Two methods for calculating wildland fire rate of forward spread

2020 ◽  
Vol 29 (3) ◽  
pp. 272 ◽  
Author(s):  
Jim S. Gould ◽  
Andrew L. Sullivan
Keyword(s):  
Wind Tunnel ◽  
Field Experiments ◽  
Prediction Models ◽  
Wildland Fire ◽  
Model Development ◽  
Laboratory Data ◽  
Fire Spread ◽  
Accurate Estimation ◽  
Spread Rate ◽  
Eucalypt Forest

Accurate estimation of a wildland fire’s progression is critical for the development of robust fire spread prediction models and their validation. Two methods commonly used to determine spread rate are the cumulative spread rate, calculated as the total distance travelled by a fire divided by the total time of travel, and the interval spread rate, calculated using the minimum time and maximum distance between observations. This paper analyses the differences between these two methods using experimental fires conducted in dry eucalypt forest leaf litter in either a combustion wind tunnel or large (4ha) field sites. Fires were ignited from a point, 400-mm and 800-mm line ignitions in the wind tunnel, and point and 120-m line ignitions in the field experiments. A total of 312 and 397 observations of distance travelled and time taken were made during the laboratory and field experiments respectively, along with associated environmental variables. Mean spread rates and standard deviations were significantly greater for the interval method than those of the cumulative method for all the laboratory data and the field point ignition fires, and the difference between them varied with distance and time since ignition. These findings have important implications for fire spread and acceleration model development.

Comparison of three methods to quantify the fire spread rate in laboratory experiments

2017 ◽  
Vol 26 (10) ◽  
pp. 877 ◽  
Author(s):  
J. S. Gould ◽  
A. L. Sullivan ◽  
R. Hurley ◽  
V. Koul
Keyword(s):  
Wind Tunnel ◽  
Laboratory Experiments ◽  
Visible Spectrum ◽  
Forest Litter ◽  
Fire Spread ◽  
Time Of Arrival ◽  
Spread Rate ◽  
Eucalypt Forest ◽  
Rate Of Spread ◽  
Selection Of

Different methods can be used to measure the time and distance of travel of a fire and thus its speed. The selection of a particular method will depend on the experimental objectives, design, scale, location (in the laboratory or field), required accuracy and resources available. In this study, measurements from ocular observation (directly by eye), visible spectrum video imagery and thermocouple instrumentation were used to compare their performance in quantifying the time of arrival and rate of spread of a fire burning across a eucalypt forest litter fuel bed in a combustion wind tunnel. All methods gave similar results, but there were some significant differences depending on the dryness of the fuel and speed of the wind.

Analysis of the uncertainty of fuel model parameters in wildland fire modelling of a boreal forest in north-east China

2019 ◽  
Vol 28 (3) ◽  
pp. 205 ◽  
Author(s):  
Longyan Cai ◽  
Hong S. He ◽  
Yu Liang ◽  
Zhiwei Wu ◽  
Chao Huang
Keyword(s):  
Monte Carlo ◽  
Wildland Fire ◽  
Time Lag ◽  
Fire Spread ◽  
Model Parameters ◽  
Spread Rate ◽  
North East ◽  
Fire Modelling ◽  
Fuel Model ◽  
Model Parameter Uncertainty

Fire propagation is inevitably affected by fuel-model parameters during wildfire simulations and the uncertainty of the fuel-model parameters makes forecasting accurate fire behaviour very difficult. In this study, three different methods (Morris screening, first-order analysis and the Monte Carlo method) were used to analyse the uncertainty of fuel-model parameters with FARSITE model. The results of the uncertainty analysis showed that only a few fuel-model parameters markedly influenced the uncertainty of the model outputs, and many of the fuel-model parameters had little or no effect. The fire-spread rate is the driving force behind the uncertainty of other fire behaviours. Thus, the highly uncertain fuel-model parameters associated with spread rate should be used cautiously in wildfire simulations. Monte Carlo results indicated that the relationship between model input and output was non-linear and neglecting fuel-model parameter uncertainty of the model would magnify fire behaviours. Additionally, fuel-model parameters have high input uncertainty. Therefore, fuel-model parameters must be calibrated against actual fires. The highly uncertain fuel-model parameters with high spatial-temporal variability consisted of fuel-bed depth, live-shrub loading and 1-h time-lag loading are preferentially chosen as parameters to calibrate several wildfires.

