Proceedings of the Second International Symposium on Fire Economics, Planning, and Policy: A Global View
Fire Management Plan at Regional Scale in
an Alpine Fire-Prone Area (Valle d’Aosta
Region - Italy)1
Giovanni Bovio,2 Elisa Guglielmet,3 Andrea Camia4
Abstract
In this contribution the methodology for the development of the fire management plan at
regional scale based on the new Italian regulation on wildland fire protection (L.353/2000) is
presented. In particular the main features of the recent regional fire management plan
finalized for Valle d’Aosta region according to the mentioned regulation are described, with a
specific focus on the criteria used to define and spatially distribute protection priorities.
Located in the extreme Northwestern part of Italy, Valle d’Aosta is the smallest and the most
mountainous of the Italian regions, characterized by an Alpine environment, a main central
valley East-West oriented and a total area of about 3262 km2. In this region, as in general in
Northern Italy, wildfires are concentrated in the winter-early spring season, in agreement with
the driest period of the year. Spatial analysis techniques made with a GIS to derive land
zoning from fire related variables in order to support the development of the fire management
plan are reported, together with the criteria followed to define the protection priorities at
regional scale.
Introduction
The protection of forests against wildfires can be successfully realized only with the
support of a wildfire management plan.
In Italy forest fire management plans at regional scale are based on the wildland
fire protection national law L. 353/2000. This regulation establishes new rules to
reduce burned areas, enhancing fire prevention and wildfire danger rating systems.
Italian regulation on wildland fire protection and its guidelines define the main
arguments that must be analyzed in regional plans.
According to the prescriptions of the general policy forest fire general law, the
fire management plan of Valle d’Aosta Region, one of the 20 Italian regions, was
accomplished. The present contribution shows the main phases of the work realized
An abbreviated version of this paper was presented at the second international symposium on fire
economics, planning and policy: a global view, 19–22 April 2004, Cordoba, Spain.
2 Full Professor, Dept. Agroselviter, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco
(TO) Italy. email: giovanni.bovio@unito.it.
3 Forest Engineer, Dep. Agroselviter, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco
(TO) Italy. email: elisa.guglielmet@unito.it.
4 Doctor in Forestry, Dep. Agroselviter, University of Turin, Via Leonardo da Vinci 44, 10095
Grugliasco (TO) Italy. (Current affiliation: Joint Research Centre, Institute for Environment and
Sustainability - TP 261, I-21020 Ispra (VA) Italy. email: andrea.camia@jrc.it).
1
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Session Poster— Fire management plan in Alpine region — Bovio, Guglielmet, Camia
to produce this fire management plan, with particular attention to the criteria used to
define and spatially distribute protection priorities.
Objectives
The objective of the present work is to describe a methodology for setting up wildfire
management plans at regional scale. In particular the first objective is to provide the
regional fire managers with an operative plan to address fire planning procedures and
operative services, linking together different sectors of fire management activities.
The attention is pointed out on the modalities to spatially distribute protection
priorities and, in general, to define fire risk mapping process at regional scale in an
Alpine area, in which wildfires season is concentrated in the winter-early spring
months. For this reason we have chosen to describe the methodology followed for the
wildfires management plan of Valle d’Aosta region.
Study area
Valle d’Aosta Region is located in the North-Western extremity of Italy, bordering
on Switzerland to the North, on France to the West, on Piedmont to the South and
East. It is characterized by a total surface of about 3,262 km2, 1,080 km2 of which
covered by forests. The territory is mainly mountainous and the average altitude is
2,100 meters, with a range that goes from about 295 m to 4,800 m a.s.l.. Considering
the administrative divisions, Valle d’Aosta Region presents only one province,
divided into 74 municipalities. For its collocation and its climatic conditions, Valle
d’Aosta forest fire distribution during the year is the typical one of the Regions of the
Alpine range, with a fire season that extends from November to April and with few
summer fires. The following figure shows the location of Valle d’Aosta Region
(fig.1).
Figure 1 – Location of Valle d’Aosta.
