Modeling Wildland Fire Containment With Uncertain Flame Length and Fireline Width

1993 ◽  
Vol 3 (3) ◽  
pp. 179 ◽  
Author(s):  
R Mees ◽  
D Strauss ◽  
R Chase
Keyword(s):  
Mathematical Model ◽  
Wildland Fire ◽  
Flame Length ◽  
Fire Fighting ◽  
Optimum Allocation ◽  
Fire Containment

We describe a mathematical model for the probability that a fireline succeeds in containing a fire. The probability increases as the fireline width increases, and also as the fire's flame length decreases. More interestingly, uncertainties in width and flame length affect the computed containment probabilities, and can thus indirectly affect the optimum allocation of fire-fighting resources. Uncertainty about the fireline width that will be produced can often affect containment chances as much as uncertainty in flame length.

Minimizing the cost of wildland fire suppression: a model with uncertainty in predicted flame length and fire-line width produced

1994 ◽  
Vol 24 (6) ◽  
pp. 1253-1259 ◽  
Author(s):  
Romain Mees ◽  
David Strauss ◽  
Richard Chase
Keyword(s):  
Line Width ◽  
Wildland Fire ◽  
Fire Suppression ◽  
Flame Length ◽  
Burned Area ◽  
Expected Cost ◽  
Control Time ◽  
The Cost ◽  
Attack Strategy

We describe a model that estimates the optimal total expected cost of a wildland fire, given uncertainty in both flame length and fire-line width produced. In the model, a sequence of possible fire-line perimeters is specified, each with a forecasted control time. For a given control time and fire line, the probability of containment of the fire is determined as a function of the fire-fighting resources available. Our procedure assigns the resources to the fire line so as to minimize the total expected cost. A key feature of the model is that the probabilities reflect the degree of uncertainty in (i) the width of fire line that can be built with a given resource allocation, and (ii) the flame length of the fire. The total expected cost associated with a given choice of fire line is the sum of: the loss or gain of value of the area already burned; the cost of the resources used in the attack; and the expected loss or gain of value beyond the fire line. The latter is the product of the probability that the chosen attack strategy fails to contain the fire and the value of the additional burned area that would result from such a failure. The model allows comparison of the costs of the different choices of fire line, and thus identification of the optimal strategy. A small case study is used to illustrate the procedure.

Down-Canyon Afternoon Winds 1

1961 ◽  
Vol 42 (8) ◽  
pp. 527-542 ◽  
Author(s):  
Mark J. Schroeder
Keyword(s):  
Sierra Nevada ◽  
Short Range ◽  
Wildland Fire ◽  
Fire Fighting ◽  
Lower Atmosphere ◽  
San Diego County ◽  
Fire Control ◽  
Early Afternoon ◽  
Early Fall ◽  
The Stability

In east-facing canyons in the coastal mountains of California, the daytime thermal up-canyon winds are frequently replaced, usually in early afternoon, by a moderately strong down-canyon wind. The same type of wind has also been noted in the western foothills of the Sierra Nevada. This shift in the wind to down canyon is important in wildland fire control and has been a factor in some fire-fighting fatalities. Results of a fire-climate survey conducted in northwestern San Diego County to study these winds show that, in the summer and early fall of 1959, winds switched to down canyon in the afternoon on about one-quarter of the days. From the surface records and a few double-theodolite and airplane observations, a diagrammatic model of this phenomenon has been constructed. The stability of the lower atmosphere along the coast was closely related to the occurrence of down-canyon winds in the area studied. The possibility of making short-range predictions exists by using this relationship along with other considerations.

scholarly journals Wettability and extinguishing power of different wetting composition for wildland fire fighting

2014 ◽  
pp. 1592-1598
Author(s):  
Joanna Rakowska ◽  
Bożenna Porycka ◽  
Katarzyna Radwan ◽  
Ryszard Szczygieł ◽  
Mirosław Kwiatkowski
Keyword(s):  
Wildland Fire ◽  
Fire Fighting

scholarly journals MODELING THE WORK FLOW OF CUT-OUT SPHERICAL DISKS WITH HYDRAULIC DRIVE FOR FIRE-FIGHTING SOIL-THROWER

2020 ◽  
Vol 10 (1) ◽  
pp. 185-192
Author(s):  
Maksim Gnusov ◽  
Mikhail Drapalyuk ◽  
P. Popikov ◽  
N. Sherstyukov
Keyword(s):  
Mathematical Model ◽  
Forest Fire ◽  
Cutting Edge ◽  
Fire Fighting ◽  
Dynamic State ◽  
Soil Environment ◽  
Spherical Elements ◽  
Working Bodies ◽  
The Mathematical Model ◽  
The Relationship

