Réf. R: ALP-FFIRS 2012 - R

Référence bibliographique complète
ALP FFIRS 2012. Forest fires in the Alps Prediction, Prediction, knowledge and cooperation to protect our forest heritage. Final booklet of the Alpine Space project ALP FFIRS ("ALPine Forest Fire WaRning System"), BIANCHI, E. (Ed.), December 2012, 52 pp., ISBN 978-88-7479-119-4. [Rapport en ligne]

Mots-clés
 

Organismes / Contact
Partenaires

©2012, Arpa Piemonte
Via Pio VII, 9
10135 Turin (I)

Editing and publishing coordination: Elisa Bianchi - Arpa Piemonte - Regional Agency for Environmental Protection of Piedmont, Institutional Communication

Publication made under the Alpine Space Programme - European Territorial Cooperation 2007-2013 (www.alpine-space.eu), cofinanced by the European Regional Development Fund, ALP FFIRS (ALPine Forest Fire WaRning System, www.alpffirs.eu)

 

Authors
Simona Barbarino - Arpa Piemonte, Regional Agency for Environmental Protection of Piedmont
Alexander Beck - ZAMG
Paolo Camerano - Institute for Wood Plants and the Environment
Daniele Cane - Arpa Piemonte, Regional Agency for Environmental Protection of Piedmont
Giampaolo Cocca - ERSAF Lombardy
Bruna Comini - ERSAF Lombardy
Marco Conedera - WSL
Elena della Valentina - Piedmont Region
Nadia Di Narda - Autonomous Region of Friuli Venezia Giulia
Matteo Giovannozzi - Institute for Wood Plants and the Environment
Anze Japelj - Slovenian Forestry Institute
Lado Kutnar - Slovenian Forestry Institute
Adrien Mangiavillano - CEREN
Annette Menzel - Technical University of Munich
Federico Pelfini - Piedmont Region
Renata Pelosini - Arpa Piemonte, Regional Agency for Environmental Protection of Piedmont
Graziella Priod - Arpa Piemonte, Regional Agency for Environmental Protection of Piedmont
Luisa Renier - Institute for Wood Plants and the Environment
Christian Schunk - Technical University of Munich
Harald Vacik - University of Natural Resources and Applied Life Sciences, Vienna
Eva Valese - University of Padua - Department of Land and Agroforestry Systems
Clemens Wastl - Technical University of Munich

Principaux rapports scientifiques sur lesquels s'est appuyé le rapport
 

(1) - Paramètre(s) atmosphérique(s) modifié(s)
(2) - Elément(s) du milieu impacté(s)
(3) - Type(s) d'aléa impacté(s)
(3) - Sous-type(s) d'aléa
Temperature, Precipitation Vegetation Forest fire  

Pays / Zone
Massif / Secteur
Site(s) d'étude
Exposition
Altitude
Période(s) d'observation
Large part of the Alpine arc in Italy, Switzerland, Austria, France, Germany and Slovenia          

(1) - Modifications des paramètres atmosphériques
Reconstitutions
 
Observations

Climate change in the Alps (...)

Since the beginning of the twentieth century, temperatures have globally increased. The IPCC report of 2007 reported an increase of about 0.7°C in the average global temperature over the last hundred years. More detailed analysis of the Alpine area, show an increase of about 1 °C over the last 50 years, more pronounced in winter and an increase in the variability of summer temperature (especially the last 20 years).

Modélisations

Several general circulation models predict an amplification of this trend, with increases up to 0.8 - 3.5°C by 2100, depending on the scenario of socio-economic development assumed, to which a given content of greenhouse gas emissions into the atmosphere is associated (IPCC, 2007).
A significant increase in temperature is expected in mountainous regions such as the Alps, as a result of response mechanisms (melting glaciers, decreased snow cover and albedo modification, etc.).
A simulation of changes in temperature and precipitation up to the middle of the twenty-first century was conducted using the COSMO-CLM regional climate model. While temperatures seem to increase in a wide area of the Alps (by approximately 0.6-1.5 °C), the change in the spatial distribution of precipitation is more complex, with a general decrease south of the Alps and a slight increase in northern and western Alps.

Hypothèses
 

Informations complémentaires (données utilisées, méthode, scénarios, etc.)
 

(2) - Effets du changement climatique sur le milieu naturel
Reconstitutions
 
Observations

Alpine forests
Forests are the second most important type of land cover and they characterize the landscape. Forests cover about 40% of the Alps and their extension is increasing. This is mainly due to man abandonment of mountain settlements. (...)

What are the forest’s functions?
Alpine forests perform different functions that are crucial for socio-economic development, especially for the social welfare of the Alpine region, as well as for Alpine forests regions that are farther afield. Timber has been making a comeback as a material used in construction and as a source of renewable energy. Woody biomass is in fact one of the pillars underpinning energy sustainability.
Closely related to wood production is the carbon storage: the alpine forests “store” considerable quantities of this molecule thus contributing positively to the carbon cycle and the reduction of the greenhouse effect.
The protective function carried out by forests, with respect to human settlements and communication routes, is estimated in terms of monetary value at more than 10 billion euro. In addition, approximately one-fifth of all forests have a function of land preservation providing protection from fl oods, landslides, mudslides and avalanches. (...)

The alpine vegetation
The distribution and type of alpine vegetation are the result of a combination of anthropogenic and climate factors (such as rainfall, temperature, sun exposure, snow cover, etc..) and other factors related to the former such as altitude, slope, morphology and the type of soil.

With regard to climate, the following factors should be considered:
• climate types range from oceanic to continental, from the boreal type to the sub-Mediterranean type;
• along the southern limit the Alpine chain is reached by strong Mediterranean influence, on the eastern part it is influenced by continental climate;
• depending on the morphology and width of the mountain chain the continental sectors vary in size or are sometimes absent.

The territory can be divided according to the following horizontal axes (horizons) and bioclimatic districts:
• esalpic or prealpine characterized by more abundant rainfall and milder temperatures,
• mesalpic, transitional,
• endalpic or intra-alpine characterized by continental climate (scarce precipitation and pronounced annual temperature range).

The vegetation of the Alps is the result of the mix of about 40 tree species, of which 30% are coniferous and 70% are broadleaf.

13% Subalpine larch, arolla pine and dwarf pine forests
13% Chestnut forests
_4% Minor forests
25% Other forests
12% Subalpine and mountainous spruce forests and mountainous mixed spruce and silver fir forests
11% Other thermophilous deciduous forests
_8% Reforestation
14% Mountainous beech forests of Central Europe and Illyria

[Fig. 5]: Distribution of the different categories or groups of categories, according to the classifi cation of European Forest Types (European forest type), 2006

Mountainous beech forests of Central Europe and Illyria: mountainous beech forest is the typical vegetation of the mesalpic sectors of the Alps. It consists of beech forests sometimes with Abies alba and Picea abies, depending on the ecological conditions. These forests are located at altitudes between 900 and 1800 m a.s.l., on different kinds of soil ranging from acidic to basic. In most cases these are pure beech forests due to human intervention that removed conifers. In all cases the grass cover is quite limited, sometimes absent, as is the shrub cover. The thick litter (accumulation of dead leaves on the ground) that is typically found in beech forest may be a cause of ground fires. In these cases the fire advances very slowly, but can be very serious because it damages the plants’ root system and it is hard to suppress.

