In historically fire-dependent upland oak forests of the eastern U.S., anthropogenic fire exclusion is likely causing a hypothesized feedback loop between an increase in fire-sensitive species and self-promoting, fireree conditions at the detriment of oak regeneration. This study determined how shifts from oaks (Quercus stellata and Q. falcata) to fire-sensitive non-oaks (Carya spp., Liquidambar styraciflua, and Ulmus alata) affected flammability and related processes that consequently determine species composition. Using treatments of increasing non-oak leaf litter, experimental burns were conducted and flammability measured under field conditions, and a laboratory litter moisture desorption experiment was conducted. As litter composition shifted from oak-dominated to non-oak-dominated, flammability decreased (R2 = 0.59, P < 0.001) and moisture-holding capacity increased (R2=0.88, P<0.001). To prevent further shifts toward fireree conditions and loss of economically and ecologically valuable oaks, prescribed fire should be reintroduced soon while oak maintains overstory dominance and controls forest flammability.

We report on the potential for developing long-term fire histories from chir pine (Pinus roxburghii Sarg.) forests in the Western Himalayan foothills based on a preliminary study from a stand located in the state of Uttarakhand in northern India. Rings from trees collected to develop a master skeleton plot chronology were generally complacent with false rings present during most years, but were crossdatable with only minor difficulty. The oldest tree confidently crossdated back to 1886, with good sample depth (5 trees) from 1911, which helped date the fire scars in cross-sections collected from three trees. Fire frequency as determined from fire-scar dates was high, with mean and median fire intervals of 3 years from 1938 to 2006. Fires were likely from human ignitions given the prevalence of human land use in the site. Fire scars were generally recorded at false-ring boundaries and likely represent burning during the hot, dry period in May or early June before the onset of monsoon rainfall beginning in mid-June. Although only three fire-scarred trees were sampled, this preliminary assessment shows there is a potential for additional samples from other stands to develop longer-term fire histories to better understand the role of fire in the ecology and management of chir pine throughout its range in the Himalaya region.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Clothing; manikin. Includes bibliographical references (p. 81-83).

Thesis (M.S. of B.C. & I.F.M.)--College of Architecture, Georgia Institute of Technology, 2004. Directed by Linda Thomas-Mobley. / Includes bibliographical references (leaves 69-70).

Thesis, (M.S.)--University of Wisconsin--Stout, 1998. / "December 1998" Includes bibliographical references, p. 77-79. Available on the internet at the uwstout.edu sebsite.

No description available.

Wildland fire is a natural part of the earth’s phenomenological pattern and like most natural phenomena has presented a challenge to human activity and engineering science. Wildfire presents Fire Safety Engineering with the task of developing fundamental research and designing analysis tools to address fire on a scale where interactions with atmospheric and terrestrial conditions dominate fire behavior. The research work presented in this thesis addresses a fundamental research issue involving transport processes in porous wildland fuel beds. This research project had the specific goal of developing an understanding of how transport processes affected the combustion of wildland fuels that were in the form of a porous bed. No detailed study could be found in the literature that specifically addressed how the fuel structure affected the combustion process in these types of fuels. To this end, a series of experiments were designed and carried out that approached the understanding of this problem using commonly available fire testing equipment, specifically the cone calorimeter and the FM Global Fire Propagation Apparatus. The goal of this research study and the basis for the novel and relevant contribution to the field of engineering was to conduct an experimental test series, analyze the data and examine the scalability of the results, to determine the effect of transport processes on the Heat Release Rate (HRR) of porous wildland fuels. The project concluded that flow dominates HRR in fires involving the wildland fuels tested. A dimensionless analysis of the fuel sample baskets showed consistency with well established mass transfer, fluid flow and chemical kinetic relationships. The dimensionless analysis also indicates that the experimental results should be scalable to similar configurations in larger fuel beds. One conclusion of this study was that wildland fire modeling efforts should invest in understanding flow conditions in fuel beds because this behavior dominates over the chemical kinetics of combustion for predicting HRR which is an important parameter in fire modeling.

