scholarly journals The relationship of large fire occurrence with drought and fire danger indices in the western USA, 1984–2008: the role of temporal scale

2013 ◽  
Vol 22 (7) ◽  
pp. 894 ◽  
Author(s):  
Karin L. Riley ◽  
John T. Abatzoglou ◽  
Isaac C. Grenfell ◽  
Anna E. Klene ◽  
Faith Ann Heinsch
Keyword(s):  
Primary Objective ◽  
Fire Danger ◽  
Drought Severity ◽  
Monthly Precipitation ◽  
Fire Occurrence ◽  
Large Fire ◽  
Short Term ◽  
Area Burned ◽  
Standardised Precipitation Index ◽  
The Relationship

The relationship between large fire occurrence and drought has important implications for fire prediction under current and future climates. This study’s primary objective was to evaluate correlations between drought and fire-danger-rating indices representing short- and long-term drought, to determine which had the strongest relationships with large fire occurrence at the scale of the western United States during the years 1984–2008. We combined 4–8-km gridded drought and fire-danger-rating indices with information on fires greater than 404.7ha (1000acres). To account for differences in indices across climate and vegetation assemblages, indices were converted to percentile conditions for each pixel. Correlations between area burned and short-term indices Energy Release Component and monthly precipitation percentile were strong (R2=0.92 and 0.89), as were correlations between number of fires and these indices (R2=0.94 and 0.93). As the period of time tabulated by indices lengthened, correlations with fire occurrence weakened: Palmer Drought Severity Index and 24-month Standardised Precipitation Index percentile showed weak correlations with area burned (R2=0.25 and –0.01) and number of large fires (R2=0.3 and 0.01). These results indicate associations between short-term indices and moisture content of dead fuels, the primary carriers of surface fire.

Statistical Model for Forecasting Monthly Large Wildfire Events in Western United States

2007 ◽  
Vol 46 (7) ◽  
pp. 1020-1030 ◽  
Author(s):  
Haiganoush K. Preisler ◽  
Anthony L. Westerling
Keyword(s):  
United States ◽  
Statistical Model ◽  
Spatial Scales ◽  
Severity Index ◽  
Fire Danger ◽  
Western United States ◽  
Drought Severity ◽  
Large Fire ◽  
Confidence Bounds ◽  
Regression Techniques

Abstract The ability to forecast the number and location of large wildfire events (with specified confidence bounds) is important to fire managers attempting to allocate and distribute suppression efforts during severe fire seasons. This paper describes the development of a statistical model for assessing the forecasting skills of fire-danger predictors and producing 1-month-ahead wildfire-danger probabilities in the western United States. The method is based on logistic regression techniques with spline functions to accommodate nonlinear relationships between fire-danger predictors and probability of large fire events. Estimates were based on 25 yr of historic fire occurrence data (1980–2004). The model using the predictors monthly average temperature, and lagged Palmer drought severity index demonstrated significant improvement in forecasting skill over historic frequencies (persistence forecasts) of large fire events. The statistical models were particularly amenable to model evaluation and production of probability-based fire-danger maps with prespecified precisions. For example, during the 25 yr of the study for the month of July, an area greater than 400 ha burned in 3% of locations where the model forecast was low; 11% of locations where the forecast was moderate; and 76% of locations where the forecast was extreme. The statistical techniques may be used to assess the skill of forecast fire-danger indices developed at other temporal or spatial scales.

scholarly journals Assessment of Forest Fire Rating Systems in Typical Mediterranean Forest, Crete, Greece

2017 ◽  
Author(s):  
Mohamed Elhag ◽  
Slivena Boteva
Keyword(s):  
Moisture Content ◽  
Forest Fire ◽  
Pinus Halepensis ◽  
Water Status ◽  
Fire Danger ◽  
Forest Understory ◽  
Fire Season ◽  
Fire Occurrence ◽  
Fire Weather Index ◽  
Area Burned