Chestnut forests: these are the most extended forests in the Alpine area. They are anthropogenic forests where chestnut trees (Castanea sativa) have replaced the Quercus pubescens, Quercus petraea and Fagus sylvatica. In the past they were mostly fruit crops, today they are coppices pure in species composition or mixed with broadleaf trees, pioneer or exotic species such as Robinia pseudoacacia. This species has a high capacity of regrowth that offsets its very thin bark which makes it easily damaged by fires. Not unlike beech forests, also in chestnut forests the fl ame spreading is related to the thick litter, where insidious ground fires may develop, sometimes affecting also the lower part of the crown.

Subalpine larch, arolla pine and dwarf pine forests: they are the most extended coniferous forests in the Alps (Figure 8). They are characterized by the presence of Larix decidua, Pinus cembra, Pinus uncinata (western part of the Alps), Pinus mugo (Eastern and south-western part of the Alps), Picea abies and Abies alba. There are three different forest types depending on their localization. In the endalpic districts (Valle d’Aosta, Vallese, Engadina, Val Venosta, etc.) and at the higher altitudes of mesalpic districts, there are the sub- Alpine forests, pure or mixed with Pinus cembra, Larix decidua, Pinus uncinata and Pinus mugo.

Subalpine and mountainous spruce forests and mountainous mixed spruce and silver fir forests: in the mountain area there are forests of Picea abies, and mixed forests of Picea abies and Abies alba. In the eastern Alps there are forests of Pinus sylvestris and Pinus nigra. They are woods growing on poor soils, locally mixed with Quercus pubescens and pioneer broadleaf trees. Like all conifers, these species are prone to crown fires. This kind of fire is very destructive but fires at high altitudes are not frequent. Some species have special adaptations to fire, Larix decidua for example has a thick bark as a defence against fire, others like Pinus nigra are stimulated to germination after fire.

Other thermophilous deciduous forests: these are sub-mountainous and mountainous forests with a predominance of oaks such as Quercus pubescens and Quercus cerris, also with Fraxinus Ornus and Ostrya carpinifolia. Within this category, on the Alpine area, there are four forest types. Quercus pubescens forests are mainly localized in the dryer valleys or on the rugged and southern slopes of the mountains. Usually they are low fertility woods with the frequent presence of other species such as Pinus sylvestris, Fraxinus Ornus, Ostrya carpinifolia (east of the Alps), as well as the Buxus sempervirens. Due to their southern exposure, these forests are characterized by a thick groundcover of grasses that is frequently the cause of fire ignition. Both Quercus pubescens and Quercus cerris trees have a thick bark, which helps them defend against fire as well as a good capacity of regrowth after the fire. In this category, especially in the eastern Alps, there are significant forests of Ostrya carpinifolia, Fraxinus Ornus, Carpinus orientalis, Quercus cerris, Pinus nigra.

Reforestation: this category consists of artifi cial woods of coniferous or broadleaf trees, including site-native species and not site-native-species. The most widespread species are Picea abies, Pinus nigra, Pseudotsuga douglasii, Robinia pseudoacacia etc. In the past, reforestation mostly involved only one species which resulted in loss of biodiversity. Due to their similar age they are at risk of collapse and are very sensitive to various natural factors such as winds, heavy snow, diseases and fires. Where conifers are the prevalent species crown fires often develop not least due to the combustion of the resin. These fires are very destructive. Among the remaining categories, some of them are described below:

Sub-mountainous beech forests of Central Europe: these beech forests are characterized by a mix of beech trees with species such as Quercus pubescens, Ostrya carpinifolia and Fraxinus Ornus. On acid soils, beech is associated with Quercus Petrea and Tilia. Fires develop in a manner similar to that described for mountainous beech forests.

Mid-boreal coniferous forest and mixed coniferous and broadleaf forests: these forests are composed mainly by Pinus sylvestris, mixed with birches. This category has a small extension on the Alpine Space and it is not frequently subject to fires.

Acidophilus oakwood and oak-birch forest: this category, typical of acid soils, includes two types of forests, the acidophilus oakwood mainly composed by Quercus petraea and those mixed with birches. These forests are frequently associated with other broadleaf pioneer species (Populus tremula, Salix caprea etc.), Pinus sylvestris in the warmer districts, and Fraxinus excelsior and maples in the northern rainy side of the Alps. These forests are characterized by the presence of a dense undergrowth of blueberries or graminoids that are easily flammable. The Quercus petraea has a thick bark that protects it from fire and shows good post-fire renewal due to its ability to produce new shoots from the base of the tree; conversely, birches, owing to their very thin bark, are very vulnerable to fire and frequently do not survive it.

Mixed mesophytic broadleaf forests: this category includes mixed forests of Quercus petraea, Quercus robur, Carpinus betulus, Fraxinus excelsior and Fraxinus angustifolia, Acer campestre, Acer pseudoplatanus, Acer platanoides and Tilia cordata. Within this category different types can be identified. The most common type is the ash forests grown on abandoned crops. Ash forests are localized all along the Alpine chain, with two main concentration zones in the south-western and south-eastern part of it. Depending on the altitude, ash trees can be mixed with Acer pseudoplatanus, Prunus avium, Quercus petraea, Acer campestre, Taxus baccata, Ilex aquifolium, birch, elm, alder, rowan. In the rainy districts there are mixed forests of Quercus petraea and Tilia cordata, with Fagus sylvatica, Taxus baccata and Ilex aquifolium. In watersheds, ravines and slopes with large blocks of debris, Quercus petraea is replaced by Acer pseudoplatanus, Acer platanoides and Tilia cordata. In both cases, there is a welldeveloped undergrowth of grasses and shrubs. Site conditions are characterized by high humidity which make this category not very prone to forest fires.

Thermophilous evergreen broadleaf forests: these forests are dominated by the Quercus ilex. They occupy small areas of the southern part of the Alps, such as the Marittime Alps, and the Prealps in Veneto and Friuli. They are mixed forests with Ostrya carpinifolia, Fraxinus Ornus, Quercus pubescens, Carpinus orientalis etc. The Quercus ilex, being a species that originates from environments subject to frequent fires, has developed a good resistance to fire, thanks to its thick bark and good regenerative capacity.

