Lightning and lightning fire, central cordillera, Canada

2002 ◽  
Vol 11 (1) ◽  
pp. 41 ◽  
Author(s):  
Jack Wierzchowski ◽  
Mark Heathcott ◽  
Michael D. Flannigan
Keyword(s):  
British Columbia ◽  
Forest Fires ◽  
Fire Occurrence ◽  
Fire Weather Index ◽  
Lightning Strikes ◽  
Severity Rating ◽  
Continental Divide ◽  
Significant Difference ◽  
Lightning Discharges ◽  
Lightning Fire

This study examines the influences of fuel, weather and topography on lightning-caused forest fires in portions of southern British Columbia and Alberta, Canada. The results show a significant difference in lightning and lightning-caused fires east and west of the Continental Divide. In British Columbia, on average there was one fire for every 50 lightning discharges whereas in Alberta there was one fire for every 1400 lightning discharges. Elevation, the distribution of lightning strikes, the Daily Severity Rating (a component of the Canadian Forest Fire Weather Index System) and vegetation composition were identified as primary agents controlling lightning fire occurrence. However, the multivariate analysis does suggest that there are other factors influencing fire occurrence other than the biophysical factors we tested. The implications of the lightning and lightning-ignited fires for land managers are discussed.

Synoptic climatology of lightning-caused forest fires in subalpine and boreal forests

1996 ◽  
Vol 26 (10) ◽  
pp. 1859-1874 ◽  
Author(s):  
C.H. Nash ◽  
E.A. Johnson
Keyword(s):  
High Pressure ◽  
Forest Fires ◽  
Boreal Forests ◽  
Dry Weight ◽  
Weather Conditions ◽  
Synoptic Climatology ◽  
Fuel Moisture ◽  
Fire Occurrence ◽  
Lightning Strikes ◽  
Lightning Fire

The coupling of synoptic scale weather conditions with local scale weather and fuel conditions was examined for 2551 fires and 1 537 624 lightning strikes for the May through August fire seasons in 1988, 1989, 1992, and 1993 in Alberta and Saskatchewan. The probability of lightning fire occurrence (number of fires/number of strikes) is near zero until the Fine Fuel Moisture Code reaches 87 (moisture content of 14% dry weight), after which the probability increases rapidly. Duff Moisture and Drought Codes show less clear increases. In all cases, the probability of fire occurrence was low (the number of strikes greatly exceeded the number of forest fires), suggesting that lightning fire ignition coupled with early spread to detection was an uncommon event. This low probability of fire occurrence even at low fuel moisture may be a result of the arrangement and continuity of fuels in the boreal and subalpine forests. The literature suggests a higher probability of lightning-ignited fires in qualitatively different fuels, e.g., grasslands. The higher probability of fire at lower fuel moistures occurred primarily when high pressure dominated (positive 50-kPa anomaly) for at least 3 days and less than 1.5 mm precipitation occurred. The highest number of lightning strikes and largest number of fires also occurred when high pressure dominated. The high lightning numbers during high pressure systems were logistically related to increasing atmospheric instability (K-index).

Lightning-ignited forest fires in northwestern Ontario

1991 ◽  
Vol 21 (3) ◽  
pp. 277-287 ◽  
Author(s):  
M. D. Flannigan ◽  
B. M. Wotton
Keyword(s):  
Forest Fires ◽  
Spatial Scales ◽  
Daily Basis ◽  
Weather Index ◽  
Fire Weather Index ◽  
Northwestern Ontario ◽  
Northwestern Region ◽  
Lightning Discharges ◽  
Future Work ◽  
The Relationship

This study investigates the relationship between lightning activity and the occurrence of lightning-ignited forest fires in the Northwestern Region of Ontario. We found that the Duff Moisture Code (a component of the Fire Weather Index System) and the multiplicity of the negative lightning discharges were the most important variables for estimating the number of lightning-ignited fires on a daily basis for Universal Transverse Mercator zone15 in Ontario. Also, the results indicate that negative lightning ignited more fires than positive lightning discharges, which is contrary to popular belief. Nearly 50% of the variance in the forest fire occurrence data was explained using linear stepwise regression. Future work will focus on finer temporal and spatial scales.

