HISTORY OF A SMALL CROWN FIRE

1964 ◽  
Vol 40 (2) ◽  
pp. 202-209 ◽  
Author(s):  
C. E. Van Wagner
Keyword(s):  
Red Pine ◽  
Energy Output ◽  
Crown Fire ◽  
Fire Behaviour ◽  
Pine Plantation ◽  
Rate Of Spread ◽  
Fast Spreading ◽  
History Of ◽  
Slow Moving ◽  
Extreme Fire

An 80-foot-square plot in a red pine plantation was burned at extreme fire danger as part of a study of fire behaviour and effect. When the wind reversed its direction, the original slow-moving back-fire changed within a few minutes to a fast-spreading crown fire. The transition from surface to crowns is described in terms of rate of spread, fuel weight consumed and energy output.

scholarly journals DESCRIBING FOREST FIRES — OLD WAYS AND NEW

1965 ◽  
Vol 41 (3) ◽  
pp. 301-305 ◽  
Author(s):  
C. E. van Wagner
Keyword(s):  
Forest Fires ◽  
Quantitative Measure ◽  
Verbal Description ◽  
Energy Output ◽  
Fire Behaviour ◽  
Fire Control ◽  
Linear Rate ◽  
Rate Of Spread ◽  
Fire Front ◽  
In Fire

This article deals with several ways of describing forest fires and their limitations. The simplest and oldest way is by simple verbal description. Then came the combination of rate of spread and resistance to control. The best quantitative measure of fire behaviour, however, is the rate of energy output per unit of fire front, quoted in conjunction with the linear rate of spread. If the full benefits of advances in fire control technology are to be realized, wider use of the energy output concept will probably be necessary, first among fire researchers and eventually among fire control people.

scholarly journals Development of a Field Deployable Firebrand Flux and Condition Measurement System

2020 ◽  
Author(s):  
Simone Zen ◽  
Jan C. Thomas ◽  
Eric V. Mueller ◽  
Bhisham Dhurandher ◽  
Michael Gallagher ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Time History ◽  
Infrared Camera ◽  
Thermal Conditions ◽  
Particle Characterization ◽  
Fire Dynamics ◽  
Rate Of Spread ◽  
New Instrument ◽  
History Of

AbstractA new instrument to quantify firebrand dynamics during fires with particular focus on those associated with the Wildland-Urban Interface (WUI) has been developed. During WUI fires, firebrands can ignite spot fires, which can rapidly increase the rate of spread (ROS) of the fire, provide a mechanism by which the fire can pass over firebreaks and are the leading cause of structure ignitions. Despite this key role in driving wildfire dynamics and hazards, difficulties in collecting firebrands in the field and preserving their physical condition (e.g. dimensions and temperature) have limited the development of knowledge of firebrand dynamics. In this work we present a new, field-deployable diagnostic tool, an emberometer, designed to provide measurement of firebrand fluxes and information on both the geometry and the thermal conditions of firebrands immediately before deposition by combining a visual and infrared camera. A series of laboratory experiments were conducted to calibrate and validate the developed imaging techniques. The emberometer was then deployed in the field to explore firebrand fluxes and particle conditions for a range of fire intensities in natural pine forest environments. In addition to firebrand particle characterization, field observations with the emberometer enabled detailed time history of deposition (i.e. firebrand flux) relative to concurrent in situ fire behaviour observations. We highlight that deposition was characterised by intense, short duration “showers” that can be reasonably associated to spikes in the average fire line intensity. The results presented illustrate the potential use of an emberometer in studying firebrand and spot fire dynamics.

scholarly journals Evaluating Crown Fire Rate of Spread Predictions from Physics-Based Models

2015 ◽  
Vol 52 (1) ◽  
pp. 221-237 ◽  
Author(s):  
C. M. Hoffman ◽  
J. Canfield ◽  
R. R. Linn ◽  
W. Mell ◽  
C. H. Sieg ◽  
...  
Keyword(s):  
Crown Fire ◽  
Rate Of Spread

Evaluating a model for predicting active crown fire rate of spread using wildfire observations

