Graduation Date
Summer 2025
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources, option Forestry, Watershed, & Wildland Sciences
Committee Chair Name
David Greene
Committee Chair Affiliation
Cal Poly Humboldt Faculty or Staff
Second Committee Member Name
Jeffrey Kane
Second Committee Member Affiliation
Cal Poly Humboldt Faculty or Staff
Third Committee Member Name
Sara McAllister
Third Committee Member Affiliation
Community Member or Outside Professional
Fourth Committee Member Name
Jason Forthofer
Fourth Committee Member Affiliation
Community Member or Outside Professional
Keywords
Wildfire, California, Fire Investigation, Cigarette Ignition, Ignition, Grass Ignition, Fire Pattern Indicators
Abstract
As wildfires in North America increase in size and frequency, the societal impacts become greater as well. With greater risk and high fire suppression costs it is pertinent to improve fire investigation methods and limit the potential for human caused ignitions. Two distinct studies were carried out to assess the accuracy of fire pattern indicators and the efficacy of “fire safe” cigarette technology in lowland grass fuel types in California. The first study utilized 24 experimental small-scale fires within a wind tunnel to examine the accuracy of microscale fire pattern indicators and the factors that influence the accuracy of predictions in wildfire origin investigations. An analysis of variance was used to detect differences in angular accuracy of various fire pattern indicators and logistic regression was used to determine how wind speed, flame spread type (heading, flanking, and backing), and ignition affect origin predictions at different levels of angular accuracy. All fire pattern indicators examined displayed an accuracy at or better than the currently accepted ± 90° margin of error. Out of the fire pattern indicators examined grass stemfall tended to be the least accurate with the highest variability. At the ± 90° resolution flame spread and windspeed had the largest affect on successful predictions, as the resolution was made finer (< ± 90°) ignition type and indicator category had a greater impact on success. The second study compared the rates of self-extinguishment of “fire safe” cigarettes using industry standard testing compared to conditions that are exposed to wind and dried grassy fuels. Logistic regression was used to model the probability of self-extinguishment in various combinations of wind and substrate. Cigarettes that passed standardized tests failed when grassland conditions were mimicked. Both wind and exposure to dried grasses reduced the rate of self-extinguishment, with the combination of both leading to a rate of self-extinguishment well below the rate required to be certified as “fire safe”. These results provide an indication that current cigarette safety standards do not wholistically reduce ignition propensity in all substrates.
Citation Style
APA
Recommended Citation
Haltermann, Trevor Blackwell, "From spark to wildfire: predicting wildfire origins and the efficacy of “fire safe” cigarettes in California grasslands" (2025). Cal Poly Humboldt theses and projects. 2328.
https://digitalcommons.humboldt.edu/etd/2328