Ecology, meteorology and simulation of large wildland fires

Extreme-temperature events are known to favor large wildland fires and have consequences for human health and mortality, forest disturbance patterns, agricultural productivity, and the economic repercussions of these consequences combined. To gain insight into whether extreme-temperature events are changing in light of global climate dynamics, the annual numbers of high-temperature days (those with temperatures higher than 20, 22.5, and 25 ºC at 850 hPa) were analyzed across southern Europe from the years 1978 to 2012. A significant increase in the frequency of these days was found in many areas over the time period analyzed, and patterns in the spatial distribution of these changes were identified. Additionally, this work analyzes the effects of high temperature days on medium and large fires from 1978 to 2010 in Spain and other areas (Sardinia, Italy). A high temperature day was defined as being when air temperature at 850 hPa was higher than the 95th percentile of air temperature at that elevation from June to September across the study period. Temperature at 850 hPa was chosen because it properly characterizes the state of the lower troposphere. The effects of high temperature on forest fires were remarkable and significant in terms of fire number (15 % of total large fires occurred under high temperature days), burned area (25 % of the total burned area occurred under high temperature days). Fire size was also significantly higher under 95th percentile air temperature at 850 hPa and a large part of the largest fires in the past 20 years were under these extreme conditions. Additionally, both burned area and fire number only decreased under non-high temperature days in the study period and not under high temperature conditions. The worst consequence of wildland fires is the loss of human lives, a regular phenomenon over the last few decades worldwide. This work analyzes all recorded wildland fires in Spain with victims between 1980 and 2010. We classified causality causes during wildland fires to study the most frequent causes of fatalities and how they were related to regions, fire size, and extreme weather conditions (i.e., high temperature days). Trends in number of both injured and killed individuals were analyzed. We observed that the annual number of victims did not decrease in the study period. Entrapment is the most frequent cause of death within the fire suppression employees. Fire size is a key factor in the occurrence of victims because 95% of fatalities in wildland fires (not counting aerial casualties) happened in fires larger than 100 ha. High temperature days also were important because 60% of entrapments were produced in this kind of days.Los eventos con temperaturas extremas favorecen la ocurrencia de grandes incendios forestales y tienen consecuencias en la salud y mortalidad humana, los patrones de perturbación forestal, la productividad agrícola y las repercusiones económicas de estas consecuencias combinadas. Para conocer si los eventos de temperaturas extremas están cambiando bajo la dinámica de cambio global, se analizaron las cifras anuales de días de alta temperatura (aquellos con temperaturas superiores a los 20, 22,5 y 25 ºC a 850 hPa) en el sur de Europa en el periodo 1978-2012. Un aumento significativo en la frecuencia de este tipo de días se encontró en muchas áreas durante el período de tiempo analizado, y se identificaron patrones en la distribución espacial de estos cambios. Además, este trabajo analiza los efectos de días de alta temperatura en incendios forestales medianos y grandes en España desde 1978, así como en otras áreas (Cerdeña, Italia). Un día de alta temperatura se define cuando la temperatura del aire a 850 hPa es mayor que el percentil 95 de la temperatura del aire a 850 hPa de junio a septiembre en todo el período de estudio. Elegí la temperatura a 850 hPa porque caracteriza adecuadamente el estado de la baja troposfera. Los efectos de las altas temperaturas sobre los incendios forestales fueron notables y significativos en términos de número de incendios (el 15% del total de los grandes incendios ocurrieron bajo días de alta temperatura) y área quemada (25% del total de área quemada se produjo bajo días de alta temperatura). El tamaño de los incendios también fue significativamente mayor en condiciones de alta temperatura y gran parte de los incendios más grandes en los últimos 