Abstract. The Fire Weather Index (FWI) module was tested under the Mediterranean- type conditions of Crete (Greece) for the two fire seasons 2008–2009. High correlations were found between the Fine Fuel Moisture Code (FFMC) and the Duff Moisture Code (DMC. The Drought Code (DC) was insignificantly correlated with the soil moisture content. No significant correlation was found between the area burned by wildfires and any component of the FWI system during the studied period, unlike fire occurrence with which most of the components were highly correlated. Meanwhile, the Keetch-Byram Drought Index (KBDI) of the American Forest Fire Danger Rating System (NFFDRS) was also examined under the same conditions. It provided a useful means of monitoring general wetting and drying cycles, but is inadequate for indicating daily fire danger throughout the fire season in our region. Weak correlations between the KBDI- the fire occurrence and the area burned were found for the two fire seasons studied-2008–2009. Correlations between the KBDI and litter, duff and soil did not give statistically sound results. On the contrary, the KBDI seemed to predict with high accuracy the moisture content of three annual plants (Piplatherum miliaceum, Parietaria diffusa, Avena sterillis) with a shallow rooting system of Pinus halepensis forest understory in the region. This indicated that the index was adequate, to a certain extent, to represent the upper soil layers' water status, while it is unsuitable to predict needles moisture content of Pinus halepensis, which has a deep rooting system.

scholarly journals Large California wildfires: 2020 fires in historical context

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Jon E. Keeley ◽  
Alexandra D. Syphard
Keyword(s):  
Palmer Drought Severity Index ◽  
Historical Context ◽  
Severity Index ◽  
First Century ◽  
Drought Severity ◽  
Large Fire ◽  
Early Twenty ◽  
Large Fires ◽  
Relationship Of ◽  
The Relationship

Abstract Background California in the year 2020 experienced a record breaking number of large fires. Here, we place this and other recent years in a historical context by examining records of large fire events in the state back to 1860. Since drought is commonly associated with large fire events, we investigated the relationship of large fire events to droughts over this 160 years period. Results This study shows that extreme fire events such as seen in 2020 are not unknown historically, and what stands out as distinctly new is the increased number of large fires (defined here as > 10,000 ha) in the last couple years, most prominently in 2020. Nevertheless, there have been other periods with even greater numbers of large fires, e.g., 1929 had the second greatest number of large fires. In fact, the 1920’s decade stands out as one with many large fires. Conclusions In the last decade, there have been several years with exceptionally large fires. Earlier records show fires of similar size in the nineteenth and early twentieth century. Lengthy droughts, as measured by the Palmer Drought Severity Index (PDSI), were associated with the peaks in large fires in both the 1920s and the early twenty-first century.

Factors influencing wildfire occurrence and distribution in eastern Kentucky, USA

2007 ◽  
Vol 16 (1) ◽  
pp. 23 ◽  
Author(s):  
John K. Maingi ◽  
Mary C. Henry
Keyword(s):  
Human Factors ◽  
Palmer Drought Severity Index ◽  
Severity Index ◽  
Thematic Mapper ◽  
Drought Severity ◽  
Fire Occurrence ◽  
Eastern Kentucky ◽  
Unemployment Rates ◽  
Area Burned ◽  
Drought Severity Index

Most wildfires in Kentucky occur in the heavily forested Appalachian counties in the eastern portion of the state. In the present study, we reconstructed a brief fire history of eastern Kentucky using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus images acquired between 1985 and 2002. We then examined relationships between fire occurrence and area burned, and abiotic and human factors. Abiotic factors included Palmer Drought Severity Index, slope, aspect, and elevation, and human factors included county unemployment rates, distance to roads, and distance to populated places. Approximately 83% of the total burned area burned only once, 14% twice, and 3% thrice. More fires burned in the winter compared with the fall, but the latter fires were larger on average and accounted for ~71% of the total area burned. Fire size was negatively correlated with Palmer Drought Severity Index for certain times of the year. There were significant relationships between elevation and slope and fire occurrence, but not between aspect and fire occurrence. We found links between fire location and proximity to roads and settlements, but we found no correlations between monthly unemployment rates and arson-caused fires.