Wildland fires are a type of vegetation fire that burn in a rural or wild landscape and affect many countries worldwide. They are an important mechanism in ecosystem maintenance, although in certain cases wildland fires can adversely affect both people and the environment. A wildland fire can interact with the surrounding topography, vegetation and weather in a complex manner, which makes microscale prediction of wildland fire behaviour difficult in many situations. This thesis focused on the application of the Weather Research and Forecast (WRF) numerical weather prediction (NWP) and WRF-Fire coupled atmosphere-fire models to investigating aspects of atmospheric interactions with wildland fire. The research covered a wide range of atmospheric scales, from a seasonal mesoscale analysis of fire weather conditions across New Zealand to a microscale analysis of complex atmosphere-fire interactions over idealised terrain. The first study investigated the suitability of WRF modelling of fire weather conditions for the 2009/10 wildland fire season in New Zealand. The WRF model horizontal grid spacing was 8 km and the model output was directly compared with near-surface fire weather conditions meaured and derived at 23 weather stations located throughout New Zealand. The analysis considered the air temperature, relative humidity, wind conditions, rainfall and the New Zealand Fire Weather Index (FWI) and Continuous Haines Index (CHI) on observed high-end fire weather days. WRF typically underpredicted the air temperatures and relative humidities, whereas it typically overpredicted the wind speeds, CHI and the number of high-end fire weather days. WRF was assessed to be unsuitable for accurately modelling particular aspects of fire weather, such as the wind speed and direction, in mountainous terrain and near complex coastlines. Further research is needed to investigate how varying the horizontal resolution in WRF affects the assessed accuracy of modelled fire weather conditions. The second study investigated the behaviour of the Haines Index (HI), CHI and FWI, and their associated atmospheric properties for the 2009/10 wildland fire season in New Zealand. The analysis demonstrated that there was a large degree of spatial variability in fire weather conditions throughout New Zealand, particularly in or near mountainous terrain. The fire weather severity was highest in the eastern South Island and appeared to be closely associated with mesoscale atmospheric processes over mountainous terrain, although the relationship between these atmospheric processes and fire weather condi- tions requires further investigation. The HI and CHI were both limited in their utility at measuring aloft fire weather conditions in high altitude regions. Finally, the fire weather conditions associated with the 36 largest wildland fires of the fire season were evaluated, although no statistical relationships were found between the wildland fire size and either the CHI or FWI. The third study investigated the fire weather conditions across the South Island associated with an extreme foehn event on 6 February 2011. Mountain waves developed in the northwesterly synoptic flow over the Southern Alps and were found to directly influence the fire weather conditions near the surface and aloft in the lee of the mountains. A hydraulic jump along the foothills of the Canterbury Plains resulted in a downslope windstorm with wind speeds exceeding 80 km/h. Further south, large amplitude mountain lee waves directly influenced the near-surface wind speeds and atmospheric stability aloft. The foehn winds were associated with peak air temperatures over 35˚C in the eastern South Island, which are significantly higher than the climatological average. The FWI indicated widespread extreme near-surface fire weather conditions in the lee of the mountains. The subsequent passge of a cold front on 7 February brought a marked reduction in fire weather severity across the South Island. The fourth study investigated atypical wildland fire behaviour on steep leeward slopes through a series of idealised WRF-Fire simulations. The analysis considered both the leeward flow characteristics over a triangular ridge line and the fire spread from an ignition point at the base of the leeward slope. The fire spread was modelled for two different fuel types and with two-way atmosphere-fire coupling both enabled and disabled. The modelled fire spread in the heavy fuel type with coupling enabled closely resembled the fire channelling wildland fire behaviour phenomenon. The initial fire spread was initially dominated by upslope fire spread to the mountain ridge line at an average rate of around 2.0 km/h. This was followed by a phase of intermittent rapid lateral fire spread close to the ridge line at a maximum rate of around 3.6 km/h. The intermittent rapid lateral fire spread was driven by strongly circulating horizontal near-surface winds that were associated with updraft-downdraft interfaces. These updraft-downdraft interfaces formed due to an interaction between the strong pyro-convection and terrain-modified winds. The presented research collectively demonstrated the versatility and effectiveness of NWP and coupled atmosphere-fire modelling for studying various aspects of atmospheric interactions with wildland fire. The research further highlighted the effects of atmospheric processes over complex terrain on fire weather conditions and wildland fire behaviour. Although three of the studies in the thesis had a regional focus on New Zealand, the research outcomes should benefit end users in fire management worldwide.

No description available.

Thesis (Ph. D.)--Victoria University (Melbourne, Vic.), 2007. / Includes bibliographical references.