2006 ◽  
Vol 36 (11) ◽  
pp. 3015-3028 ◽  
Author(s):  
Martin E Alexander ◽  
Miguel G Cruz
Keyword(s):  
Fire Management ◽  
Model Performance ◽  
The United States ◽  
Fire Research ◽  
Management Decision ◽  
Crown Fire ◽  
Predictive Capacity ◽  
Data Set ◽  
Rate Of Spread ◽  
Spread Model

We evaluated the predictive capacity of a rate of spread model for active crown fires (M.G. Cruz, M.E. Alexander, and R.H. Wakimoto. 2005. Can. J. For. Res. 35: 1626–1639) using a relatively large (n = 57) independent data set originating from wildfire observations undertaken in Canada and the United States. The assembled wildfire data were characterized by more severe burning conditions and fire behavior in terms of rate of spread and the degree of crowning activity than the data set used to parameterize the crown fire rate of spread model. The statistics used to evaluate model adequacy showed good fit and a level of uncertainty considered acceptable for a wide variety of fire management and fire research applications. The crown fire rate of spread model predicted 42% of the data with an error lower then ±25%. Mean absolute percent errors of 51% and 60% were obtained for Canadian and American wildfires, respectively. The characteristics of the data set did not allow us to determine where model performance was weaker and consequently identify its shortcomings and areas of future improvement. The level of uncertainty observed suggests that the model can be readily utilized in support of operational fire management decision making and for simulations in fire research studies.

scholarly journals Update on the Growth and Yield of the Rockland Red Pine Plantation

1982 ◽  
Vol 58 (5) ◽  
pp. 211-212 ◽  
Author(s):  
F. W. von Althen ◽  
W. M. Stiell
Keyword(s):  
Red Pine ◽  
Growth And Yield ◽  
Pine Plantation

Estimation de la production de jeunes plantations de pin rouge et de pin gris du sud du Québec

1976 ◽  
Vol 6 (4) ◽  
pp. 478-486 ◽  
Author(s):  
H. A. Bolghari
Keyword(s):  
Multiple Regression ◽  
Jack Pine ◽  
Red Pine ◽  
Pine Plantations ◽  
Regression Equations ◽  
Pine Plantation ◽  
South Shore ◽  
Pine Stands ◽  
Natural Stands ◽  
St Lawrence River

Multiple regression equations have been developed to predict yield from young red pine and jack pine plantations. Data from 446 sample plots representing young red pine and jack pine stands located on the south shore of the St. Lawrence River between Quebec and Montreal were analysed. The red pine plantation yielded more than the jack pine. However, in plantation both species yield more than in natural stands. Taking into account the age and spacing of the sampled plantations, the equation obtained can provide information on yield of red pine and jack pine stands the maximum spacing of which is 3 × 3 m, up to the age of 45 and 35 years respectively. The equations will allow the construction of preliminary yield tables for both species.

Instantaneous spatio-temporal rate of spread of fast spreading wildfires - a new approach from visible and thermal image processing

2021 ◽  
Author(s):  
Benjamin Schumacher ◽  
Katharine Melnik ◽  
Marwan Katurji ◽  
Veronica Clifford ◽  
Jiawei Zhang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
New Zealand ◽  
Stand Structure ◽  
Fire Severity ◽  
Thermal Infrared ◽  
Fire Spread ◽  
New Approach ◽  
Rate Of Spread ◽  
Fast Spreading ◽  
Fire Experiments