Mediterranean coniferous forests: as the previous category, these forests are rather sporadic in the Alps, being limited to small patches of Pinus Pinea, Pinus pinaster, sometimes mixed with Pinus nigra. These species, which are frequently affected by crown fires, are the ones best adapted to fire. They have a bark resistant to fire and have developed sophisticated seed release and germination induction mechanisms triggered by the heat.

Pioneer forests differently composed: this is a heterogeneous category composed by pioneers or invasive species such as Alnus viridis, Populus tremula, birch, goldenchain, rowan, etc... These forests grow in places with different ecological conditions, generally characterized by a thick undergrowth of grasses that favors the onset of fire.

Shrubs: this category includes wooded plants with a prevalence of shrubs which generally occupy abandoned crops or forest limits, on arid soils. They usually include the following species: Prunus spp, Amelanchier ovalis, Juniperus communis and nana, Genista spp. etc... Due to their highly fl ammable biomass, these shrubs are often subject to considerably large fires that are frequently originated by grazing management practices..

Modélisations

 

Hypothèses

Europe
11 million hectares of forests in Europe are affected by various types of damage caused by fire, weather conditions such as wind and snow, insects and diseases, wild and farm animals. The damage from weather is mainly found in the Eastern-Central Europe, Western-Central Europe, Northern and South-west Europe. The damage due to fire is greater in the Russian region and in the South-East and South-West Europe. Recent studies have highlighted that the impact of climate change and other global changes on forests will increase. Research in this field suggests that the dangers to which forests are exposed, such as forest fires, caused by more frequent extreme climate events may increase considerably in the future.


Sensibilité du milieu à des paramètres climatiques
Informations complémentaires (données utilisées, méthode, scénarios, etc.)
 

 


(3) - Effets du changement climatique sur l'aléa
Reconstitutions
 
Observations

Fire Statistics in the Alpine Space

A preliminary analysis of collected data on the period 2000-2009 shows that the highest frequency of these fires is in Italy (74.81% of fires recorded and 71.76% of the total burnt area), followed by France (respectively 10.55% and 17.68%) and Slovenia (9.22% and 7.27 %). These areas are located in the southern climate sector and cover about 42% of the domain in question. On the contrary, the number of forest fires is smaller in countries located in the northern sector (Austria, Germany and the rest of Switzerland), accounting for only 12% of recorded events (8% of the total burnt area).

In the 2000-2009 period the Alpine region was affected by an average of 765 fires and 6,890 hectares of brunt area every year. The frequency of events and the burnt area declined after 2003, which is considered the worst year of the decade, with the exception of 2007 when the severity of fire was influenced, for example in Austria, by the accumulation of fuel resulting from damage caused by intense storms. The total burnt area (68,835 hectares) was broken down into ten classes, depending on the size, with the aim of obtaining, for each year, an indication of fire intensity (assuming that burnt area is an indicator of fire intensity).

The frequency of the so-called large fires generally decreased from 2000 to 2009. There is a significant difference across the various climate sectors: in the Northern regions of the Alps (Germany and Austria) no events were recorded in the last decade with burnt areas exceeding 50 hectares, while in the south of the Alps the size of fires attains a different order of magnitude. According to the size of fires, countries can be ranked in descending order as follows: Italy, France, Slovenia, Switzerland (Ticino and Valais), Austria and Germany.

The number of forest fires in the years considered here should however be treated with caution, as it varies considerably across the various years: data relating to longer periods would provide more reliable valuations. Furthermore, we should consider that the sources of data for the development of the fire database are rather heterogeneous, both in terms of quality and quantity of data.

The results of the basic statistical analysis (average value of burnt area, range of variation and standard deviation) of the fires included for all countries of the Alpine area show that, for the alpine forest fires analyzed, the mean value of burnt area is 9 hectares, with a peak of 15 hectares in the Southern sector (France) and a minimum of 1.2 hectares in the Northern sector (Germany).

With regard to the issue of large fires, there is no single definition currently used in the Alpine regions to classify these fires. To overcome this problem and to compare data collected for different regional areas, an assumed value for the burnt area corresponding to the 95th percentile of the distribution, was established: all fires with a burnt area above this value were considered large fires, in order to make the data homogeneous and analyze the phenomenon.
For the Alpine area considered, the value of the 95th percentile is 31 hectares of burnt area. Although forest fires with burnt areas larger than 31 hectares make up only 5% of the total number of events between 2000 and 2009, they represent 75% of the total burnt area. This value highlights the importance of analysing this extreme class of fire.
The results also showed significant differences across regions. Switzerland has the highest value (47.5 hectares), followed by France and Italy (respectively 42 hectares and 43 hectares). The minimum values were recorded in Austria (5 hectares) and Germany (2 hectares) where, unlike the other regions involved in this study, there was no fire larger than 30 hectares in the analyzed period.

The value of the 95th percentile seems to follow a combined geographical trend: the regions in the southern part of the Alps show higher values than those of the northern regions of the Alps. This phenomenon is undoubtedly linked to the different meteorological, topographical and social features of the examined areas. The effects of wind or periods characterized by low amounts of precipitation in spring and summer may affect the moisture content of the fuel much more markedly in the southern regions of the Alps than in the northern regions.
Another important factor that affects the size of the fire is the season (winter/summer) in which it occurs. In the Alpine region the highest percentage of burnt area is reached during the winter (November to April), mainly due to fires classified as small or medium fires. In contrast, fires larger than 1,000 hectares only occur in summer (May to October), when temperatures are higher. However, in France and Slovenia the percentage of burnt area is much higher in the summer (almost 70%), probably due to the Mediterranean climate component which causes drought conditions, and because of the karst substrate, characterized by low water retention.

It should be noted that in Austria the percentage of burnt area during the summer period is quite high. In this country, the fire season is concentrated during the late spring and the summer, in quite a different manner from the rest of the studied area, for which the fires frequency distribution has two peaks. The first in winter (January to April) with a frequency of 27% in March, the second in summer (July and August), with lower values (less than 10% per month). During the winter season in the alpine regions there are mostly surface fires and fires caused by fine fuel, especially below 1000 m above sea level, while ground fires and crown fires are more likely to occur in summer, as a result of long and exceptional drought periods (as in the summer of 2003).

With regard to the causes of fire, it is important to emphasize that in the Alpine region the influence of human activities is important both in terms of composition and distribution of fuel (mainly changes in land use and abandonment of rural areas) and in terms of sources of ignition (Burning of agricultural and silvicultural residues and tourism-related activities). The origin of the fire is depicted as local zoom on three neighboring regions: Lombardy (Italy), Ticino and Valais (Switzerland) and Austria. Most of anthropogenic fires occur between March and April. With regard to events caused by lightning, there is a marked difference between Lombardy, where the number of natural fires is very low (or not significant) and the other regions. In Switzerland and Austria natural fires are concentrated in the summer (June to August), with a smaller percentage in May and April, and a higher frequency in July and August. In Ticino and Valais up to 30% of events are caused by lightning. Fires of natural origin were observed at high latitudes, where lightning causes ground fires of long duration.