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USDA Forest Service Gen. Tech. Rep. PSW-GTR-xxx. xxxx.
Proceedings of the Second International Symposium on Fire Economics, Planning, and Policy: A Global View
Session Poster— Fire management plan in Alpine region — Bovio, Guglielmet, Camia
Methodology
Statistics on forest fires
For the redaction of a wildfire management plan a preliminary issue is to give an
historical summary of the wildfire situation of the study area. A database of wildfires
and the basic cartography are required to make landscape analysis and statistical
elaboration. The period considered in the study area is made of 17 years, from 1986
to 2002. The data were obtained from the Forest Service of Valle d’Aosta. In the
following table a summery of the historical wildfire data is given (table 1).
Table 1– Main statistical variables for the considered historical series (1986 – 2002)
# Fires
Total burned area
Forest burned area
Non forest burned area
Average burned area by fire
Total
366
2,785 ha
1,666 ha
1,119 ha
-
Annual average
22
164 ha
98 ha
66 ha
7.6 ha
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GENERAL TECHNICAL REPORT PSW-GTR-208
Session Poster— Fire management plan in Alpine region — Bovio, Guglielmet, Camia
Fire Risk Zoning
Fire risk zoning is meant as the definition for wildfire protection purposes of
homogeneous areas having similar fire risk level.
In the present study the basic geographical unit to which information on fire
events has to be referred is the municipality. For each municipality many parameters
were calculated and analysed to define risk classes and their spatial distribution. A set
of variables related in particular to fire frequency and fire characteristics has been
selected to describe the pirological situation of each municipality. These variables
together are able to define a “fire history profile” of each municipality.
The variables considered for each municipality are the following:
-
Number of forest fires per unit area (10 km2) per year. This feature expresses a
measure of the average concentration of wildfires in the territory.
-
Number of “large fires” per unit area (10 km2) per year. This expression of
concentration is limited to events that for their size have been considered
exceptional for the whole regional territory. The surface threshold for
discriminating “large fires” was derived from statistical analysis that considers
the frequency distribution of area burned by forest fires. For Valle d’Aosta
Region “large fires” correspond to fires with a surface burned of almost 8
hectares. They are the 10 percent of the total fires occurred in the Region
during the historical period considered, corresponding to a surface of about the
80 percent of the total burned area in the same period.
-
Number of “small fires” occurred per unit (10 km2) area per year. This
variable expresses the mean concentration of fires whose area burned is less
than 0.5 hectares. This extent threshold of “small fires” is defined by Valle
d’Aosta Forest Service and is used to define the potential susceptibility to fires
of the Region considered.
-
Number of years with least one event during the period considered in
percentage. This variable estimates the time continuity of the phenomenon.
-
Mean area burned by a single event. This variable synthesizes average fires
dimension for each municipality, but it is influenced by the extreme values of
the distribution, which is typically strongly asymmetric.
-
Median area burned by a single event. This is the value of burned area that
divides the area burned sorted values of into two equal parts. Below and above
this value 50 percent of occurrences of fires in a municipality are found.
Median area burned by a single fire represents the area burned by the so-called
“typical fire”.
-
Maximum area burned by a single event. It is the area burned by the largest fire
occurred during the historical period for each municipality.
From the analysis of the previous variables, history profiles of the municipalities
were calculated. Then, through hierarchical cluster analysis applied with Ward
method (Ward 1963), it was possible to define 5 municipality groups for Valle
d’Aosta Region. Each group defines a risk class, which is synthetically described by
the centroid value of the profile variables, i.e. the mean value computed for each
variable of all the municipalities that belong to a risk class. In the following table
(table 2) the centroids of the 5 risk classes of the 74 Valle d’Aosta municipalities
derived from classification applied are showed.