<p>The rate of spread (ROS) of wildfires is an important parameter for understanding fire-atmospheric interactions and developing fire-spread models, but it is also vital for firefighting operations to ensure the safety of firefighters (Plucinski 2017, Stow 2019). Spatial ROS observations are usually carried out by using visible and thermal satellite imagery of wildfires estimating the ROS on a time scale of hours to days for large fires (>100 ha) or repeated passing with an airborne thermal infrared imager for higher spatial and temporal resolution (Viedma et al. 2015, Stow 2014). For fire experiments in highly controlled conditions like laboratory fires or during light fuel prescribed burns, ROS estimation usually involves lag-correlation of temperature point measurements (Finney 2010, Johnston 2018). However, these methodologies are not applicable to fast-spreading grass or bush fires because of their temporal and spatial limitations. Instantaneous spatial ROS of these fires is needed to understand rapid changes in connection with the three major drivers of the fire: fuel, topography and atmospheric forcings.</p><p>We are presenting a new approach towards a spatial ROS product which includes newly developed image tracking methods based on thermal and visible imagery collected from unmanned aerial vehicles to estimate instantaneous, spatial ROS of fast spreading grass or bush fires. These techniques were developed using imagery from prescribed wheat-stubble burns carried out in Darfield, New Zealand in March 2018 (Finney 2018). Results show that both the visible and thermal tracking techniques produce similar mean ROS; however they differ in limitations and advantages. The visible-spectrum tracking method clearly identifies the flaming zone and provides accurate ROS measurements especially at the fire front. The thermal tracking technique is superior when resolving dynamics and ROS within the flaming zone because it resolves smaller scale structures within the imagery.</p><p> </p><p>References:</p><p>Finney, M. et al. 2010: An Examination of Fire Spread Thresholds in Discontinuous Fuel Beds.” International Journal of Wildland Fire, 163–170.</p><p>Finney, M. et al. 2018: New Zealand prescribed fire experiments to test convective heat transfer in wildland fires. In Advances in Forest Fire Research, Imprensa da Universidade de Coimbra: Coimbra, 2018.</p><p>Johnston, J. M., et al. 2018:  Flame-Front Rate of Spread Estimates for Moderate Scale Experimental Fires are Strongly Influenced by Measurement Approach. Fire 1: 16–17</p><p>Plucinski M., et al. 2017: Improving the reliability and utility of operational bushfire behaviour predictions in Australian vegetation. Environmental Modelling & Software 91, 1-12.</p><p>Stow, D., et al. 2014: Measuring Fire Spread Rates from Repeat PassAirborne Thermal Infrared Imagery. Remote Sensing Letters 5: 803–881.</p><p>Stow, D., et al. 2019: Assessing uncertainty and demonstrating potentialfor estimating fire rate of spread at landscape scales based on time sequential airbornethermal infrared imaging, International Journal of Remote Sensing, 40:13, 4876-4897</p><p>Viedma, O., et al. 2015:  Fire Severity in a Large Fire in a Pinus Pinaster Forest Is Highly Predictable from Burning Conditions, Stand Structure, and Topography. Ecosystems18: 237–250.</p>

A NEW ASYMPTOMATIC TYPE III VARIANT OF ANTITHROMBIN III WITH DECREASE HEPARIN COFACTOR ACTIVITY : AT III AMIENS

1987 ◽  
Author(s):  
B ROUSSEL ◽  
J DIEVAL ◽  
S GROSS ◽  
J F CLAISSE ◽  
J DELOBEL
Keyword(s):  
Factor Xa ◽  
Normal Range ◽  
Normal Pattern ◽  
Type Iii ◽  
Crossed Immunoelectrophoresis ◽  
At Iii ◽  
History Of ◽  
Routine Laboratory Examination ◽  
Slow Moving ◽  
Cofactor Activity

A qualitative abnormality of AT III suggested by the discrepancy between a normal level of AT III antigen (0,33 g/1) and a decreased heparin cofactor activity (60 % of normal) was discovered in a 37 years old woman during a routine laboratory examination for oral contraceptive. The propositus was asymptomatic as she did not developpe any thrombo-embolic disease during three previous pregnancies. There was no familial history of thrombo-embolism. The AT III level measured by radial immuno-diffusion was within the normal range. The progressive anti factor lia and anti factor Xa activities (chromogenic substrates CBS 3 447 and CBS 3 139) were normal (92 % and 100 %). Plasma and serum crossed immunoelectrophoresis (CIE) showed a normal pattern. In the presence of heparin, anti factor Xa and anti factor Xa activities were decreased (60 % and 45 %); Plasma and serum crossed immunoelectrophoresis showed an abnormal slow moving peak exhibiting the inhability of the molecule to bind completely to heparin. CIE with various other glycosaminoglycans are on experiments.Familial study revealed that the daughter of the propositus was carrying the same molecular abnormality.We conclude that AT III Amiens is an hereditary type III variant.

Sign in / Sign up

Export Citation Format

Share Document