Modélisations

Climate change in the Alps. Future scenarios for the danger of forest fires
The impacts of global warming on the Alpine region are varied and are influenced by changes:
• in the hydrological cycle (melting glaciers, changes in precipitation, in the extent and duration of snow cover, etc...);
• in vegetation distribution (vegetation tends to move to higher altitudes and latitudes in order to find the same environmental conditions);
• in socio-economic factors (demographic trends, consumption trends, use of renewable energy, changes in land use, implementation of adjustment measures and land management policies aimed at decreasing the vulnerability of mountain environment).
In addition to these well-known issues, climate change also produces radical and unexpected impacts on fire regimes in the Alps.

The danger of fire in the future was assessed on the basis of different indexes (FWI, Nesterov, Baumgartner and others) which were calculated using data from weather forecasts resulting from the COSMO-CLM climate model simulations for the period 1990-2050. The statistical analysis on the percentiles of the index distribution values over the entire period showed the effects on the potential danger of forest fires arising from climate change in the Alps.
Focusing for example on the changes in the fire danger index, FWI (Fire Weather Index), simulations show no significant variations in the index distribution north of the Alps until the middle of the twenty-first century, although they show a trend of increasing inter-seasonal variations of the 50th percentile, which can be considered as a representative indicator of intermediate risk conditions, i.e. conditions that are somehow favourable to the development of forest fires. The trend in the internal zone of the Alps, and especially south of the Alps, is more significant: the trend regression lines for the 50th and 95th percentile (the latter a representative indicator of high or very high danger conditions), show a significant increase, which corresponds to Fig. 2 higher danger of occurrence of environmental and meteorological conditions favorable to the development of forest fires.
In addition, in the interior areas and in the region south of the Alps, the number of days in a year with a high danger of fire increases. For example, for the interior of the Alps the regional model estimates that the number of days with high fire danger, will go from 15 in 1990 to more than 20 in 2050, i.e. an increase of about 25%. As a threshold to analyze the frequency of high danger days, the 95th percentile of the distribution over the entire 60 year period was used (each year was calculated in the respective region).

For many Alpine regions, the changes estimated using the Multimodel technique [based on data from the ENSEMBLES European project] are consistent with the simulations of the COSMO-CLM regional model described above. Only north of the Alps the results obtained with the Multimodel technique predict a slight increase in fire danger, while the simulations obtained from the COSMO-CLM model show a modest decrease due to increasing precipitation.
As a preliminary conclusion, taking into account the uncertainties of climate simulations and the difficulty of climate models in representing extreme events, which for fire danger are of crucial importance, the scenarios predict an increase in forest fire danger until the middle of the twenty-first century, especially at higher altitudes and in areas south of the Alps. The frequency of days with high fire danger also shows an expected significant increase towards the half of the twenty-first century, which in some areas reaches 70 -80%.
The results obtained, albeit uncertain, show that we should be prepared to counter the possible increase in forest fires due to weather and climatic conditions through suitable and planned forest management taking into account also this type of risk, increased knowledge through scientific research, which can provide essential information for more effective suppression operations and, last but not least, strategic planning of suppression procedures on the basis of long-term goals.

Hypothèses

Europe
11 million hectares of forests in Europe are affected by various types of damage caused by fire, weather conditions such as wind and snow, insects and diseases, wild and farm animals. The damage from weather is mainly found in the Eastern-Central Europe, Western-Central Europe, Northern and South-west Europe. The damage due to fire is greater in the Russian region and in the South-East and South-West Europe. Recent studies have highlighted that the impact of climate change and other global changes on forests will increase. Research in this field suggests that the dangers to which forests are exposed, such as forest fires, caused by more frequent extreme climate events may increase considerably in the future.


Paramètre de l'aléa
Sensibilité du paramètres de l'aléa à des paramètres climatiques
Informations complémentaires (données utilisées, méthode, scénarios, etc.)
 

Forest fires in the Alps

The fire triangle

The necessary elements that determine the occurrence of a forest fire are essentially three:
• the fuel, i.e. the live part of plants (plants, shrubs, herbs) and the dead part (dry leaves or grass, fallen branches) on the ground;
• the combustion agent, i.e. oxygen;
• a source of ignition supplied by any external input, such as a flame or a lightning, which brings the fuel to ignition temperature.
The absence of even one of these components prevents the fire from starting and/or extending in time and space.

The knowledge of these factors and their evolution is very useful both before a fire develops, for effectively planning prevention, and during the fire, to ensure higher probabilities of success and safety of all those who actively participate in fire-fighting operations.

How does a fire spread?

The multiple factors related to the risk that topsoil is affected by a fire can be traced to two main categories: predisposing factors and causes.

A. PREDISPOSING FACTORS
They are related to the intrinsic properties of the area, such as the geomorphology (slope and exposure), the vegetation (composition and structure) and climate (precipitation, temperature, wind and relative humidity of air). Let us examine them in detail.

The geomorphology
The morphology of an area (altitude, slope, prevalent exposure, unevenness, etc.) determines the type of climate, vegetation and wind direction and is therefore the factor that mostly affects the risk of a fire occurring and spreading. Slope is the main morphological element that directly infl uences the spread of fire. In fact, the slope of the mountain side facilitates the advancement of fire towards the top and increases the likelihood that burning material rolls down the slope, thus generating additional spot fires. Exposure has a similar infl uence on fires. The sides that are more exposed to solar radiation (south and southwest) are characterized by higher temperatures (and therefore lower humidity) and thus are more exposed to the risk of fire.

The vegetation
The characteristics of a station (type of arboreal species, distribution, age and structure of plants) infl uence the danger of ignition, the spread and evolution of the fire in time and space. Among the most important factors that characterize the fuel in relation to the characteristics of a fire, we can list the following:
• the type of vegetation affected by the fl ames, which directly infl uences both the type of fire and its behavior;
• the amount and extent of affected vegetation;
• the fuel moisture content. The lower the water content in vegetation, the more the fire is going to spread.

The climate
As mentioned previously, the quantity of moisture in plant fuel influences the danger of fire propagation. The water content, in turn, is closely related to certain climatic factors:
• precipitation (rainfall distribution throughout the year), the risk of fire occurrence is greater during periods of drought;
• temperature that heats the fuel, dries it and brings it close to ignition temperature.
The wind increases combustion air (oxygen) and determines the development of the line of fire, causing preheating of the woody material and the transport of burning material that generates new spots where fires begins and spreads and which may be even tens or hundreds of meters away from the fire point of origin. The wind also influences the direction in which the fire spreads.
Air humidity influences the content of water in the fuel. This factor is closely related to the season in which the event occurs. The moisture content of the fuel in fact changes during the season and generally the greatest damage occurs during the vegetative season (spring-summer). In continental climate environments, characterized by low rainfall in the months of January and February, drought conditions of the vegetation due to the vegetative rest, lead to an increased risk of fire during the winter months.