Characterising vegetation fuel moisture conditions from microwave satellite observations for fire danger prediction at continental to global scales

2020 ◽  
Author(s):  
Matthias Forkel ◽  
Niels Andela ◽  
Wouter A. Dorigo ◽  
Markus Drüke ◽  
Sandy P. Harrison ◽  
...  
Keyword(s):  
Satellite Observations ◽  
Fire Danger ◽  
Fuel Moisture ◽  
Fire Occurrence ◽  
Fire Dynamics ◽  
Radiative Power ◽  
Moisture Conditions ◽  
Fuel Moisture Content ◽  
The Relationship ◽  
Fire Radiative Power

<p>Spatial patterns and temporal changes in live fuel moisture content (LFMC) have been intensively estimated from satellite observations in the optical domain of the electromagnetic spectrum. Such estimates are valuable to predict regional to local variations in fire danger (Yebra et al., 2018). However, optical satellite measurements saturate fast in dense canopies and are generally hampered during cloud cover. Microwave satellite observations can penetrate clouds and the canopy (dependent on the wavelength) and hence have been intensively used to derive surface soil moisture (SSM) or vegetation optical depth (VOD), which is a proxy for vegetation water content (Moesinger et al., 2019). However, the relationship of microwave VOD to LFMC and the predictive capabilities of VOD for fire dynamics have not yet been investigated at large scales. Here we aim to assess how VOD reflects changes in LFMC and the sensitivity of VOD to different properties of fire dynamics such as fire occurrence, size, burned area, and fire radiative power.</p><p>We compared VOD in different microwave bands (Ku-, X-, and C-band) from the VODCA dataset (Moesinger et al., 2019) with LFMC from MODIS retrievals (Yebra et al., 2018). Our results demonstrate that VOD and LFMC are moderately to highly correlated but the strength and shape of the relationship depends on land cover type. In a preliminary analysis, we then predicted the probability of fire occurrence (Andela et al., 2019) and fire radiative power (Kaiser et al., 2012) from VOD, SSM, and climate data using the random forest machine learning approach. The initial results show that VOD is a skilful predictor for continental-scale fire dynamics. Furthermore, our results suggest that the combination of LFMC from optical satellites with microwave SSM and VOD might allow to comprehensively estimate ecosystem fuel moisture conditions. Hence microwave satellite observations will be valuable for the development of integrated fire danger prediction systems.</p><p> </p><p><strong>References</strong></p><p>Andela, N., Morton, D.C., Giglio, L., Paugam, R., Chen, Y., Hantson, S., Werf, G.R. van der, Randerson, J.T., 2019. The Global Fire Atlas of individual fire size, duration, speed and direction. Earth Syst. Sci. Data 11, 529–552. https://doi.org/10.5194/essd-11-529-2019</p><p>Kaiser, J.W., Heil, A., Andreae, M.O., Benedetti, A., Chubarova, N., Jones, L., Morcrette, J.-J., Razinger, M., Schultz, M.G., Suttie, M., van der Werf, G.R., 2012. Biomass burning emissions estimated with a global fire assimilation system based on observed fire radiative power. Biogeosciences 9, 527–554. https://doi.org/10.5194/bg-9-527-2012</p><p>Moesinger, L., Dorigo, W., Jeu, R. de, Schalie, R. van der, Scanlon, T., Teubner, I., Forkel, M., 2019. The Global Long-term Microwave Vegetation Optical Depth Climate Archive VODCA. Earth Syst. Sci. Data Discuss. 1–26. https://doi.org/10.5194/essd-2019-42</p><p>Yebra, M., Quan, X., Riaño, D., Rozas Larraondo, P., van Dijk, A.I.J.M., Cary, G.J., 2018. A fuel moisture content and flammability monitoring methodology for continental Australia based on optical remote sensing. Remote Sens. Environ. 212, 260–272. https://doi.org/10.1016/j.rse.2018.04.053</p>

Near-term probabilistic forecast of significant wildfire events for the Western United States

2016 ◽  
Vol 25 (11) ◽  
pp. 1169 ◽  
Author(s):  
Haiganoush K. Preisler ◽  
Karin L. Riley ◽  
Crystal S. Stonesifer ◽  
Dave E. Calkin ◽  
W. Matthew Jolly
Keyword(s):  
United States ◽  
Risk Index ◽  
Decision Support Tool ◽  
The United States ◽  
Fire Danger ◽  
Fire Occurrence ◽  
Large Fire ◽  
Support Tool ◽  
Large Fires ◽  
Fire Danger Indices

