Development and testing of models for predicting crown fire rate of spread in conifer forest stands

2005 ◽  
Vol 35 (7) ◽  
pp. 1626-1639 ◽  
Author(s):  
Miguel G Cruz ◽  
Martin E Alexander ◽  
Ronald H Wakimoto
Keyword(s):  
Bulk Density ◽  
Fire Behavior ◽  
Fire Regimes ◽  
Management Decision ◽  
Crown Fire ◽  
Conifer Forest ◽  
Data Set ◽  
Rate Of Spread ◽  
Spread Model ◽  
Canopy Bulk Density

The rate of spread of crown fires advancing over level to gently undulating terrain was modeled through nonlinear regression analysis based on an experimental data set pertaining primarily to boreal forest fuel types. The data set covered a significant spectrum of fuel complex and fire behavior characteristics. Crown fire rate of spread was modeled separately for fires spreading in active and passive crown fire regimes. The active crown fire rate of spread model encompassing the effects of 10-m open wind speed, estimated fine fuel moisture content, and canopy bulk density explained 61% of the variability in the data set. Passive crown fire spread was modeled through a correction factor based on a criterion for active crowning related to canopy bulk density. The models were evaluated against independent data sets originating from experimental fires. The active crown fire rate of spread model predicted 42% of the independent experimental crown fire data with an error lower then 25% and a mean absolute percent error of 26%. While the models have some shortcomings and areas in need of improvement, they can be readily utilized in support of fire management decision making and other fire research studies.

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 Evaluating the 3-m tree crown spacing guideline for the prevention of crowning wildfires in lodgepole pine forests, Alberta

2020 ◽  
Vol 96 (02) ◽  
pp. 165-173
Author(s):  
Martin E. Alexander ◽  
Miguel G. Cruz
Keyword(s):  
Bulk Density ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Pine Forests ◽  
Crown Fire ◽  
Conifer Forest ◽  
Fire Propagation ◽  
Current State ◽  
General Recommendation ◽  
Canopy Bulk Density

A 3-m between crown spacing is a commonly cited criterion found in the wildland-urban interface fire literature for minimizing the likelihood of a fully-developed crown fire from occurring in a conifer forest on level terrain. The validity of this general recommendation is examined here in light of our current state-of-knowledge regarding crown fire propagation in relation to canopy bulk density. Given the characteristics of the overstory structure for 20 lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands located in Alberta, as sourced from the literature, the canopy fuel properties following a virtual thinning to a 3-m crown spacing and then to a targeted canopy bulk density of 0.05 kg/m3 were computed. On the basis of these computations, crown fire potential was then analyzed and interpreted. The conclusion reached is that, in the majority of cases, a less widely spaced stand would be adequate for preventing crown fire development in lodgepole pine forests.

Flatland in flames: a two-dimensional crown fire propagation model

2009 ◽  
Vol 18 (5) ◽  
pp. 527 ◽  
Author(s):  
James D. Dickinson ◽  
Andrew P. Robinson ◽  
Paul E. Gessler ◽  
Richy J. Harrod ◽  
Alistair M. S. Smith
Keyword(s):  
Bulk Density ◽  
Original Data ◽  
Propagation Model ◽  
Crown Fire ◽  
Wagner Model ◽  
Fire Propagation ◽  
Rate Of Spread ◽  
Proposed Model ◽  
Foliar Biomass ◽  
Canopy Bulk Density

The canopy bulk density metric is used to describe the fuel available for combustion in crown fire models. We propose modifying the Van Wagner crown fire propagation model, used to estimate the critical rate of spread necessary to sustain active crown fire, to use foliar biomass per square metre instead of canopy bulk density as the fuel input. We tested the efficacy of our proposed model by comparing predictions of crown fire propagation with Van Wagner’s original data. Our proposed model correctly predicted each instance of crown fire presented in the seminal study. We then tested the proposed model for statistical equivalence to the original Van Wagner model using two contemporary techniques to parameterize canopy bulk density. We found the proposed and original models to be statistically equivalent when canopy bulk density was parameterized using the method incorporated in the Fire and Fuels Extension to the Forest Vegetation Simulator (difference < 0.5 km h–1, α = 0.05, n = 2626), but not when parameterized using the method of Cruz and others. Use of foliar biomass per unit area in the proposed model makes for more accurate and easily obtained fuel estimates without sacrificing the utility of the Van Wagner model.