B. CAUSES OF IGNITION
They are related to either natural or anthropogenic causes. While the former, consisting of lightning, spontaneous combustion or volcanic eruptions are extremely rare phenomena, the anthropogenic causes are the most significant and can be divided into:
• unintentional, negligent or accidental, resulting from human action, but without malice and attributable to carelessness or ignorance;
• intentional or malicious, with the specific intent to start a fire in order to cause damage to things or the environment or to injure people.

The main causes of ignition of forest fires:

UNINTENTIONAL CAUSES INTENTIONAL CAUSES
AGRICULTURAL AND FORESTRY PRACTICES RETALIATION OR ACTS OF VANDALISM
RECREATIONAL ACTIVITIES PYROMANIA OR MYTHOMANIA
CARELESSNESS OR NEGLIGENCE SPECULATIVE OVERBUILDING
ABANDONED CULTIVATIONS CREATING NEW JOBS
HUNTING ACTIVITIES WASTE DISPOSAL

Among the most frequent accidental causes we can mention agricultural and forestry practices, related to the removal of crop residues and forestry operations for the disposal of plant waste (brushwood, tops, etc...). Also with regard to unintentional causes, a significant portion of fires is determined by recreational activities (fires lightened on the edge of woods) or careless behaviours (cigarette butts thrown from cars).
Among the causes of intentional fire we should distinguish between those carried out in the hope of making a profit (fire with a view to transform the land from agricultural to building land, fire in order to create new jobs associated with the business of restoring the conditions of the burnt area, fires in cultivations or in the woods for farming operations and labor savings), from those which are not associated with any expectation of achieving a benefit (pyromania, revenge or personal grudges, protest). The latter are the predominant cause of fire ignition.

What are the types of fire?

Depending on the mode of fire propagation through the various layers of vegetation it is possible to distinguish four different types of fire: ground fire, surface fire, crown fire and total fire.

Ground fire: It usually develops and spreads with no flame in the organic layers above the soil mineral horizon through the roots. The dangers of this type of fire is not so much the destruction it may cause as the diffi culty in detecting and containing it. This fire is frequent in spruce forests in spot fires that may be tens of meters away from the fire point of origin. In addition these fires may cause soil subsiding due to the loss of the soil structural characteristics .

Surface fire: It is characterized by a low flame, which mainly affects low shrub and grass layers, formed by plant residues not yet decomposed. Generally, trees are affected only at the level of the trunk, while the canopy remains intact. However, if the heat exceeds a certain limit and/or the area is affected by several fires over the years, the burning of the trunk basal area may prove fatal to the plants.

Crown fire: It mainly affects the canopy of the forest spreading from the ground to foliage and sometimes from crown to crown (which is called bridge effect). The fire mainly affects conifer forests due to high resin content, as well as the presence of woody dry and very flammable material that accumulates in this type of forest. As crown fires are diffi cult to contain, they often produce a remarkable damage causing the death of most of the plants.

Total fire: Total fire is when crown fire and surface fire occur in combination forming a single flame front: the fire affects the entire extension in height of the forest. Total fire in fact affects the herbaceous, shrub and tree vegetation, and these are often very severe and destructive fires.

Fire Statistics in the Alpine Space

The key factors in the spread of forest fires (meteorological parameters, type and condition of fuel and soil) vary considerably within the Alpine region. The geography of this area, at the crossroads of the Mediterranean, the Atlantic and the Eurasian regions, affects the landscape, the shape and composition of forests, determining heterogeneous environments and populations. The local climate is influenced by two major factors: distance from the sea and altitude.
From the point of view of rainfall, in general, climate diagrams show a distribution with two rainfall peaks in spring and autumn. In addition, the combination of climate and topography gives rise to a large number of vegetation types, ranging from Mediterranean-like and Mediterranean forests, in the proximity of seas and lakes, to conifer forests similar to boreal forests, for example in Austria.

As part of the ALP FFIRS, for the first time forest fire data were shared among the countries of the alpine region. The large database developed allowed for a definition of the frequency of occurrence and the type of fires in this region during the last decade.
The database, which refers to data on forest fires occurred in the countries participating in the project, with the exception of some regions of Northern Europe, was standardized, validated and analyzed.
The database includes ten year (2000-2009) time series of daily frequency of fires occurrence and corresponding burnt areas. In order to make the dataset homogeneous, a minimum threshold for the burnt area was set, of 0.1 hectares.

Climate change in the Alps. Future scenarios for the danger of forest fires

The danger of fire in the future was assessed on the basis of different indexes (FWI, Nesterov, Baumgartner and others) which were calculated using data from weather forecasts resulting from the COSMO-CLM climate model simulations for the period 1990-2050. The statistical analysis on the percentiles of the index distribution values over the entire period, showed the effects on the potential danger of forest fires arising from climate change in the Alps.

In order for the results of the project not to be based solely on the use of a single regional climate model, the partners decided to carry out the same analysis using the Multimodel Ensemble method, i.e. using suitably combined projections of different climate models. In particular, they combined data resulting from climate simulations of seven different regional climate models, based on the same expected socio-economic scenario; these data were obtained from the ENSEMBLES European project. The Multimodel method used depends on the individual meteorological parameter and can range from the simple average of data from the models (this method is used for wind speed and relative humidity) to a new technique called SuperEnsemble Dressing used for precipitation. With regard to temperature, data from different models are built into a linear combination using “weights” that take into account the difference between the model simulations and observations in past periods. The main benefit of using these techniques is the reduction in systematic errors affecting the values of individual regional climate models; indeed, in a region characterized by very complex orography as is the Alpine region, such errors can be quite significant (for example, errors due to differences in height between the observation station and the model grid point or errors due to poor representation of atmospheric processes on a smaller scale).


(4) - Remarques générales

The ALP FFIRS project and territorial cooperation

ALP FFIRS stands for ALPine Forest FIre WaRning System, which is a warning system for Alpine forest fires. The ALP FFIRS project main objective is to reduce the risk of forest fires in the Alpine region.

How?
• By creating operational tools to support prevention.
• Dissemination of knowledge and awareness of the direct and indirect impacts of fires on forests.
• Promotion of cross-border initiatives for a synergic management of fire-fighting operations and sharing of good practices.

The project is co-financed by the European Union through the INTERREG Alpine Space Programme 2007-2013 in priority 3 “Environment and risk prevention”.