Current approaches to modelling the spread of wildland fire: a review

1998 ◽  
Vol 22 (2) ◽  
pp. 222-245 ◽  
Author(s):  
G. L.W. Perry
Keyword(s):  
Information Technologies ◽  
Spatial Information ◽  
Wildland Fire ◽  
Fire Risk ◽  
Fire Spread ◽  
Physical Models ◽  
Accurate Estimation ◽  
Fire Event ◽  
Fire Modelling ◽  
Modelling Techniques

This review considers the development of some of the models and modelling approaches designed to predict the spread and spatial behaviour of wildland fire events. Such events and their accurate prediction are of great importance to those seeking to understand and manage fire-prone ecosystems. The key problem which fire modelling seeks to address is outlined. Models predicting the rate of fire spread may be classified as physical, semi-physical or empirical according to the nature of their construction. The benefits and shortcomings of each type of model are considered with reference to specific examples of each type. It is shown that there are problems with current operational models which restrict their effective use. However, the development of rigorous physical models as replacements is impeded by conceptual and practical difficulties. Accurate estimation of the rate of spread and the intensity of a fire allows prediction of the final shape and area of a fire event. The modelling techniques used to estimate the shape and area of a fire are considered including the development of sophisticated computer-based simulations of fire spread. Spatial information technologies such as remote sensing and geographic information systems (GIS) offer great potential for the effective modelling of wildland fire behaviour. While such spatial information technologies have been frequently used in the evaluation of fire danger risk, their use for the simulation of the spatiotemporal behaviour of wildland fire is not common. The way in which spatial information technologies and decision-support systems are used for fire risk evaluation and fire spread simulation is discussed. Two research areas of great importance if fire modelling techniques are to improve are a better understanding of fire-dependent phenomena and the development of a ‘new generation’ of fire spread models; current trends in these areas of research are evaluated.

scholarly journals Resolving vorticity-driven lateral fire spread using the WRF-Fire coupled atmosphere-fire numerical model

2014 ◽  
Vol 2 (5) ◽  
pp. 3499-3531 ◽  
Author(s):  
C. C. Simpson ◽  
J. J. Sharples ◽  
J. P. Evans
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Wildland Fire ◽  
Fire Spread ◽  
Lateral Spread ◽  
Grid Spacing ◽  
Spread Rate ◽  
Model Framework ◽  
Fire Model ◽  
Horizontal Grid

Abstract. Fire channelling is a form of dynamic fire behaviour, during which a wildland fire spreads rapidly across a steep lee-facing slope in a direction transverse to the background winds, and is often accompanied by a downwind extension of the active flaming region and extreme pyro-convection. Recent work using the WRF-Fire coupled atmosphere-fire model has demonstrated that fire channelling can be characterised as vorticity-driven lateral fire spread (VDLS). In this study, 16 simulations are conducted using WRF-Fire to examine the sensitivity of resolving VDLS to spatial resolution and atmosphere-fire coupling within the WRF-Fire model framework. The horizontal grid spacing is varied between 25 and 90 m, and the two-way atmosphere-fire coupling is either enabled or disabled. At high spatial resolution, the atmosphere-fire coupling increases the peak uphill and lateral spread rate by a factor of up to 2.7 and 9.5. The enhancement of the uphill and lateral spread rate diminishes at coarser spatial resolution, and VDLS is not modelled for a horizontal grid spacing of 90 m. The laterally spreading fire fronts become the dominant contributors of the extreme pyro-convection. The resolved fire-induced vortices responsible for driving the lateral spread in the coupled simulations have non-zero vorticity along each unit vector direction, and develop due to an interaction between the background winds and vertical return circulations generated at the flank of the fire front as part of the pyro-convective updraft. The results presented in this study demonstrate that both high spatial resolution and two-way atmosphere-fire coupling are required to reproduce VDLS within the current WRF-Fire model framework.

