scholarly journals Evaluating the Ability of FARSITE to Simulate Wildfires Influenced by Extreme, Downslope Winds in Santa Barbara, California

Fire ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 29 ◽  
Author(s):  
Katelyn Zigner ◽  
Leila M. V. Carvalho ◽  
Seth Peterson ◽  
Francis Fujioka ◽  
Gert-Jan Duine ◽  
...  
Keyword(s):  
Fire Spread ◽  
Strong Wind ◽  
Santa Barbara ◽  
Spread Model ◽  
Sensitivity Tests ◽  
Wildfire Spread ◽  
Fire Area ◽  
Strong Winds ◽  
Wind Events ◽  
In Fire

Extreme, downslope mountain winds often generate dangerous wildfire conditions. We used the wildfire spread model Fire Area Simulator (FARSITE) to simulate two wildfires influenced by strong wind events in Santa Barbara, CA. High spatial-resolution imagery for fuel maps and hourly wind downscaled to 100 m were used as model inputs, and sensitivity tests were performed to evaluate the effects of ignition timing and location on fire spread. Additionally, burn area rasters from FARSITE simulations were compared to minimum travel time rasters from FlamMap simulations, a wildfire model similar to FARSITE that holds environmental variables constant. Utilization of two case studies during strong winds revealed that FARSITE was able to successfully reconstruct the spread rate and size of wildfires when spotting was minimal. However, in situations when spotting was an important factor in rapid downslope wildfire spread, both FARSITE and FlamMap were unable to simulate realistic fire perimeters. We show that this is due to inherent limitations in the models themselves, related to the slope-orientation relative to the simulated fire spread, and the dependence of ember launch and land locations. This finding has widespread implications, given the role of spotting in fire progression during extreme wind events.

scholarly journals Modelling long-term fire regimes of southern California shrublands

2011 ◽  
Vol 20 (1) ◽  
pp. 1 ◽  
Author(s):  
Seth H. Peterson ◽  
Max A. Moritz ◽  
Marco E. Morais ◽  
Philip E. Dennison ◽  
Jean M. Carlson
Keyword(s):  
Southern California ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Spread ◽  
Computationally Efficient ◽  
Interval Maps ◽  
Spread Model ◽  
Wind Events ◽  
In Fire

This paper explores the environmental factors that drive the southern California chaparral fire regime. Specifically, we examined the response of three fire regime metrics (fire size distributions, fire return interval maps, cumulative total area burned) to variations in the number of ignitions, the spatial pattern of ignitions, the number of Santa Ana wind events, and live fuel moisture, using the HFire fire spread model. HFire is computationally efficient and capable of simulating the spatiotemporal progression of individual fires on a landscape and aggregating results for fully resolved individual fires over hundreds or thousands of years to predict long-term fire regimes. A quantitative understanding of the long-term drivers of a fire regime is of use in fire management and policy.

scholarly journals A methodology to conduct wind damage field surveys for high-impact weather events of convective origin

2020 ◽  
Vol 20 (5) ◽  
pp. 1513-1531 ◽  
Author(s):  
Oriol Rodríguez ◽  
Joan Bech ◽  
Juan de Dios Soriano ◽  
Delia Gutiérrez ◽  
Salvador Castán
Keyword(s):  
Field Studies ◽  
High Impact ◽  
Strong Wind ◽  
Field Surveys ◽  
Weather Events ◽  
Straight Line ◽  
High Impact Weather ◽  
Strong Winds ◽  
Wind Events ◽  
The One

Abstract. Post-event damage assessments are of paramount importance to document the effects of high-impact weather-related events such as floods or strong wind events. Moreover, evaluating the damage and characterizing its extent and intensity can be essential for further analysis such as completing a diagnostic meteorological case study. This paper presents a methodology to perform field surveys of damage caused by strong winds of convective origin (i.e. tornado, downburst and straight-line winds). It is based on previous studies and also on 136 field studies performed by the authors in Spain between 2004 and 2018. The methodology includes the collection of pictures and records of damage to human-made structures and on vegetation during the in situ visit to the affected area, as well as of available automatic weather station data, witness reports and images of the phenomenon, such as funnel cloud pictures, taken by casual observers. To synthesize the gathered data, three final deliverables are proposed: (i) a standardized text report of the analysed event, (ii) a table consisting of detailed geolocated information about each damage point and other relevant data and (iii) a map or a KML (Keyhole Markup Language) file containing the previous information ready for graphical display and further analysis. This methodology has been applied by the authors in the past, sometimes only a few hours after the event occurrence and, on many occasions, when the type of convective phenomenon was uncertain. In those uncertain cases, the information resulting from this methodology contributed effectively to discern the phenomenon type thanks to the damage pattern analysis, particularly if no witness reports were available. The application of methodologies such as the one presented here is necessary in order to build homogeneous and robust databases of severe weather cases and high-impact weather events.

