large fires in the western US during 1984–2008, likely due to associations with dead fuel moistures. Longer-term indices (Palmer Drought Severity Index and 24-month Standardised Precipitation Index) showed weak correlations.
This study compares fire intensities defined by MODIS Fire Radiative Power (MODIS FRP) products with Landsat-derived spectral burn severity indices for 16 fires. We conclude that distributional measures of MODIS FRP have the potential to be used in predicting potential high severity and long-term negative ecological effects (as indicated by RdNBR in this case) when applied at the extended spatial–temporal scales of individual wildland fire events.
Wildfires often cause major economic and ecological impacts. Therefore, accurate predictions of tree mortality and regeneration following fire are crucial for management decisions. Our results suggest that it is possible to accurately predict the most common post-fire responses of Mediterranean species based on simple fire and tree characteristics.
The short-term effect of smoke from combustion of two fuel types on grapevines was determined by measuring leaf gas exchange before and after exposure of leaves to smoke. There was little to no effect on some varieties and all had recovered to pre-exposure levels within 48 h.
Frogs were surveyed in fire prone wetlands in eastern Australia over different temporal and spatial scales. The dynamic and adaptive responses observed within the acid frog species studied demonstrate resilience to fire processes in these fire prone habitats, as well as adaptive capacity and resilience to future climate change.
The Rothermel surface fire spread model includes a wind limit, above which rate of spread is constant. Examination of the 1967 Tasmania data and more recent grassfire data indicates that the limit is too restrictive. We recommend that the limit not be imposed.
Two laboratory empirical techniques to determine how the rate of spread of straight fire fronts in inclined terrain and still air depends on the orientation of the front are developed and compared. The results challenge a common assumption of forest fire models and show up problems with the steadiness of closed fronts.
An experimental study to analyse the burning of firebrands in a varying flow velocity and direction was carried out to assess the validity of using mass loss coefficients determined in similar tests with pure static conditions. It was concluded that mass loss coefficients found in pure static conditions cannot be applied in such varying conditions.
It is observed that in normal ignition conditions, live fuels do not support a spreading fire if not complemented by dry fuels. Based on an experimental study this paper proposes empirical models to find a threshold value of dry fuel mass concentration for which the fire front will spread and to estimate its influence on the rate of spread.
Regional scale relationships between area burned and climate across western United States for 1984–2010 exhibited stronger correlations to biophysical variables during the fire season than antecedent climate or temperature, precipitation and longer-term drought during the fire season.