Estimating canopy fuel characteristics for predicting crown fire potential in common forest types of the Atlantic Coastal Plain, USA

2018 ◽  
Vol 27 (11) ◽  
pp. 742 ◽  
Author(s):  
Anne G. Andreu ◽  
John I. Blake ◽  
Stanley J. Zarnoch
Keyword(s):  
Bulk Density ◽  
Coastal Plain ◽  
Canopy Cover ◽  
Atlantic Coastal Plain ◽  
Theoretic Approach ◽  
Crown Fire ◽  
Prescribed Burns ◽  
Stand Height ◽  
Atlantic Coastal ◽  
Canopy Bulk Density

We computed four stand-level canopy stratum variables important for crown fire modelling – canopy cover, stand height, canopy base height and canopy bulk density – from forest inventory data. We modelled the relationship between the canopy variables and a set of common inventory parameters – site index, stem density, basal area, stand age or stand height – and number of prescribed burns. We used a logistic model to estimate canopy cover, a linear model to estimate the other canopy variables, and the information theoretic approach for model selection. Coefficients of determination across five forest groups were 0.72–0.91 for stand height, 0.36–0.83 for canopy base height, 0.39–0.80 for canopy cover, and 0.63–0.78 for canopy bulk density. We assessed crown fire potential (1) for several sets of environmental conditions in all seasons, and (2) with increasing age, density and number of prescribed burns using our modelled canopy bulk density and canopy base height variables and local weather data to populate the Crown Fire Initiation and Spread model. Results indicated that passive crown fire is possible in any season in Atlantic coastal plain pine stands with heavy surface fuel loads and active crown fire is most probable in infrequently burned, dense stands at low fuel moistures.

Spatial fuel data products of the LANDFIRE Project

2009 ◽  
Vol 18 (3) ◽  
pp. 250 ◽  
Author(s):  
Matthew C. Reeves ◽  
Kevin C. Ryan ◽  
Matthew G. Rollins ◽  
Thomas G. Thompson
Keyword(s):  
Bulk Density ◽  
Vegetation Structure ◽  
Fire Regime ◽  
Fire Behavior ◽  
The United States ◽  
Surface Fire ◽  
Spatial Coverage ◽  
Data Products ◽  
Fuel Models ◽  
Canopy Bulk Density

The Landscape Fire and Resource Management Planning Tools (LANDFIRE) Project is mapping wildland fuels, vegetation, and fire regime characteristics across the United States. The LANDFIRE project is unique because of its national scope, creating an integrated product suite at 30-m spatial resolution and complete spatial coverage of all lands within the 50 states. Here we describe development of the LANDFIRE wildland fuels data layers for the conterminous 48 states: surface fire behavior fuel models, canopy bulk density, canopy base height, canopy cover, and canopy height. Surface fire behavior fuel models are mapped by developing crosswalks to vegetation structure and composition created by LANDFIRE. Canopy fuels are mapped using regression trees relating field-referenced estimates of canopy base height and canopy bulk density to satellite imagery, biophysical gradients and vegetation structure and composition data. Here we focus on the methods and data used to create the fuel data products, discuss problems encountered with the data, provide an accuracy assessment, demonstrate recent use of the data during the 2007 fire season, and discuss ideas for updating, maintaining and improving LANDFIRE fuel data products.

Canopy bulk density and canopy base height equations for assessing crown fire hazard in Pinus radiata plantations

2011 ◽  
Vol 41 (4) ◽  
pp. 839-850 ◽  
Author(s):  
Ana Daría Ruiz-González ◽  
Juan Gabriel Álvarez-González
Keyword(s):  
Bulk Density ◽  
Pinus Radiata ◽  
Fire Hazard ◽  
Direct Action ◽  
Quantitative Information ◽  
Wildlife Habitat ◽  
Vertical Profiles ◽  
Crown Fire ◽  
Crown Fires ◽  
Canopy Bulk Density

Crown fires combine high rates of spread, flame lengths, and intensities, making it virtually impossible to control them by direct action and having significant impact on soils, vegetation, and wildlife habitat. For these reasons, fire managers have great interest in preventive silviculture of forested landscapes to avoid the initiation and propagation of crown fires. The minimum conditions necessary to initiate and propagate crown fires are assumed to be strongly influenced by the stand structural variables canopy bulk density (CBD) and canopy base height (CBH). However, there is a lack of quantitative information on these variables and how to estimate them. To characterize the aerial fuel layers of Pinus radiata D. Don, the vertical profiles of canopy fuel in 180 sample plots of pure and even-aged P. radiata plantations were analysed. Effective CBD and CBH were obtained from the vertical profiles, and equations relating these variables to common stand variables were fitted simultaneously. Inclusion of the fitted equations in existing dynamic growth models, together with the use of current fire behaviour and hazard prediction tools, will provide a decision support system for assessing the crown fire potential of different silvicultural alternatives for this species.