Statistical Summary and Case Studies of Strong Wind Damage in China

2013 ◽  
Vol 8 (6) ◽  
pp. 1096-1102 ◽  
Author(s):  
Shuyang Cao ◽  
◽  
Jin Wang ◽  
Keyword(s):  
Case Studies ◽  
Low Cost ◽  
Wind Damage ◽  
Strong Wind ◽  
Severe Damage ◽  
Engineering Measures ◽  
Strong Winds ◽  
Wind Events ◽  
Forestry Products ◽  
Statistical Summary

Strong wind events, such as typhoons and tornados, have caused severe damage to buildings and other structures as well as agricultural and forestry products in China. This paper analyzes statistical data on typhoons and tornados in China, and it reports case studies on strong wind damage. Lessons from past damage from strong winds, as well as engineering measures against potential wind damage to low-cost houses, are presented for the purpose of wind-related disaster risk reduction.

scholarly journals Calibration of FARSITE fire area simulator in Iranian northern forests

2014 ◽  
Vol 2 (9) ◽  
pp. 6201-6240 ◽  
Author(s):  
R. Jahdi ◽  
M. Salis ◽  
A. A. Darvishsefat ◽  
F. J. Alcasena Urdiroz ◽  
V. Etemad ◽  
...  
Keyword(s):  
Vegetation Type ◽  
Fire Spread ◽  
Physical Models ◽  
Northern Iran ◽  
Burned Areas ◽  
Risk Monitoring ◽  
Spread Model ◽  
Fuel Models ◽  
And Behavior ◽  
In Fire

Abstract. Wildfire simulators based on empirical or physical models need to be locally calibrated and validated when used under conditions that differ from those where the simulators were originally developed. This study aims to calibrate FARSITE fire spread model considering a set of recent wildfires occurred in Northern Iran forests. Site specific fuel models in the study areas were selected by sampling the main natural vegetation type complexes and assigning standard fuel models. Overall, simulated fires presented reliable outputs that accurately replicated the observed fire perimeters and behavior. Standard fuel models of Scott and Burgan (2005) afforded better accuracy in the simulated fire perimeters than the standard fuel models of Anderson (1982). The best match between observed and modeled burned areas was observed on herbaceous type fuel models. Fire modeling showed a high potential for estimating spatial variability in fire spread and behavior in the study areas. This work represents a first step in the application of fire spread modeling on Northern Iran for wildfire risk monitoring and management.

Climatology of High Wind Events in the Owens Valley, California

2008 ◽  
Vol 136 (9) ◽  
pp. 3536-3552 ◽  
Author(s):  
Shiyuan Zhong ◽  
Ju Li ◽  
C. David Whiteman ◽  
Xindi Bian ◽  
Wenqing Yao
Keyword(s):  
Sierra Nevada ◽  
Blow Up ◽  
Common Belief ◽  
Strong Wind ◽  
High Wind ◽  
Owens Valley ◽  
Reanalysis Dataset ◽  
Strong Winds ◽  
Wind Events ◽  
Upper Level

Abstract The climatology of high wind events in the Owens Valley, California, a deep valley located just east of the southern Sierra Nevada, is described using data from six automated weather stations distributed along the valley axis in combination with the North American Regional Reanalysis dataset. Potential mechanisms for the development of strong winds in the valley are examined. Contrary to the common belief that strong winds in the Owens Valley are westerly downslope windstorms that develop on the eastern slope of the Sierra Nevada, strong westerly winds are rare in the valley. Instead, strong winds are highly bidirectional, blowing either up (northward) or down (southward) the valley axis. High wind events are most frequent in spring and early fall and they occur more often during daytime than during nighttime, with a peak frequency in the afternoon. Unlike thermally driven valley winds that blow up valley during daytime and down valley during nighttime, strong winds may blow in either direction regardless of the time of the day. The southerly up-valley winds appear most often in the afternoon, a time when there is a weak minimum of northerly down-valley winds, indicating that strong wind events are modulated by local along-valley thermal forcing. Several mechanisms, including downward momentum transfer, forced channeling, and pressure-driven channeling all play a role in the development of southerly high wind events. These events are typically accompanied by strong south-southwesterly synoptic winds ahead of an upper-level trough off the California coast. The northerly high wind events, which typically occur when winds aloft are from the northwest ahead of an approaching upper-level ridge, are predominantly caused by the passage of a cold front when fast-moving cold air behind the surface front undercuts and displaces the warmer air in the valley. Forced channeling by the sidewalls of the relatively narrow valley aligns the wind direction with the valley axis and enhances the wind speeds.