scholarly journals Mesoscale spatiotemporal predictive models of daily human- and lightning-caused wildland fire occurrence in British Columbia

2020 ◽  
Vol 29 (1) ◽  
pp. 11
Author(s):  
Khurram Nadeem ◽  
S. W. Taylor ◽  
Douglas G. Woolford ◽  
C. B. Dean
Keyword(s):  
British Columbia ◽  
Wildland Fire ◽  
Characteristic Curve ◽  
Predictive Ability ◽  
Receiver Operator Characteristic Curve ◽  
Baseline Risk ◽  
Ranking Algorithm ◽  
Fire Occurrence ◽  
Selective Sampling ◽  
Lightning Fire

We developed three models of daily human- and lightning-caused fire occurrence to support fire management preparedness and detection planning in the province of British Columbia, Canada, using a lasso-logistic framework. Novel aspects of our work involve (1) using an ensemble of models that were created using 500 datasets balanced (through response-selective sampling) to have equal numbers of fire and non-fire observations; (2) the use of a new ranking algorithm to address the difficulty in interpreting variable importance in models with a large number of covariates. We also introduce the use of cause-specific average spatial daily fire occurrence, termed baseline risk, as a covariate for missing or poorly estimated factors that influence human and lightning fire occurrence. All three models have strong predictive ability, with areas under the Receiver Operator Characteristic curve exceeding 0.9.

A lightning fire occurrence model for Ontario

2005 ◽  
Vol 35 (6) ◽  
pp. 1389-1401 ◽  
Author(s):  
B M Wotton ◽  
David L Martell
Keyword(s):  
Forest Floor ◽  
Weather Conditions ◽  
Fire Spread ◽  
Positive Influence ◽  
Lightning Strike ◽  
Organic Layer ◽  
Fire Occurrence ◽  
Lightning Strikes ◽  
Cloud To Ground Lightning ◽  
Lightning Fire

Lightning strike, fire weather, and fire occurrence data were used to model (i) the probability that a lightning strike causes a sustainable ignition on the forest floor and (ii) the probability of an ignition being detected and reported to the fire management agency for each ecoregion in the province of Ontario. An index that tracks duff moisture content in very sheltered areas of a forest stand (near the tree boles) was the most significant predictor in each ignition model. The presence of positive cloud-to-ground lightning strikes was also found to have a significant and positive influence on the probability of ignition in most areas of the province with the exception of the far northwest. Weather conditions following a lightning storm influence the probability that a lightning strike causes a sustainable ignition. Models of the probability of detecting a fire ignited by lightning were also created for each of the ecoregions across Ontario. The form of these models varied somewhat among ecoregions, but contained an indicator of receptive surface fire spread conditions and an indicator of the dryness of the heavier fuels (the organic layer) in the forest floor.

scholarly journals The Role of Past Suicidal Behavior on Current Suicidality: A Retrospective Study in the Israeli Military

2021 ◽  
Vol 18 (2) ◽  
pp. 649
Author(s):  
Leah Shelef ◽  
Jessica M Rabbany ◽  
Peter M Gutierrez ◽  
Ron Kedem ◽  
Ariel Ben Yehuda ◽  
...  
Keyword(s):  
Suicide Attempt ◽  
Suicidal Behavior ◽  
Military Service ◽  
Suicide Ideation ◽  
Rating Scale ◽  
Suicide Attempts ◽  
Significant Risk ◽  
Significant Risk Factor ◽  
Severity Rating ◽  
Significant Difference