Mediterranean fuel models and potential fire behaviour in Greece

2002 ◽  
Vol 11 (2) ◽  
pp. 127 ◽  
Author(s):  
A. P. Dimitrakopoulos
Keyword(s):  
Fire Behavior ◽  
Pine Forests ◽  
Fuel Load ◽  
Average Height ◽  
Litter Layer ◽  
Data Set ◽  
Rate Of Spread ◽  
Fuel Models ◽  
Tall Shrub ◽  
Mediterranean Pine

The Mediterranean vegetation types of Greece were classified into typical fuel models by measuring the following fuel parameters in 181 representative natural fuel complexes: 1-h, 10-h, 100-h and 1000-h fuel loads; foliage load; litter load and depth; total fuel load; average height and soil cover of the herbaceous, small shrub (up to 0.5 m) and tall shrub (0.5-3.0 m) vegetation layers. The data set was statistically analysed by a two-stage clustering procedure that produced seven distinct fuel models: two for evergreen-sclerophyllous shrublands (maquis), one for kermes oak shrublands, two for phrygana, one for grasslands and one for the litter layer of Mediterranean pine forests. The indicative range (upper and lower limit) of potential fire behavior for every fuel model was calculated with the BEHAVE fire behavior prediction system, using as inputs the specific fuel parameter values of every model. The shrubland fuel models resulted in fires with high intensity and rate of spread, while the phrygana and grassland models in fast fires of medium to low intensity. The litter layer of the pine forests provided the least severe burning conditions.

Conditions for the start and spread of crown fire

1977 ◽  
Vol 7 (1) ◽  
pp. 23-34 ◽  
Author(s):  
C. E. Van Wagner
Keyword(s):  
Heat Transfer ◽  
Bulk Density ◽  
Combustion Zone ◽  
Ground Surface ◽  
Conifer Forests ◽  
Crown Fire ◽  
Surface Phase ◽  
Conifer Forest ◽  
Crown Fires

Some theory and observations are presented on the factors governing the start and spread of crown fire in conifer forests. Crown fires are classified in three ways according to the degree of dependence of the crown phase of the fire on the ground surface phase. The crown fuel is pictured as a layer of uniform bulk density and height above ground. Simple criteria are presented for the initiation of crown combustion and for the minimum rates of spread and heat transfer into the crown combustion zone at which the crown fire will spread. The theory is partially supported by some observations in four kinds of conifer forest.

Evaluating regression model estimates of canopy fuel stratum characteristics in four crown fire-prone fuel types in western North America

2012 ◽  
Vol 21 (2) ◽  
pp. 168 ◽  
Author(s):  
Miguel G. Cruz ◽  
Martin E. Alexander
Keyword(s):  
North America ◽  
Bulk Density ◽  
Ponderosa Pine ◽  
Stand Structure ◽  
Coniferous Forest ◽  
Fuel Load ◽  
Regression Equations ◽  
Western North America ◽  
Crown Fire ◽  
Canopy Bulk Density

Two evaluations were undertaken of the regression equations developed by M. Cruz, M. Alexander and R. Wakimoto (2003, International Journal of Wildland Fire 12, 39–50) for estimating canopy fuel stratum characteristics from stand structure variables for four broad coniferous forest fuel types found in western North America. The first evaluation involved a random selection of 10 stands each from the four datasets used in the original study. These were in turn subjected to two simulated thinning regimes (i.e. 25 and 50% basal area removal). The second evaluation involved a completely independent dataset for ponderosa pine consisting of 16 stands sampled by T. Keyser and F. Smith (2010, Forest Science 56, 156–165). Evaluation statistics were comparable for the thinning scenarios and independent evaluations. Mean absolute percentage errors varied between 13.8 and 41.3% for canopy base height, 5.3 and 67.9% for canopy fuel load, and 20.7 and 71% for canopy bulk density. Bias errors were negligible. The results of both evaluations clearly show that the stand-level models of Cruz et al. (2003) used for estimating canopy base height, canopy fuel load and canopy bulk density in the assessment of crown fire potential are, considering their simplicity, quite robust.

Testing the Effect of Fuel Consumption on Fire Spread Rate

1995 ◽  
Vol 5 (3) ◽  
pp. 143 ◽  
Author(s):  
RS McAlpine
Keyword(s):  
Fuel Consumption ◽  
Fire Behavior ◽  
Fire Spread ◽  
Data Sets ◽  
Behavior Prediction ◽  
Spread Rate ◽  
Data Set ◽  
Weak Relationship ◽  
Rate Of Spread ◽  
Fire Front

It has been theorized that the amount of fuel involved in a fire front can influence the rate of spread of the fire. Three data sets are examined in an attempt to prove this relationship. The first, a Canadian Forest Service database of over 400 experimental, wild, and prescribed fires showed a weak relationship in some fuel complexes. The second, a series of field experimental fires conducted to isolate the relationship, showed a small effect. The final data set, from a series of 47 small plots (3m x 3m) burned with a variety of fuel loadings, also show a weak relationship. While a relationship was shown to exist, it is debatable whether it should be included in a fire behavior prediction system. Inherent errors associated with predicting fuel consumption can be compounded, causing additional, more critical, errors with the derived fire spread rate.

Sign in / Sign up

Export Citation Format

Share Document