Trees and their response to wind: mid Flandrian strong winds, Severn Estuary and inner Bristol Channel, southwest Britain

1992 ◽  
Vol 338 (1286) ◽  
pp. 335-364 ◽  
Keyword(s):  
Field Studies ◽  
Acute Angle ◽  
Strong Wind ◽  
Early Maturity ◽  
General Direction ◽  
Severn Estuary ◽  
Constant Variance ◽  
Strong Winds ◽  
Wind Events ◽  
Fall Direction

The response of contemporary trees to strong winds (gale force and greater) is repeatable and well defined, as shown by field studies in south east Britain after the October 1987 and January 1990 events, combined with awide-ranging literature survey. It involves the general processes of windprune, windsnap, windtilt and windthrow. Windprune depends on a range of physical and physiological mechanisms and leads to the loss of axial symmetry by a tree, especially where open-grown at an exposed site. Windsnap, windtilt and windthrow see the fall of a tree, as the result of either the breaking of the trunk or partial to full uprooting. Damage of this sort in a forest or woodland ranges from single trees, to scattered groups (swathes), to general devastation. In the main, perfectly healthy trees in youth or early maturity are affected by windsnap, windtilt and windthrow during strong wind events. Their fall-direction is readily established using the position of the rootball or snapped end of the trunk, the alignment of a broken trunk and stump, the taper of the trunk, the position on the trunk of relatively crowded branches (tree crown), and the position of the typically upward acute angle between branch and trunk. Contemporary trees overthrown by wind fall in a direction close to the wind. The variance of fall-directions in a sample due to a single wind event is observed to increase with the size of the woodland area from which the sample is drawn, but appears to become constant for sample areas in excess of 10 2 - 10 3 ha. Because this constant variance is relatively small, the mean fall-direction becomes, in contemporary woodlands and forests, a trustworthy indicator of the general direction of the strong wind which felled the trees. Rooted peats of mid Flandrian age ( ca . 6000-2500 conventional radiocarbon years) which include prostrate trees are widely present among the post-glacial estuarine silts exposed along the shores of the Severn Estuary and the inner Bristol Channel. The trees when overthrown appear in the main to have been perfectly healthy and in youth to early maturity. Oak and alder are the predominant species, and their fall-directions, as judged from the criteria listed from contemporary forests and woodlands, and measured at 18 horizons distributed over 14 sites, are highly coherent both locally and over the area as a whole. Using a model in which the variance of fall-directions observed for a single event is combined with a probability density for event mean directions, it appears that the trees fossilized in the peats were felled by strong winds which blew chiefly toward a range of directions from N.N.W . clockwise to S.S.E. A westerly zonal air-flow is indicated but, compared to the contemns than now, with a greater emphasis on both southerly and westerly to northwesterly blows.

scholarly journals Response of an Antarctic Peninsula Fjord to Summer Katabatic Wind Events

2019 ◽  
Vol 49 (6) ◽  
pp. 1485-1502 ◽  
Author(s):  
Øyvind Lundesgaard ◽  
Brian Powell ◽  
Mark Merrifield ◽  
Lisa Hahn-Woernle ◽  
Peter Winsor
Keyword(s):  
Antarctic Peninsula ◽  
Upper Ocean ◽  
Katabatic Wind ◽  
Strong Wind ◽  
Deep Basin ◽  
Wind Event ◽  
Salinity Increase ◽  
Strong Winds ◽  
Wind Events ◽  
Passive Tracers

AbstractFjords along the western Antarctic Peninsula are episodically exposed to strong winds flowing down marine-terminating glaciers and out over the ocean. These wind events could potentially be an important mechanism for the ventilation of fjord waters. A strong wind event was observed in Andvord Bay in December 2015, and was associated with significant increases in upper-ocean salinity. We examine the dynamical impacts of such wind events during the ice-free summer season using a numerical model. Passive tracers are used to identify water mass pathways and quantify exchange with the outer ocean. Upwelling and outflow in the model fjord generate an average salinity increase of 0.3 in the upper ocean during the event, similar to observations from Andvord Bay. Down-fjord wind events are a highly efficient mechanism for flushing out the upper fjord waters, but have little net impact on deep waters in the inner fjord. As such, summer episodic wind events likely have a large effect on fjord phytoplankton dynamics and export of glacially modified upper waters, but are an unlikely mechanism for the replenishment of deep basin waters and oceanic heat transport toward inner-fjord glaciers.