20 años fueron en este tipo de condiciones extremas. Además, tanto el número de incendios como el área quemada solamente disminuyeron bajo días de no alta temperatura en el período de estudio. La peor consecuencia de los incendios forestales es la pérdida de vidas humanas, un fenómeno que se ha producido con regularidad durante las últimas décadas en todo el mundo. Este trabajo analiza todos los incendios forestales en España con víctimas registradas entre 1980 y 2010. Los incendios se clasificaron por la causa que provocó la muerte de las víctimas durante los incendios forestales con el objetivo de estudiar las causas más frecuentes en accidentes mortales y cómo se relaciona con distintas regiones geográficas, el tamaño de los incendios, y las condiciones climáticas extremas (es decir, días de alta temperatura). Se analizaron tendencias temporales en el número de individuos heridos y muertos en el periodo de estudio. Se observa que el número anual de víctimas no disminuyó en el período de estudio. El atrapamiento es la causa más frecuente de muerte dentro de los empleados de extinción de incendios. El tamaño de los incendios es un factor clave en la aparición de las víctimas ya que el 95% de las muertes en incendios forestales (sin contar las bajas aéreas) ocurrió en incendios mayores de 100 ha. Los días de alta temperatura también fueron claves debido a que el 60% de atrapamientos se produjo en este tipo de días.Els esdeveniments amb temperatures extremes afavoreixen l’aparició de grans incendis forestals amb conseqüències en la salut i mortalitat humana, els patrons de pertorbació forestal, la productivitat agrícola i les repercussions econòmiques d’aquestes conseqüències combinades. Per conèixer si els esdeveniments de temperatures extremes estan canviant amb la dinàmica de canvi global, es van analitzar les xifres anuals de dies amb altes temperatures (aquells dies amb temperatures superiors als 20, 22.5 i 25ºC a 850hPa) al sud d’Europa en el període 1978-2012. Un augment significatiu en la freqüència d’aquest tipus de dies es va trobar en moltes àrees durant el període de temps analitzat, i es van identificar patrons en la distribució espacial d’aquests canvis. A més, aquest treball analitza els efectes de dies d’alta temperatura en incendis forestals mitjans i grans a Espanya des de 1978, així com en altres àrees (Cerdenya, Itàlia). Es defineix un dia d’alta temperatura quan la temperatura de l’aire a 850hPa és més gran que el percentil 95 de la temperatura de l’aire a 850hPa de juny a setembre en tot el període d’estudi. Vaig triar la temperatura a 850hPa perquè caracteritza adequadament l’estat de la baixa troposfera. Els efectes de les altes temperatures sobre els incendis forestals van ser notables i significatius en termes de nombre d’incendis (el 15% del total dels grans incendis es van produir en dies d’alta temperatura) i àrea cremada (el 25% del total d’àrea cremada es va produir en dies d’alta temperatura). Les dimensions dels incendis també van ser significativament més grans en condicions de temperatura i gran part dels incendis més grans en els últims 20 anys van ser en aquest tipus de condicions extremes. A més, tant el nombre d’incendis com l’àrea cremada només van disminuir en dies de no alta temperatura en el període d’estudi. La pitjor conseqüència dels incendis forestals és la pèrdua d’éssers humans, un fenomen que s’ha produït amb regularitat durant les últimes dècades a tot el món. Aquest treball analitza tots els incendis forestals d’Espanya amb víctimes registrades entre els anys 1980 i 2010. Els incendis es van classificar per la causa que va provocar la mort de les víctimes durant els incendis forestals amb l’objectiu d’estudiar les causes més freqüents en accidents mortals i la seva relació amb les diferents regions geogràfiques, les dimensions dels incendis, i les condicions climàtiques extremes (és a dir, dies d’alta temperatura). Es van analitzar tendències temporals en el nombre d’individus ferits i morts en el període d’estudi. L’atrapament és la causa més freqüent de mort dins dels empleats d’extinció d’incendis. Les dimensions dels incendis són un factor clau en l’aparició de les víctimes, ja que el 95% de les morts en incendis forestals (sense tenir en compte les baixes aèries) es van produir en incendis que afectaven més de 100 ha. Els dies d’alta temperatura també van ser claus pel fet que el 60% d’atrapaments es van produir en aquest tipus de dies