Fire danger and potential for large fires in the United States (US) is currently indicated via several forecasted qualitative indices. However, landscape-level quantitative forecasts of the probability of a large fire are currently lacking. In this study, we present a framework for forecasting large fire occurrence – an extreme value event – and evaluating measures of uncertainties that do not rely on distributional assumptions. The statistical model presented here incorporates qualitative fire danger indices along with other location and seasonal specific explanatory variables to produce maps of forecasted probability of an ignition becoming a large fire, as well as numbers of large fires with measures of uncertainties. As an example, 6 years of fire occurrence data from the Western US were used to study the utility of two fire danger indices: the 7-Day Significant Fire Potential Outlook issued by Predictive Services in the US and the National Fire Danger Rating’s Energy Release Component. This exercise highlights the potential utility of the quantitative risk index as a real-time decision support tool that can enhance managers’ abilities to discriminate among planning areas in terms of the likelihood and range of expected significant fire events. The approach is applicable wherever there are archived historical data from both observed fires and fire danger indices.

Evaluation of the Efficacy of ST2 and NT-proBNP in the Diagnosis and Prediction of Short- Term Prognosis in Heart Failure with Reduced Ejection Fraction

2017 ◽  
Vol 9 (04) ◽  
Author(s):  
Shivananda B Nayak ◽  
Dharindra Sawh ◽  
Brandon Scott ◽  
Vestra Sears ◽  
Kareshma Seebalack ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Cardiac Biomarkers ◽  
Double Blind Study ◽  
Short Term ◽  
Double Blind ◽  
Reduced Ejection Fraction ◽  
The Mean ◽  
Design And Methods ◽  
The Relationship

Purpose: i) To determine the relationship between the cardiac biomarkers ST2 and NT-proBNP with ejection fraction (EF) in heart failure (HF) patients. ii) Assess whether a superiority existed between the aforementioned cardiac markers in diagnosing the HF with reduced EF. iii) Determine the efficacy of both biomarkers in predicting a 30-day cardiovascular event and rehospitalization in patients with HF with reduced EF iv) To assess the influence of age, gender, BMI, anaemia and renal failure on the ST2 and NT-proBNP levels. Design and Methods: A prospective double-blind study was conducted to obtain data from a sample of 64 cardiology patients. A blood sample was collected to test for ST2 and NT-proBNP. An echocardiogram (to obtain EF value), electrocardiogram and questionnaire were also obtained. Results: Of the 64 patients enrolled, 59.4% of the population had an EF less than 40%. At the end of the 30- day period, 7 patients were warded, 37 were not warded, one died and 17 were non respondent. Both biomarkers were efficacious at diagnosing HF with a reduced EF. However, neither of them were efficacious in predicting 30-day rehospitalization. The mean NT-proBNP values being: not rehospitalized (2114.7486) and 30 day rehospitalization (1008.42860) and the mean ST2 values being: not rehospitalized (336.1975), and 30-day rehospitalization. (281.9657). Conclusion: Neither ST2 or NT-proBNP was efficacious in predicting the short- term prognosis in HF with reduced EF. Both however were successful at confirming the diagnosis of HF in HF patients with reduced EF.

Plebiscitary Politics and the Threats to Legality

2019 ◽  
pp. 275-289
Author(s):  
Claudius Härpfer
Keyword(s):  
The State ◽  
Short Term ◽  
Political Processes ◽  
The Face ◽  
State Of Affairs ◽  
The Relationship

In recent times we find many plebiscitary acts that seek to democratically legitimize political processes in any direction. They have in common that they interrupt the normal routine of representative democracies to a certain degree and create an extra-daily state of affairs, which entails not only direct but also indirect consequences. The text attempts to systematize some of these mechanisms from a Weberian perspective using Brexit as an example. After a brief overview of Weber’s short-term politically inspired statements on plebiscitary democracy, the text systematizes Weber’s understanding of the state as a bureaucratic apparatus that requires any kind of leader to be controlled. Subsequently, the text discusses the relationship between domination, legality, and rationality in order to finally point out the danger of erosion of truth and legality through the emergence of competing consensus communities in the face of competing conceptions of order.

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