Using a statistical model of past wildfire spread to quantify and map the likelihood of fire reaching assets and prioritise fuel treatments

2020 ◽  
Vol 29 (5) ◽  
pp. 401 ◽  
Author(s):  
Owen F. Price ◽  
Michael Bedward
Keyword(s):  
Fire Spread ◽  
R Package ◽  
Wildland Urban Interface ◽  
Ignition Probability ◽  
Spread Model ◽  
Eastern Australia ◽  
Asset Location ◽  
Wildfire Spread ◽  
Fire Spreading

We present a method to quantify and map the probability of fires reaching the vicinity of assets in a wildfire-prone region, by extending a statistical fire spread model developed on historical fire patterns in the Sydney region, Australia. It calculates the mean probability of fire spreading along sample lines around assets, weights the probability according to ignition probability and also estimates the change in spread probability that fuel reduction in treatment blocks would achieve. We have developed an R package WildfireRisk to implement the analysis and demonstrate it with two case studies in forested eastern Australia. The probability of a fire reaching the vicinity of an asset was highest in the heavily forested parts of each case study, but when weighted for ignition probability, the high probability shifted to the wildland–urban interface. Further, when weighted by asset location, high-priority areas for treatment were in blocks next to the wildland–urban interface. This method is objective, fast and based on the behaviour of real historical fires. We recommend its use in wildfire risk planning, as an adjunct to heuristic methods and simulations. Additional functionality can be incorporated into our method, for instance via a function for building impact.

scholarly journals Atmospheric circulation patterns associated with strong wind events in Catalonia

2011 ◽  
Vol 11 (1) ◽  
pp. 145-155 ◽  
Author(s):  
J. C. Peña ◽  
M. Aran ◽  
J. Cunillera ◽  
J. Amaro
Keyword(s):  
Principal Component ◽  
Strong Wind ◽  
Atmospheric Circulation Patterns ◽  
Synoptic Weather ◽  
Weather Events ◽  
Circulation Patterns ◽  
Discriminant Analyses ◽  
High Impact Weather ◽  
Strong Winds ◽  
Wind Events

Abstract. The benefit of having a daily synoptic weather type catalogue and even more, a detailed catalogue for high impact weather events is well recognised by both climatologist and meteorologist communities. In this way the Meteorological Service of Catalonia (SMC) has produced some accurate classifications for extreme events, such as hailstorms or strong winds (SW). Within the framework of the MEDEX project, the SMC has been collaborating to increase the level of awareness about these events. Following this line of work, the aim of this study is to characterise the SW events in Catalonia. According to the guidelines of the MEDEX project we worked with its SW event database for the period June 1995 to May 2004. We also used the period 2005–2009 to test the methodology. The methodology is based on principal component, cluster and discriminant analyses and applied to four variables: SLP, temperature at 850 hPa and geopotential at 500 hPa on a synoptic-scale and local gust wind. We worked with ERA-Interim reanalysis and applied discriminant analysis to test the quality of the methodology and to classify the events of the validation period. We found seven patterns for the SW events. The strongest event corresponds to NW-Flow with the Azores Anticyclone and the passing of a low pressure through the Pyrenees. This methodology has distinguished the summer events in an independent cluster. The results obtained encourage us to follow this line of work.

scholarly journals FIRE BEHAVIOR PREDICTING MODELS EFFICIENCY IN BRAZILIAN COMMERCIAL EUCALYPT PLANTATIONS

CERNE ◽  
2016 ◽  
Vol 22 (4) ◽  
pp. 389-396 ◽  
Author(s):  
Benjamin Leonardo Alves White ◽  
Larissa Alves Secundo White ◽  
Genésio Tâmara Ribeiro ◽  
Rosemeri Melo Souza
Keyword(s):  
Fire Suppression ◽  
Fire Behavior ◽  
Fire Spread ◽  
Flame Length ◽  
Eucalypt Plantations ◽  
Spread Model ◽  
Experimental Laboratory ◽  
Predicted Values ◽  
In Fire ◽  
Better Than

ABSTRACT Knowing how a wildfire will behave is extremely important in order to assist in fire suppression and prevention operations. Since the 1940’s mathematical models to estimate how the fire will behave have been developed worldwide, however, none of them, until now, had their efficiency tested in Brazilian commercial eucalypt plantations nor in other vegetation types in the country. This study aims to verify the accuracy of the Rothermel (1972) fire spread model, the Byram (1959) flame length model, and the fire spread and length equations derived from the McArthur (1962) control burn meters. To meet these objectives, 105 experimental laboratory fires were done and their results compared with the predicted values from the models tested. The Rothermel and Byram models predicted better than McArthur’s, nevertheless, all of them underestimated the fire behavior aspects evaluated and were statistically different from the experimental data.

Sign in / Sign up

Export Citation Format

Share Document