Past suicide attempts are a significant risk factor for future suicidality. Therefore, the present military-based study examined the past suicidal behavior of soldiers who recently made a severe suicide attempt. Our sample consisted of 65 active-duty soldiers (61.5% males), between the ages of 18 and 28 years old (M = 20.4, SD ± 1.3). The inclusion criterion was a recent severe suicide attempt, requiring at least a 24 h hospitalization. This sample was divided into two groups, according to previous suicidal behavior, namely whether their first suicide attempt was before or after enlistment (n = 25; 38.5% and n = 40; 61.5%, respectively). We then examined the lethality and intent of the recent event in regard to this division. Four measures were used to assess the subjects’ suicidal characteristics: the Columbia Suicide Severity Rating Scale, the Self-Harm Behavior Questionnaire, the Suicidal Behaviors Questionnaire-Revised, and the Beck Scale for Suicide Ideation. No significant difference in the severity of the suicide attempts (either actual or potential severity) were found between those who had suicide attempts before enlistment and those who had their first attempt in the service. As a matter of fact, most of the suicide attempts that occurred for the first time during military service had used a violent method (58.3%, n = 21). Finally, using multivariate analyses, we found that current thoughts and behavior, rather than past suicidality, was the strongest predictor for the lethality of suicide attempts.

scholarly journals Tendencies of Fire Development in the Forests of Ukraine

2020 ◽  
Vol 3 (1) ◽  
pp. 106
Author(s):  
Yevhen Melnyk ◽  
Vladimir Voron
Keyword(s):  
Forest Management ◽  
Forest Fires ◽  
Necessary Conditions ◽  
Climatic Conditions ◽  
Anthropogenic Factors ◽  
Burned Area ◽  
Fire Occurrence ◽  
Management Zones ◽  
Wildfire Occurrence ◽  
Management Zone

Preservation and increase of forest area are necessary conditions for the biosphere functioning. Forest ecosystems in most parts of the world are affected by fires. According to the latest data, the forest fire situation has become complicated in Ukraine, and this issue requires ongoing investigation. The aim of the study was to analyse the dynamics of wildfires in Ukrainian forests over recent decades and to assess the complex indicator of wildfire occurrence in various forest management zones and administrative regions. The average annual complex indicator of fire occurrence, in terms of wildfire number and burned area, was studied in detail in the forests of various administrative regions and forest management zones in Ukraine from 1998 to 2017. The results show that fire occurrence in both the number and area of fires can vary significantly in various forest management zones. There is a very noticeable difference in these indicators in some administrative regions within a particular forest management zone. The data show that the number of forest fires depends not only on the natural and climatic conditions of such regions, but also on anthropogenic factors.

scholarly journals Chromosome 22 Deletions and Suicidal Behavior in Schizophrenia

2021 ◽  
pp. 1-8
Author(s):  
Ali Bani-Fatemi ◽  
Christopher Adanty ◽  
Nasia Dai ◽  
Ariel Graff ◽  
Philip Gerretsen ◽  
...  
Keyword(s):  
Suicide Attempt ◽  
Suicidal Behavior ◽  
Copy Number ◽  
Rating Scale ◽  
Copy Number Variant ◽  
Chromosome 22 ◽  
Suicide Attempters ◽  
Severity Rating ◽  
Neuropsychiatric Diseases ◽  
Significant Difference

Background: Studies have shown that the overall copy number variant (CNV) load is associated with schizophrenia. Schizophrenia is a mental disorder that is frequently associated with suicidal behavior. Methods: We recruited 263 patients with schizophrenia from the Centre for Addiction and Mental Health. The Columbia Suicide Severity Rating Scale was used to assess the presence of lifetime suicide attempt. Genotyping was completed using the Illumina Omni 2.5 chip. We tested the association between deletion events on chromosome 22 with suicide attempt in our schizophrenia sample. Results: There was no significant difference between suicide attempters and non-attempters considering the presence/absence of deletion events on chromosome 22. Conclusion: Although our results did not show a significant association between deletions on chromosome 22 and suicide attempt in schizophrenia, CNV studies may reveal important, novel insights and open further investigation for the treatment of neuropsychiatric diseases.