Migration and fate of 14CH4 in subsoil: tracer experiments to inform model development

2012 ◽  
Vol 76 (8) ◽  
pp. 3345-3354 ◽  
Author(s):  
B. S. Atkinson ◽  
W. Meredith ◽  
C. Snape ◽  
M. Steven ◽  
A. R. Hoch ◽  
...  
Keyword(s):  
Field Experiments ◽  
Model Development ◽  
Laboratory Data ◽  
Isotope Ratio Mass Spectrometry ◽  
Undisturbed Soil ◽  
Oxidation Rates ◽  
Undisturbed Soils ◽  
The University ◽  
Tracer Experiments ◽  
Subsequent Incorporation

AbstractThe degree of transport and retention of 14CH4 in soil is being investigated in a series of laboratory experiments in preparation for field scale trials at the University of Nottingham. The experimental programme focusses on the behaviour and fate of 14CH4 injected into subsoil and its subsequent incorporation into vegetation under field conditions. Due to restrictions on the use of radioactive tracers in the field, 13CH4 is being used as a surrogate gas which can be handled conveniently in the laboratory and field and which can be measured with high precision using gas chromatography with isotope ratio mass spectrometry. The laboratory data indicate significant differences between the diffusion and oxidation rates of 13CH4 in re-packed and undisturbed soil columns, with both rates appearing to be significantly lower in undisturbed soils. Data from both laboratory and field experiments will be used to inform the development of a model of 14CH4 migration and its fate in the biosphere above a geological disposal facility.

A comparison of three approaches for simulating fine-scale surface winds in support of wildland fire management. Part I. Model formulation and comparison against measurements

2014 ◽  
Vol 23 (7) ◽  
pp. 969 ◽  
Author(s):  
Jason M. Forthofer ◽  
Bret W. Butler ◽  
Natalie S. Wagenbrenner
Keyword(s):  
Fire Management ◽  
Prediction Models ◽  
Wildland Fire ◽  
Surface Wind ◽  
Field Measurements ◽  
Fire Spread ◽  
Neutral Stability ◽  
Wind Fields ◽  
Forecast Models ◽  
Wildland Fire Management

For this study three types of wind models have been defined for simulating surface wind flow in support of wildland fire management: (1) a uniform wind field (typically acquired from coarse-resolution (~4km) weather service forecast models); (2) a newly developed mass-conserving model and (3) a newly developed mass and momentum-conserving model (referred to as the momentum-conserving model). The technical foundation for the two new modelling approaches is described, simulated surface wind fields are compared to field measurements, and the sensitivity of the new model types to mesh resolution and aspect ratio (second type only) is discussed. Both of the newly developed models assume neutral stability and are designed to be run by casual users on standard personal computers. Simulation times vary from a few seconds for the mass-conserving model to ~1h for the momentum-conserving model using consumer-grade computers. Applications for this technology include use in real-time fire spread prediction models to support fire management activities, mapping local wind fields to identify areas of concern for firefighter safety and exploring best-case weather scenarios to achieve prescribed fire objectives. Both models performed best on the upwind side and top of terrain features and had reduced accuracy on the lee side. The momentum-conserving model performed better than the mass-conserving model on the lee side.

scholarly journals A Deep Learning Approach to Downscale Geostationary Satellite Imagery for Decision Support in High Impact Wildfires

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 294
Author(s):  
Nicholas F. McCarthy ◽  
Ali Tohidi ◽  
Yawar Aziz ◽  
Matt Dennie ◽  
Mario Miguel Valero ◽  
...  
Keyword(s):  
Deep Learning ◽  
Decision Support ◽  
Real Time ◽  
Forest Fires ◽  
Wildland Fire ◽  
Fire Spread ◽  
Low Earth Orbit ◽  
Practical Implementation ◽  
Spatiotemporal Resolution ◽  
Active Fire