15 organizations (partners) took part in this project, from Italy, Switzerland, Austria, France, Germany and Slovenia. Indeed, it is now a given fact that only through the cooperation between Member States in the Alps can a uniform protection level against fires be assured in the region, as well as a more effective management in the border areas, the widespread application of the best suppression strategies and tactics and the progress of innovation in terms of knowledge, methodologies and tools.

This need for active cooperation on the issue of Alpine forest fires is especially pressing due to climate change on the one hand, as the increase in temperature, in the frequency of drought periods and extreme events will result in more favorable conditions to the development and spread of forest fires; and, on the other, due to limited economic resources which require the adoption of optimization measures and shared protocols.

The project partners have defi ned and adopted a shared scale for assessing forest fire danger in relation to weather conditions. On the basis of this scale, a shared warning system was developed that can provide early indications of conditions favorable to the development of forest fires. Thanks to this system timely preventive measures can be put in place as well as the management of any suppression operations.

The creation of a shared database on forest fires and related weather conditions made it possible to:
• analyze the characteristics of Alpine fires;
• assess trends, seasonality and regional peculiarities;
• identify the most representative danger indexes.

In-depth assessments of the expected impact of climate change on forest fires regime, including by comparing different methodologies, led to the definition of future scenarios indicating the need for even greater attention to this issue - and for action planning which should take into account the increased variability and frequency of conditions favorable to forest fires.

Interregional and transnational joint exercises of staff involved in prevention and suppression operations showed the potential for putting in place mutual aid permanent protocols in case of events taking place in border areas or extreme events, thus strengthening territorial cohesion in the common goal of protecting the Alpine forest.


The system for predicting forest fire danger

The main objective of the operating system for predicting forest fire danger, implemented under the ALP FFIRS project, is to support and promote the prevention and suppression of fires by leveraging on all the scientifi c knowledge developed on forest fires and on mechanisms that favor the fire ignition and propagation. The forecasting system is intended for experts and operators but at the same time it is a useful tool for informing the public about the level of expected danger.

Are you a French tourist in Slovenia and you would like to enjoy a trekking excursion in the woods along the trails winding through the trees? Where can you fi nd useful information in a language you can understand? Are you an Italian head of fire suppression operations operating in a wooded area very close to the Austrian border? You use the Canadian fire danger index FWI (Fire Weather Index) and you speak only Italian, while your colleague who is on the other side of the border is using the Nesterov danger index and speaks only German. How can you obtain information on the conditions of fire potential in your region, in the event a cross-border fire develops?

These are two examples of the problems to which the operating system developed under the ALP FFIRS project tries to respond. Through this tool it is possible to:
- collect daily information on forest fire potential in the various regions, each characterized by an operating system designed and implemented locally and each using a different language,
- provide a common map easily understood by the heads of fire suppression operations, the fire brigades, the volunteers of the forest fire-fi ghting units and the local people alike.

Therefore, the ALP FFIRS operating system is an information tool serving a dual purpose:
• it can help raise people awareness about the problem of forest fires through proper communication,
• it can facilitate cooperation between nations and between regions within the same state as it allows for an exchange of well defi ned data and provides the heads of fire suppression operations with a complete picture of the conditions of fire potential throughout the Alps.

The ALP FFIRS project supported the collaboration among experts and scientifi c researchers taking into account their different abilities, skills and experience:
• researchers in the forest fi eld contributed their knowledge on fire behavior and the methods for calculating the fire potential danger on the basis of meteorological parameters;
• meteorologists played their part by providing a better characterization of meteorological parameters in the Alpine region and by calculating the fire danger indexes;
• operating personnel (fire brigades and regional offi cials responsible for operations management and fire suppression) provided data on past fire events and made suggestions on the basis of their hands-on experience.

The joint work of all the experts made it possible to assess the best method for calculating the potential fire danger in the Alpine region, through a detailed description of fire events in the various regions. The results derived from the fire danger indexes were compared with observed fires and the index that appeared as most suitable to represent the environmental conditions in which the fires developed, for a given region in a given period of the year, was proposed along with a set of threshold values for the assessment of alert levels in the Alpine fire danger scale.

From the comparison of a large group of fire indexes for the various regions in the Alps (south-west: Hautes Alpes, Piedmont, Valle d’Aosta, Ticino, Lombardy; south-east: Friuli Venezia Giulia, Slovenia, Carinthia) a classifi cation was obtained of these indexes according to different seasons and different altitudes. On the basis of these objective assessments the local forecast systems were developed. The alert levels are calculated daily from data observed or forecast by each regional service (Meteorological Services or Regional Environmental Protection Agencies) and they are collected in order to provide the input data necessary for developing a common map.

The Alpine fire danger scale is the key of the system: although the alert levels are calculated with different methods, using different indexes and threshold values specifi c to each region, the meaning of the alert levels is equal across all the regions; this provides a valid support to experts and operational staff when assessing fire danger in neighboring regions.

This consistency also contributes to another important result: i.e. better understanding by the general public. Regardless of native languages, be it Italian, Slovenian or German, the danger levels are expressed through a 5 colors code - the orange can be interpreted as a high level of fire danger. is An example of the map produced by the system is given [in Figure 3]. The Alpine regions are represented by the fi ve colors of the danger scale; certain areas are represented in purple to indicate that data are calculated but are available on restricted or proprietary websites, as the entities responsible for fire prevention have different regulations regarding the public disclosure of this type of data. The map, which is updated daily, is available on the project website www.alpffi rs.eu, while a more detailed map in terms of geographical areas is available in a private section of the website, accessible only to experts and decision-makers, as it is intended for direct operations by fire-fi ghting crews.


The forest fire danger scale in the Alpine region

The regime of forest fires in each of the Alpine region is the result of complex interactions between fuel, topography, ignition, meteorological and social factors. The analysis of data on fire frequency and distribution over the long term provided a basis for selecting and setting the fire danger index most suitable to represent the weather conditions favorable to the development of forest fires in the various Alpine regions. However, it was necessary to defi ne a single danger scale providing a homogeneous public information on fire danger and the behaviour to adopt and, at the same time, providing fire-fi ghting crews operating in border areas with a shared perception of the potential danger of fire.

The forest fire danger scale for the Alpine region, proposed and adopted by the six countries participating in the project, the territory of which includes part of the Alps, i.e. Italy, France, Switzerland, Slovenia, Austria and Germany, consists of 5 levels of danger, depending on the conditions favourable to fire triggering and the potential behavior of fire. The scale uses colors and simple texts, which make it an ideal tool for communicating danger situations to the public.

On the basis of this single scale each region has defi ned for each level of danger:
• the preventive actions (frequency of patrolling and extent of patrolled area, equipment and means of individual units during patrolling, number of crews alerted and ready to action, increased helicopter availability),
• the diffi culties that may be encountered during fire suppression and the means necessary to address them, which depend on climate conditions and local vegetation, as well as the organization of the fire-fi ghting service.