Fatalidades em incêndios florestais de 1945 a 2015 na Sardenha (Itália)

The worst outcome of wildland fires is the loss of human lives, a recurrent phenomenon over the last few decades in Sardinia, Europe and worldwide. This work analyzes all recorded fatalities in wildland fires in Sardinia from 1945 to 2015 and trends in terms of annual number of fatalities. This time period was split due to legal and socioeconomic changes periods (1945-1975; 1976-2000; 2001-2015). We classified accident types during wildland fires to study the most frequent causes of fatalities and how they were related 1) to involved human groups (professional firefighters, auxiliary firefighters, and civilians, 2) to fire size and 3) to extreme weather conditions. We observed that the annual number of victims was higher in the 1981-1999 period than in other periods with 2.6 fatalities per year. Entrapment is the most frequent cause of death within the fire professional firefighters (75.6 %). The rate of fatalities seemed to be higher in the 1981-1999 period for “civilians” and lower for “professional firefighters”. We detected that the annual number of “civilian” fatalities is higher in the 1981-1999 period with 1.6 fatalities per year. The calculated rate for “army forces & volunteer firefighters” group was in the middle ground. Entrapment is the most frequent cause of death with a percentage of 75.6 %. Fire size is a key factor in the fatality occurrence because over 80 % of deaths in wildland fires (without considering aerial accidents) happened in fires larger than 100 ha. Days with extreme weather conditions (high temperature or strong winds) were also instrumental because at least 47% of entrapments occurred in this kind of days.O pior resultado dos incêndios florestais é a perda de vidas humanas, um fenômeno recorrente ao longo das últimas décadas na Sardenha, Europa e em todo o mundo. Este trabalho analisa os registros de fatalidades em incêndios florestais na Sardenha, de 1945 até 2015 e tendências em termos de número anual de mortes. Este período de tempo foi dividido devido a alterações legais e sócioeconômicas (1945-1975; 1976-2000; 2001-2015). Nos classificados os tipos de acidente durante os incêndios florestais para estudar as causas mais frequentes de mortes e como elas se relacionados com 1) os grupos humanos (bombeiros profissionais, bombeiros auxiliares e civis), 2) ao tamanho do fogo e 3) condições meteorológicas extremas. Observamos que o número anual de vítimas foi maior no período de 1981-1999 do que em outros períodos, com 2,6 mortes por ano. Encurralamento pelo fogo é a causa mais frequente de morte de “bombeiros profissionais” (75,6%). A taxa de mortes parecia ser mais elevada no período 1981-1999 para “civis” e menor para “bombeiros profissionais”. Detectamos que o número anual de mortes de “civis” foi maior no período de 1981-1999, com 1,6 mortes por ano. A taxa calculada para o grupo “forças do exército e os bombeiros voluntários” foi no meio termo. Tamanho do fogo é um fator fundamental para a ocorrência de fatalidade, porque mais de 80% das mortes em incêndios florestais (sem considerar os acidentes aéreos) aconteceram em incêndios maiores que 100 ha. Dias com condições meteorológicas extremas (alta temperatura ou ventos fortes) também foram fundamentais, porque pelo menos 47% dos encurralamentos pelo fogo ocorreram nestes tipos de dias

Practitioner perceptions of wildland fire management across South Europe and Latin America

Wildfire presents a challenge to natural resource managers the world over, and the intentional setting of fires can be used to alleviate some of the challenges associated with wildfire management. Prescribed burning can be used prior to wildfires to reduce fuel loads and promote ecological integrity in fire-adapted systems, while suppression burning can help firefighters control the direction, extent, and intensity of wildfire behavior under extreme conditions. In both cases, the success of intentional fire use depends on training, knowledge, experience, and institutional and social support. The influence of these factors can significantly impact whether fire use is perceived as positive or negative, increasing or decreasing, and whether managers are supportive of its incorporation into their management planning and decision-making. Perceived impediments to fire use are likely to differ based on location, level of training and experience, and even the social context of fire management specific to different job positions in natural resource management. In order to explore how managers and stakeholders across the world perceive fire use, we surveyed over 700 respondents from 12 countries and three continents. This study represents the largest survey of perceptions on managed fire use ever conducted. Perceptions differed across age categories, job positions, and regions. Countries or regions with larger amounts of wildfire area burned tended to be more supportive of fire use for suppression, while countries with less wildfire had less positive perceptions of fire use for either prescribed or suppression burning. Bureaucracy and social perceptions were identified as impediments to using prescribed fire prior to wildfire occurrence, but neither were identified as impediments to fire use during suppression procedures. Across the countries, fire use in suppression was viewed more positively than prescribed fire use prior to wildfire occurrence.We are appreciative ForBurn project (Spanish Ministry of Economy and Competitiveness AGL2012-40098-C03-01)

Extreme temperature days and their potential impacts on southern Europe

Extreme-temperature events have consequences for human health and mortality, forest disturbance patterns, agricultural productivity, and the economic repercussions of these consequences combined. To gain insight into whether extreme-temperature events are changing in light of global climate dynamics, the annual numbers of high-temperature days (those with temperatures higher than 20, 22.5, and 25ºC at 850 hPa) were analyzed across southern Europe from the years 1978 to 2012. A significant increase in the frequency of these days was found in many areas over the time period analyzed, and patterns in the spatial distribution of these changes were identified.We discuss the potential consequences of the increases in high-temperature days with regards to forest fire risk, human health, agriculture, energy demands, and some potential economic repercussions