COST-EFFECTIVENESS IMPACTS CANCER CARE FUNDING DECISIONS IN BRITISH COLUMBIA, CANADA, EVIDENCE FROM 1998 TO 2008

2017 ◽  
Vol 33 (4) ◽  
pp. 481-486
Author(s):  
Zahra Ismail ◽  
Stuart J. Peacock ◽  
Laurel Kovacic ◽  
Jeffrey S. Hoch
Keyword(s):  
British Columbia ◽  
Cost Effectiveness ◽  
Outcome Measures ◽  
Nonparametric Tests ◽  
Lower Probability ◽  
Economic Evidence ◽  
Cancer Drugs ◽  
Life Years ◽  
Significant Difference ◽  
The Mean

Objectives: The Priorities and Evaluation Committee (PEC) funding recommendations for new cancer drugs in British Columbia, Canada have been based on both clinical and economic evidence. The British Columbia Ministry of Health makes funding decisions. We assessed the association between cost-effectiveness of cancer drugs considered from 1998 to 2008 and the subsequent funding decisions.Methods: All proposals submitted to the PEC between 1998 and 2008 were reviewed, and the association between cost-effectiveness and funding decisions was examined by (i) using logistic regression to test the hypothesis that interventions with higher incremental cost-effectiveness ratios (ICERs) have a lower probability of receiving a positive funding decision and (ii) using parametric and nonparametric tests to determine if a statistically significant difference exists between the mean cost-effectiveness of funded versus not funded proposals. A sub-analysis was conducted to determine if the findings varied across different outcome measures.Results: Of the 149 proposals reviewed, 78 reported cost-effectiveness using various outcome measures. In the proposals that used life-years gained as the outcome (n = 22), a statistically significant difference of nearly $115,000 was observed between the mean ICERs for funded proposals ($42,006) and for unfunded proposals ($156,967). An odds ratio indicating higher ICERs have a lower probability of being funded was also found to be statistically significant (p < .05).Conclusions: Economic evidence appears to play a role in British Columbia cancer funding decisions from 1998 to 2008; other decision-making criteria may also have an important role in recommendations and subsequent funding decisions.

scholarly journals Temporal variations and change in forest fire danger in Europe for 1960–2012

2014 ◽  
Vol 14 (6) ◽  
pp. 1477-1490 ◽  
Author(s):  
A. Venäläinen ◽  
N. Korhonen ◽  
O. Hyvärinen ◽  
N. Koutsias ◽  
F. Xystrakis ◽  
...  
Keyword(s):  
Forest Fire ◽  
Forest Fires ◽  
National Level ◽  
Temporal Variations ◽  
Fire Danger ◽  
Fire Season ◽  
Fire Weather ◽  
Fire Weather Index ◽  
Current Season ◽  
Forest Fire Danger

Abstract. Understanding how fire weather danger indices changed in the past and how such changes affected forest fire activity is important in a changing climate. We used the Canadian Fire Weather Index (FWI), calculated from two reanalysis data sets, ERA-40 and ERA Interim, to examine the temporal variation of forest fire danger in Europe in 1960–2012. Additionally, we used national forest fire statistics from Greece, Spain and Finland to examine the relationship between fire danger and fires. There is no obvious trend in fire danger for the time period covered by ERA-40 (1960–1999), whereas for the period 1980–2012 covered by ERA Interim, the mean FWI shows an increasing trend for southern and eastern Europe which is significant at the 99% confidence level. The cross correlations calculated at the national level in Greece, Spain and Finland between total area burned and mean FWI of the current season is of the order of 0.6, demonstrating the extent to which the current fire-season weather can explain forest fires. To summarize, fire risk is multifaceted, and while climate is a major determinant, other factors can contribute to it, either positively or negatively.

Sign in / Sign up

Export Citation Format

Share Document