In addition, for each level, the level of information to be provided to the public and precautions to be taken (evacuation of areas in case of interface fires, bans on areas near the fire, restriction of certain activities, closure of roads and other transport infrastructure) and the activities to be carried out after suppression, in order to prevent reignition of the fire.

The defi nition of a single forest fire danger scale, not only contributes to improved emergency actions and more effective operating procedures, it is also the basis for cross-border cooperation and operational protocols of mutual aid across the regions.

DANGER LEVEL POTENTIAL FIRE IGNITION POTENTIAL FIRE BEHAVIOR
1 - Very low Ignition is hard; use of fl ammable material is necessary Plume of white smoke. Fire spreads very slowly. No signifi cant spotting
2 - Low Low probability of ignition Plume of white and gray smoke Fire spreads slowly. Spotting frequency is low
3 - Medium A single fl ame can cause a fire Gray smoke column with dark base. Fire spreads at moderate speed. Spotting frequency is medium
4 - High A single fl ame will certainly cause a fire Fire spreads at high speed Spotting frequency is high
5 - Very high A single spark can cause a fire Column of black smoke. Fire spreads very fast. Intense spotting

The 5 level forest fire danger scale defi ned in the ALP FFIRS project and shared by the Alpine countries


What to do

Knowing what to do and how to behave when you are in a risk situation is essential to help and protect yourself and facilitate the work of rescuers.
• Behaving appropriately in order to avoid causing a fire is as important as knowing how to guard against fires and alert rescuers in case of need.

How do you avoid causing a fire?
In order to avoid the triggering of fires in areas covered by natural vegetation, including roadsides, especially if you are in abandoned wooded areas with trees:
• do not throw matches and cigarettes, including when you are on board vehicles;
• do not light fires, braziers, stoves, furnaces, gas appliances or appliances with hot parts;
• do not use open fl ames or tools that may cause spreading fl ames or sparks Barbecues, gas or other fuel stoves must be used in picnic areas or in totally secure areas;
• do not burn garbage, road and railway embankments, river banks, cultivation residues and residues of abandoned grasslands or wooded areas;
• do not to burst firecrackers, fireworks or other pyrotechnic products;
• take care to park your car in safe areas, far from dry vegetation: even a catalytic converter can ignite a fire;
• when carrying out works, do not use tools or products that may cause sparks or combustion, free fl ames or explosives;
• in the case of property, rural buildings, or activities that require electrical systems, keep the systems and electrical wires in good condition to avoid electrical shock or damage;
• in any case, also for the activities described above, make sure that vegetation and weather conditions are compatible with the activities you intend to carry out. Strong wind may cause incandescent material to travel long distances and in a very short time any spot fire may turn into an uncontrollable fire, because of the drought.

What should you do when there is a fire?
• keep at a safe distance and look for a safe escape route, such as a road or a watercourse;
• do not stop in places that are in the direction of the wind;
• avoid breathing the smoke, including by lying down on the ground in a place where there is no fl ammable vegetation;
• go to a safe place, and if you have no other choice, try to cross the fire where it is less intense in order to move to the already burnt area;
• do not to interfere with operators and means by stopping to look at a fire;
• comply with signs forbidding passage placed by fire fighters.

If you see a fire, immediately call the national emergency numbers and provide information necessary to locate the fire.

If you are in Italy call 1515 or 115
If you are in Slovenia call 112
If you are in Austria call 122
If you are in Germany call 112
If you are in France call 18
If you are in Switzerland call 118
ON THE PHONE:
• keep calm and speak clearly
• indicate as accurately as possible the location where the burning area is located
• specify if on site there are already crews engaged in suppression operations
• do not hang up until told so by the operator or the operator has repeated the message


Documentation of fires in the Alpine region

Why is it important to gather information about a fire?
Documentation and retrospective analysis of forest fires is of great value both as a training tool and as a source of data for research. The notion of considering forest fires as a source of data is essential for studying empirical frameworks predicting fire behavior, which are based, in whole or in part, on such data. This is even more important for fires that reach extreme values in the fire intensity scale, for which it is difficult to replicate experiments.
The information derived from data on forest fire behavior also plays a signifi cant role in the testing and evaluation of fire propagation models, in the validation of theoretical assumptions, in the systems supporting decision-making and in the guidelines for the management of fire. During the development of the ALP FFIRS project, the collection and analysis of case studies was strategic for the following reasons:
• it contributed to increasing knowledge of forest fires in the Alpine region and highlighted the specifi city of this region, where only few cases were documented in the past;
• it allowed a transfer of knowledge from current to future stakeholders;
• it allowed matching fire behavior with fire danger, providing information for direct in-the-fi eld interpretation of fire danger levels.

Analysis of case studies
When preparing a report following a forest fire, it is important to organize all the information gathered from different sources and of different type in a consistent and structured description. A good approach to follow is to interview the operators who took part in suppression operations in order to obtain information from different points of view.
During the project, the case studies concerning significant fires were described using a standard card, derived from the Fire Paradox and MANFRED projects, about past events. The main objective was to associate the fire behavior and the operational procedures adopted to the level of risk assessed during the event. The essential information are summarized in the first page (Figure 1], where the “signature” of the fire (fire type) is highlighted, as well as the indicators of the intensity of the fl ame front (flame length at the head of the fire) and danger levels.

A typical shortcoming of most forest fire analyses is that the detail and the sequence of operations carried out by the operators to keep the fire under control hide the actual fire behavior . Normally in fact all participants are so engaged in operations to manage the emergency that no one is available to make objective and on-going observations of the fire itself. Thus the fire general behavior and in particular the time and sequence of signifi cant changes in its behavior are uncertain and diffi cult to be derived from the evidence provided. It is essential to record the position of the fl ame front at the various instant times: the more numerous the observations the better.

The card shown [as exemple] contains other information such as:

  • weather conditions: description of weather conditions on a large scale through representative maps, relevant meteorological data (main winds, wind changes, drought, dust storm), coordinates or exact location of the reference weather station (altitude, surroundings), hourly charts of meteorological parameters and danger indices, such as graphs of hourly temperature, relative humidity, wind speed and direction. It is advisable to establish permanent relations with local meteorologists and take advantage of their assistance in preparing the card;
  • maps of forest fire danger and time trend of danger indexes based on meteorological factors;
  • fire behavior and suppression operations; a brief description of the main operations put in place in relation to fire behavior and map of the fire propagation direction and intensity;
  • image gallery during and after the event;
  • event impact on the ecology and the economy:
    - pre-event management, such as the conditions of the forest and the surrounding vegetation, forest management mode, public or private ownership, prevention operational protocols, risk awareness;
    - impacts and economic damage, including: impairment of ecosystem services, consequences for humans, the possibility of quantifying the economic damage, trying to answer the question “is the event considered extreme and why?”;
    - post-event strategies adopted, including the management of the forest after the event (did the fire affect the forest management policies or will it do so in the future?), economic management of the post-event situation, side or otherwise monitored events;
  • lessons learned.