Fire effects in Pinus uncinata Ram. plantations

Aim of study: Understanding fire ecology of main forest species is essential for a sound, scientifically based on managing of wildlands and also to assess likely implications due to changes in fire regime under a global change scenario. Few references can be found about fire ecology of Pinus uncinata Ram. (PU). PU species grows in the Central Pyrenees where large, severe wildland fires did not occur frequently in the past. However, several fires with extreme fire behavior have affected PU stands in last years and they might disturb other PU forest in the future. Area of study: Cabdella fire (February 2012), in Lleida province, is one of the several wildland fires occurred in 2012 (winter season) in the Central Pyrenees. Fire affected a large PU plantation (102 ha) located at 1.800-2,100 meters above the sea. Material and methods: We have analyzed first order fire effects in three fireline intensity thresholds along three years in terms of mortality ratio, scorched height, percentage of scorched crown volume and bark char height. Main results: PU seems to be a very tolerant species to low and medium fire line intensity but fire effects were very significant when fire line intensity was high. In medium fireline intensity sites, probability of mortality ranged from 15 to 30% and the dead trees had the highest values on scorched height and percentage of scorched crown volume. Research highlights: Results from this work supports that prescribed burning might be used to efficiently decrease fuel load and fuel vertical continuity while avoiding considerable PU mortality. It also displayed that when fuel management has been implemented, PU mortality might be limited even under extreme fire behavior.ForBurn project (Spanish Ministry of Economy and Competitiveness AGL2012-40098-C03-01) and Pau Costa Foundation

Do climate teleconnections modulate wildfire-prone conditions over the Iberian Peninsula?

Climate teleconnections (CT) synchronize and influence weather features such as temperature, precipitation and, subsequently, drought and fuel moisture in many regions across the globe. CTs thus may be related to cycles in wildfire activity, and thereby help fire managers to anticipate fire-prone weather conditions as well as envisaging their future evolution. A wide number of CTs modulate weather in the Iberian Peninsula (IP), exerting different levels of influence at different spatial and seasonal scales on a wide range of weather factors. In this work, we investigated the link between the most relevant CT patterns in the IP and fire activity and danger, exploring different spatial and temporal scales of aggregation. We analyzed a period of 36 years (1980–2015) using historical records of fire events (>100 ha burned) and the Canadian Fire Weather Index (FWI). Cross-correlation analysis was performed on monthly time series of CTs and fire data. Results pointed towards the North Atlantic Oscillation (in the western half of the IP) and Mediterranean Oscillation Index (along the Mediterranean coast) as the key CTs boosting burned area (BA) and fire weather danger in the IP. Both CTs relate to the relative position of the Azorean anticlone, fostering hazardous fire weather conditions during their positive phases, i.e. low rainfall and warm temperature leading to low fuel moisture content. The Scandinavian pattern index also played an important role in the western half of the Peninsula, linked to a decrease in rainfall during its negative phases. Nonetheless, the association between the CTs and BA (up to 0.5 Pearson's R p < 0.05) was weaker than the observed between CTs and FWI (up to 0.75 Pearson's R p < 0.05).We would like to thank FCT (Fundação para a Ciência e a Tecnologia, Portugal) under project IMPECAF-PTDC/CTA-CLI/28902/2017, and project UIDB/50019/2020—IDL

Forest fire propagation prediction based on overlapping DDDAS forecasts

International Conference on Computational Science, ICCS 2015 – Computational Science at the Gates of NatureForest fire devastate every year thousand of hectares of forest around the world. Fire behavior prediction is a useful tool to aid coordination and management of human and mitigation resources when fighting against these kind of hazards. Any fire spread forecast system requires to be fitted with different kind of data with a high degree of uncertainty, such as for example, me- teorological data and vegetation map among others. The dynamics of this kind of phenomena requires to develop a forecast system with the ability to adapt to changing conditions. In this work two different fire spread forecast systems based on the Dynamic Data Driven Application paradigm are applied and an alternative approach based on the combination of both predictions is presented. This new method uses the computational power provided by high performance computing systems to deliver the predictions under strict real time constraints.This research has been supported by the Ministerio de Economía y Competitividad (MECSpain) under contract TIN2011-28689-C02-01 and the Catalan government under grant 2014- SGR-576