Scarcity in wildland fire progression data as well as considerable uncertainties in forecasts demand improved methods to monitor fire spread in real time. However, there exists at present no scalable solution to acquire consistent information about active forest fires that is both spatially and temporally explicit. To overcome this limitation, we propose a statistical downscaling scheme based on deep learning that leverages multi-source Remote Sensing (RS) data. Our system relies on a U-Net Convolutional Neural Network (CNN) to downscale Geostationary (GEO) satellite multispectral imagery and continuously monitor active fire progression with a spatial resolution similar to Low Earth Orbit (LEO) sensors. In order to achieve this, the model trains on LEO RS products, land use information, vegetation properties, and terrain data. The practical implementation has been optimized to use cloud compute clusters, software containers and multi-step parallel pipelines in order to facilitate real time operational deployment. The performance of the model was validated in five wildfires selected from among the most destructive that occurred in California in 2017 and 2018. These results demonstrate the effectiveness of the proposed methodology in monitoring fire progression with high spatiotemporal resolution, which can be instrumental for decision support during the first hours of wildfires that may quickly become large and dangerous. Additionally, the proposed methodology can be leveraged to collect detailed quantitative data about real-scale wildfire behaviour, thus supporting the development and validation of fire spread models.

Upward Fire Spread Rate Over Real-Scale EPS ETICS Façades

2021 ◽  
Author(s):  
Biao Zhou ◽  
Hideki Yoshioka ◽  
Takafumi Noguchi ◽  
Kai Wang ◽  
Xinyan Huang
Keyword(s):  
Fire Spread ◽  
Spread Rate ◽  
Real Scale

scholarly journals A Novel Approach for Operating Speed Continuous Predication Based on Alignment Space Comprehensive Index

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ying Yan ◽  
Gengping Li ◽  
Jinjun Tang ◽  
Zhongyin Guo
Keyword(s):  
Field Experiments ◽  
Prediction Models ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Driving Safety ◽  
Operating Speed ◽  
Passenger Cars ◽  
Comprehensive Index ◽  
Novel Approach ◽  
Lane Width

Operating speed is a critical indicator for road alignment consistency design and safety evaluation. Although extensive studies have been conducted on operating speed prediction, few models can finish practical continuous prediction at each point along alignment on multilane highways. This study proposes a novel method to estimate the operating speed for multilane highways in China from the aspect of the three-dimensional alignment combination. Operating speed data collected in field experiments on 304 different alignment combination sections are detected by means of Global Positioning System. First, the alignment comprehensive index (ACI) is designed and introduced to describe the function accounting for alignment continuity and driving safety. The variables used in ACI include horizontal curve radius, change rate of curvature, deflection angle of curve, grade, and lane width. Second, the influence range of front and rear alignment on speed is determined on the basis of drivers’ fixation range and dynamical properties of vehicles. Furthermore, a prediction model based on exponential relationships between road alignment and speeds is designed to predict the speed of passenger cars and trucks. Finally, three common criteria are utilized to evaluate the effectiveness of the prediction models. The results indicate that the prediction models outperform the other two operating speed models for their higher prediction accuracy.

Characterisation of the fuel and fire environment in southern Ontario’s tallgrass prairie

2015 ◽  
Vol 24 (8) ◽  
pp. 1118 ◽  
Author(s):  
Susan Kidnie ◽  
B. Mike Wotton
Keyword(s):  
Moisture Content ◽  
Tallgrass Prairie ◽  
Prescribed Burning ◽  
Fire Spread ◽  
Fuel Load ◽  
Prairie Restoration ◽  
Prescribed Burn ◽  
Spread Rate ◽  
Prescribed Burns ◽  
Tallgrass Prairie Restoration

Prescribed burning can be an integral part of tallgrass prairie restoration and management. Understanding fire behaviour in this fuel is critical to conducting safe and effective prescribed burns. Our goal was to quantify important physical characteristics of southern Ontario’s tallgrass fuel complex prior to and during prescribed burns and synthesise our findings into useful applications for the prescribed fire community. We found that the average fuel load in tallgrass communities was 0.70 kg m–2. Fuel loads varied from 0.38 to 0.96 kg m–2. Average heat of combustion did not vary by species and was 17 334 kJ kg–1. A moisture content model was developed for fully cured, matted field grass, which was found to successfully predict moisture content of the surface layers of cured tallgrass in spring. We observed 25 head fires in spring-season prescribed burns with spread rates ranging from 4 to 55 m min–1. Flame front residence time averaged 27 s, varying significantly with fuel load but not fire spread rate. A grassland spread rate model from Australia showed the closest agreement with observed spread rates. These results provide prescribed-burn practitioners in Ontario better information to plan and deliver successful burns.

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