Several case studies were collected by the ALP FFIRS project partners. The respective cards are associated with the daily fire danger map in the Alpine region, in order to provide interested parties with practical examples of fire behavior for a specifi c danger level, location and time of year.

What are the fires characteristics?
The main result of the collected case studies is certainly that of setting off a sort of “Alpine Awareness”. What was already known from the literature with regard to forest fires in the Alpine region is now confi rmed in real life situations as experienced and reported by the operators. At the same time, we can identify specifi c issues that should be thoroughly investigated and abnormal fire behaviors linked to climatic factors. The Alps are a fragile environment, highly exposed to the effects of global warming. This is why the anomalies recorded in alpine fires can represent a sort of “barometer” of climatic anomalies in general. Some examples are described:

It is known from the literature that the heterogeneity of the landscape and crops leads to heterogeneity in fire behavior. On the one hand, the uneven conditions of the vegetation and the soil is clearly refl ected in Alpine fires. For example, in the fire that took place in March 2012 in Zolla, Villa Opicina (Friuli Venezia Giulia, I), the fire affected the prairies, pine forests and broadleaf forests, on an undulating karst soil. The landscape heterogeneity makes predicting the fire propagation more complex but at the same time, a mosaic of different forest fuels can be advantageous, as, unlike fires in the Mediterranean pine forests, in these cases the fire intensity does not increase in a continuous manner over time.

The maximum intensity values of the fl ame front resulting from a preliminary assessment of the propagation of the fire potential extension, suggest a non-extreme intensity of winter fires in Austria and Veneto (I). Values of around 1850 kW/m and 2660 kw/m have been estimated respectively for pine and chestnut forests. The analysis of the events shows that the fires causing the greatest damage are those occurring in forests of Pinus Sylvestris on the southern slopes and in the Continental valleys, such as, for example, the behavior of some extreme fires observed in Valle d’Aosta (I). In these situations, a critical factor is the dry down-slope wind (foehn wind). Such a confi guration can be found in Piedmont and Lombardy (I). On the other hand, the variety of cultures and languages is especially crucial in fires affecting border areas, such as the fire occurred in August 2003 in Sela na Krasu, which had begun in Italy and later extended to Slovenia, where most of the burnt area is located.

Basically, the forest fire system in the Alps is characterized by anthropogenic winter surface fires that spread rapidly at medium-low altitudes and ground fires ignited by lightning during the summer (July-August). The fires that occur in winter are the most frequent. Generally, grazing and light fuels (broadleaf litter) burn without producing a crown fire (fire of Monte San Mauro, Veneto). In some cases, the fire extinguishes spontaneously due to the presence of snow on the North facing slopes, as it is the case in the inner valleys (Valle d’Aosta, I).

A factor that, while in theory could benefi t fire fi ghting operations, in practice makes accessibility harder (icy and slippery roads) and results in a lack of suppression resources (icy water in the tanks).

Fires recorded in the summer show two different patterns: man-induced fires comparable to the large Mediterranean fires and slowly spreading ground fires. In Slovenia (Karst) and France, the fires developed in the summer 2003 were extreme fires in terms of behavior and intensity. In Veneto, the fire sparked by lightning in Caralte (August 2003) burned only 38 hectares, but highlighted the main diffi culties in the extinction of Alpine fires: i.e. the issues of safety and high costs due to the diffi culties in accessing the steep slopes of the mountains as well as the impact of smoke on tourist facilities. The fire lasted about 40 days and huge costs for the use of aircraft were incurred in order to completely suppress the fire. In addition, the topographic gradient and frequent thermal inversion are recognized as the most critical elements in the extinction of most fires. An example is the fire of Monte San Mauro, which occurred in Veneto (I) in February 2011. In Austria, a serious issue arose in 2006, i.e. an increase in the danger level due concomitant natural factors. The damage to the trees caused by the wind and the consequent attacks by beetles led to a worsening of the fire situation, an effect that had never occurred previously.

Most of the anomalies in fire behavior in the last twenty years occurred during 2003, 2006 and 2011. 2003 has been identifi ed, not only in the Alpine region, as a year of extreme drought with exceptional summer temperatures. In both 2003 and 2006 an abnormal increase in forest fires was recorded, especially in Valle d’Aosta, Carinthia and Friuli Venezia Giulia, where lightning fires accounted for about 20-30% of the total number of events. During 2011, an extreme fire occurred in the north-east of Italy at the beginning of the growing season (May 2011, fire in La Muda, Veneto) in a coniferous forest, showing a behavior totally out of the average for that period of the year when usually forest fires do not occur. In Friuli Venezia Giulia, a fire was started by lightning during the early spring (March-April 2011) near Tramonti (PN), albeit lightning fires are usually associated with the summer season.

The scope of the project
The collection of case studies carried out during the ALP FFIRS project must be expanded and updated over time. These initial results, derived from the preliminary analysis of these cases have an important repercussion for the project and for the dissemination of a shared mode for collecting data and information during a fire. They also outline the lines of future development in research. A new cultural approach to the study of forest fires was initiated by collecting the fi rst fire cards. The hope is that it will be strengthened, because it is the most effective way to combine the indications on the level of fire danger with the expected scenario, for the protection of all those involved in fire fi ghting; it may also function as a key common platform on which scientists and operating personnel can share knowledge and experience.


(5) - Préconisations et recomandations
Destinataires et portée du rapport

This paper describes the work and results carried out by the ALP FFIRS - ALPine Forest FIre waRning System - project partners, as part of the Interreg Alpine Space 2007-2013 Programme.
The purpose of this booklet is to help disseminate information on forest fires and their impact on the forest heritage and, indirectly, on several social and economic aspects of the Alpine region. Indeed, it is the belief of the project partners that knowledge and individual awareness of this issue may help limit the spread of the phenomenon and contribute to the preservation and protection of the forest and the environment.
Chapter 7 “What to do” is precisely focused on actions. These can be either individual actions, i.e. individuals’ daily cares to prevent fires, and collective initiatives such as exchange of experiences and joint crossborder training to facilitate cooperation and synergies at the international level for the protection of the alpine forest.
And finally, the paper presents the main results of the project, intended to provide a lasting contribution with regard to information and management of the active fight to forest fires:
• The single scale to classify fire danger and harmonize prevention and suppression activities in the various alpine regions,
• The shared warning system that helps prevent the development of forest fires and ensures effective fire-fighting activities.

Types de recommandations et / ou préconisations  

Références citées :