Experiments on the influence of spot fire and topography interaction on fire rate of spread.

Spotting is thought to increase wildfire rate of spread (ROS) and in some cases become the main mechanism for spread. The role of spotting in wildfire spread is controlled by many factors including fire intensity, number of and distance between spot fires, weather, fuel characteristics and topograph...

Full description

Bibliographic Details
Main Authors: Michael Anthony Storey, Owen F Price, Miguel Almeida, Carlos Ribeiro, Ross A Bradstock, Jason J Sharples
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2021-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0245132
_version_ 1818348529141153792
author Michael Anthony Storey
Owen F Price
Miguel Almeida
Carlos Ribeiro
Ross A Bradstock
Jason J Sharples
author_facet Michael Anthony Storey
Owen F Price
Miguel Almeida
Carlos Ribeiro
Ross A Bradstock
Jason J Sharples
author_sort Michael Anthony Storey
collection DOAJ
description Spotting is thought to increase wildfire rate of spread (ROS) and in some cases become the main mechanism for spread. The role of spotting in wildfire spread is controlled by many factors including fire intensity, number of and distance between spot fires, weather, fuel characteristics and topography. Through a set of 30 laboratory fire experiments on a 3 m x 4 m fuel bed, subject to air flow, we explored the influence of manually ignited spot fires (0, 1 or 2), the presence or absence of a model hill and their interaction on combined fire ROS (i.e. ROS incorporating main fire and merged spot fires). During experiments conducted on a flat fuel bed, spot fires (whether 1 or 2) had only a small influence on combined ROS. Slowest combined ROS was recorded when a hill was present and no spot fires were ignited, because the fires crept very slowly downslope and downwind of the hill. This was up to, depending on measurement interval, 5 times slower than ROS in the flat fuel bed experiments. However, ignition of 1 or 2 spot fires (with hill present) greatly increased combined ROS to similar levels as those recorded in the flat fuel bed experiments (depending on spread interval). The effect was strongest on the head fire, where spot fires merged directly with the main fire, but significant increases in off-centre ROS were also detected. Our findings suggest that under certain topographic conditions, spot fires can allow a fire to overcome the low spread potential of downslopes. Current models may underestimate wildfire ROS and fire arrival time in hilly terrain if the influence of spot fires on ROS is not incorporated into predictions.
first_indexed 2024-12-13T17:51:30Z
format Article
id doaj.art-a4fdf0e2059a4a278d5300a3bdba6bb9
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-12-13T17:51:30Z
publishDate 2021-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-a4fdf0e2059a4a278d5300a3bdba6bb92022-12-21T23:36:30ZengPublic Library of Science (PLoS)PLoS ONE1932-62032021-01-01161e024513210.1371/journal.pone.0245132Experiments on the influence of spot fire and topography interaction on fire rate of spread.Michael Anthony StoreyOwen F PriceMiguel AlmeidaCarlos RibeiroRoss A BradstockJason J SharplesSpotting is thought to increase wildfire rate of spread (ROS) and in some cases become the main mechanism for spread. The role of spotting in wildfire spread is controlled by many factors including fire intensity, number of and distance between spot fires, weather, fuel characteristics and topography. Through a set of 30 laboratory fire experiments on a 3 m x 4 m fuel bed, subject to air flow, we explored the influence of manually ignited spot fires (0, 1 or 2), the presence or absence of a model hill and their interaction on combined fire ROS (i.e. ROS incorporating main fire and merged spot fires). During experiments conducted on a flat fuel bed, spot fires (whether 1 or 2) had only a small influence on combined ROS. Slowest combined ROS was recorded when a hill was present and no spot fires were ignited, because the fires crept very slowly downslope and downwind of the hill. This was up to, depending on measurement interval, 5 times slower than ROS in the flat fuel bed experiments. However, ignition of 1 or 2 spot fires (with hill present) greatly increased combined ROS to similar levels as those recorded in the flat fuel bed experiments (depending on spread interval). The effect was strongest on the head fire, where spot fires merged directly with the main fire, but significant increases in off-centre ROS were also detected. Our findings suggest that under certain topographic conditions, spot fires can allow a fire to overcome the low spread potential of downslopes. Current models may underestimate wildfire ROS and fire arrival time in hilly terrain if the influence of spot fires on ROS is not incorporated into predictions.https://doi.org/10.1371/journal.pone.0245132
spellingShingle Michael Anthony Storey
Owen F Price
Miguel Almeida
Carlos Ribeiro
Ross A Bradstock
Jason J Sharples
Experiments on the influence of spot fire and topography interaction on fire rate of spread.
PLoS ONE
title Experiments on the influence of spot fire and topography interaction on fire rate of spread.
title_full Experiments on the influence of spot fire and topography interaction on fire rate of spread.
title_fullStr Experiments on the influence of spot fire and topography interaction on fire rate of spread.
title_full_unstemmed Experiments on the influence of spot fire and topography interaction on fire rate of spread.
title_short Experiments on the influence of spot fire and topography interaction on fire rate of spread.
title_sort experiments on the influence of spot fire and topography interaction on fire rate of spread
url https://doi.org/10.1371/journal.pone.0245132
work_keys_str_mv AT michaelanthonystorey experimentsontheinfluenceofspotfireandtopographyinteractiononfirerateofspread
AT owenfprice experimentsontheinfluenceofspotfireandtopographyinteractiononfirerateofspread
AT miguelalmeida experimentsontheinfluenceofspotfireandtopographyinteractiononfirerateofspread
AT carlosribeiro experimentsontheinfluenceofspotfireandtopographyinteractiononfirerateofspread
AT rossabradstock experimentsontheinfluenceofspotfireandtopographyinteractiononfirerateofspread
AT jasonjsharples experimentsontheinfluenceofspotfireandtopographyinteractiononfirerateofspread