In this article, considerable attention is paid to the method of mathematical creation of a structurally complex soil environment with vegetation. Structural and technological parameters of the interaction of the working bodies of the fire-fighting soil thrower with soil have been determined using a simulation-physical-mathematical model of the spherical disk relationship with the soil environment. The disk is equipped with a cutting edge with semicircular cuts. The mathematical model presents complex geometry of all forms of active work planes, as well as the relationship of the working bodies with soil elements. Surfaces of complex construction in the process of applying the finite element method have been transformed into a large number of simplified planar figures. The soil in the simulation physical-mathematical model is described as a complex system of a large number of spherical elements, determinately connecting with each other, as well as with the working planes of the machine. It has been determined that the relationship between the soil particles during deformation is viscoelastic in its nature. The calculation of forces is presented in the form of an algorithm for the interaction of elements on each other in relation to the distance of their location. The equations of motion are used that describe the change in the dynamic state of the soil over time. The movement of the working bodies of the unit, including spherical disk working bodies with cutouts in the framework of the mathematical model, has been considered in the simulated space, described as a parallelepiped. The ability to simulate the interaction of the working bodies of a forest fire soil-throwing machine with a working medium, including plant roots, which are located next to each other in the form of spherical elements in the geometric region. The task of increasing the efficiency of the forest fire-fighting soil-throwing machine when laying fire strips has been solved by improving the quality of preparing the soil shaft with spherical hydraulic disks equipped with a cutting edge with semicircular cuts, which are subsequently taken by thrower-cutters and feed the soil flow in a given direction

Interdependencies between flame length and fireline intensity in predicting crown fire initiation and crown scorch height

2012 ◽  
Vol 21 (2) ◽  
pp. 95 ◽  
Author(s):  
Martin E. Alexander ◽  
Miguel G. Cruz
Keyword(s):  
Wildland Fire ◽  
Stem Bark ◽  
Flame Length ◽  
Flame Height ◽  
Crown Fire ◽  
Fire Behaviour ◽  
Surface Fire ◽  
Crown Scorch ◽  
Fire Initiation ◽  
Bark Char

This state-of-knowledge review examines some of the underlying assumptions and limitations associated with the inter-relationships among four widely used descriptors of surface fire behaviour and post-fire impacts in wildland fire science and management, namely Byram’s fireline intensity, flame length, stem-bark char height and crown scorch height. More specifically, the following topical areas are critically examined based on a comprehensive review of the pertinent literature: (i) estimating fireline intensity from flame length; (ii) substituting flame length for fireline intensity in Van Wagner’s crown fire initiation model; (iii) the validity of linkages between the Rothermel surface fire behaviour and Van Wagner’s crown scorch height models; (iv) estimating flame height from post-fire observations of stem-bark char height; and (v) estimating fireline intensity from post-fire observations of crown scorch height. There has been an overwhelming tendency within the wildland fire community to regard Byram’s flame length–fireline intensity and Van Wagner’s crown scorch height–fireline intensity models as universal in nature. However, research has subsequently shown that such linkages among fire behaviour and post-fire impact characteristics are in fact strongly influenced by fuelbed structure, thereby necessitating consideration of fuel complex specific-type models of such relationships.

Corrigendum to: Interdependencies between flame length and fireline intensity in predicting crown fire initiation and crown scorch height

2017 ◽  
Vol 26 (4) ◽  
pp. 345 ◽  
Author(s):  
Martin E. Alexander ◽  
Miguel G. Cruz
Keyword(s):  
Wildland Fire ◽  
Stem Bark ◽  
Flame Length ◽  
Flame Height ◽  
Crown Fire ◽  
Fire Behaviour ◽  
Surface Fire ◽  
Crown Scorch ◽  
Fire Initiation ◽  
Bark Char

This state-of-knowledge review examines some of the underlying assumptions and limitations associated with the inter-relationships among four widely used descriptors of surface fire behaviour and post-fire impacts in wildland fire science and management, namely Byram's fireline intensity, flame length, stem-bark char height and crown scorch height. More specifically, the following topical areas are critically examined based on a comprehensive review of the pertinent literature: (i) estimating fireline intensity from flame length; (ii) substituting flame length for fireline intensity in Van Wagner's crown fire initiation model; (iii) the validity of linkages between the Rothermel surface fire behaviour and Van Wagner's crown scorch height models; (iv) estimating flame height from post-fire observations of stem-bark char height; and (v) estimating fireline intensity from post-fire observations of crown scorch height. There has been an overwhelming tendency within the wildland fire community to regard Byram's flame length–fireline intensity and Van Wagner's crown scorch height–fireline intensity models as universal in nature. However, research has subsequently shown that such linkages among fire behaviour and post-fire impact characteristics are in fact strongly influenced by fuelbed structure, thereby necessitating consideration of fuel complex specific-type models of such relationships.

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