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Proceedings of the Second International Symposium on Fire Economics, Planning, and Policy: A Global View
Session Poster— Fire management plan in Alpine region — Bovio, Guglielmet, Camia
Table 2 - Centroids of fire risk classes
Number of municipalities
Number of fires per year per 10 km2
Number of fires > 8 ha (large fires) per year per 10 km2
Number of "small fires" per year per10 km2
Years with fires (pct)
Mean area burned by one fire (ha)
Median area burned by one fire (ha)
Maximum area burned by one fire (ha)
Number of fires per year
Number of fires > 8 ha per year
Number of "small fires" per year
Burned area per year (ha)
1
12
0.0
0.00
0.3
0.0
0.0
0.0
0.0
0.0
0.00
0.6
0
Municipality fire risk classes
2
3
4
5
44
10
3
5
0.1
0.3
0.2
0.8
0.01
0.02
0.05
0.11
0.4
2.1
1.1
2.7
15.4
37.6
41.2
54.1
6.1
3.4
31.4
7.7
4.9
1.1
3.7
2.2
12.4
23.0
266.3
60.4
0.2
0.7
0.6
1.3
0.02
0.05
0.16
0.20
1.0
4.7
3.9
4.0
0.9
2.5
18.4
8.5
The fire risk zoning allows to define and characterized homogenous areas and to
put municipalities in ordinal scale in order to distribute protection resources at
Regional scale. In the following figure municipalities classified into the fire risk
classes are represented (fig.2).
Figure 2 - Map of fire risk classes in Valle d’Aosta Region.
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GENERAL TECHNICAL REPORT PSW-GTR-208
Session Poster— Fire management plan in Alpine region — Bovio, Guglielmet, Camia
Aims zoning
Results obtained from zoning process are used to define different planning objectives
that are established according to criteria, such as acceptable fire impact and its
distribution within the homogeneous areas previously defined.
Through a more detailed analysis, within each municipality the areas where fire
protection activities have a priority importance were defined. To define these areas
and to give them a protection priority level, spatial analysis with Geographical
Information System (GIS) techniques were made. GIS can provide useful tools for
wildfires management, through their capability of handling in an integrated
environment multi-source and multi-resolution spatial data (Burrough and
McDonnel, 1998).
The following spatial data layer were integrated using ARC-GIS 8.3 by ESRI:
-
Elevation: derived from Digital Elevation Model (DEM).
-
Aspect: derived from Digital Elevation Model (DEM).
-
Forest types: a value based on the inflammability of the species was given to
each forest type.
-
“Large fires” location: the perimeter of all forest fires with a burned area
greater than 8 hectares was digitalized.
Through GIS analysis the different layers were overlayed and merged deriving 5
different protection priority levels in the study area. The following figure shows the
spatial distribution of the protection priorities at regional scale (fig.3).
Figure 3 - Map of protection priorities.
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Proceedings of the Second International Symposium on Fire Economics, Planning, and Policy: A Global View
Session Poster— Fire management plan in Alpine region — Bovio, Guglielmet, Camia
The protection priority classification of the regional territory has to be used
together with the fire risk classification. The fire risk classes define the priority rank
of the municipalities. Then the protection activities will be planned starting from the
municipalities with the higher risk and then considering, for each municipality, the
protection priority levels.
Interventions zoning
This part of the fire management plan has the objective to describe prevention and
extinction activities that have to be realized and distribute them in the regional
territory. In the present work these activities are not presented in detail, but only the
main categories of interventions foreseen are briefly described.
The interventions zoning concerns the following activities:
-
Meteorological Fire Danger Rating. At the moment in Valle d’Aosta Region
the Canadian Fire Weather Index (Van Wagner 1987) is operationally used.
For the computation of FWI daily meteorological data are used. Within the fire
management plan the index was calibrated with the method described by Van
Wagner (1987) applied on a monthly basis. The daily fire danger classes are
meant to be linked to the real time operational activities.
-
Direct Prevention activities. This category of interventions includes different
activities:
-
Preventive Silviculture
-
Firebreaks
-
Prescribed fire
-
Forest and operative viability
-
Watering
-
Helicopters
-
Indirect Prevention activities. The main actions of this category are
educational activities, turned in particular to students. The main purpose is to
reduce fire ignition causes and to give suggestions concerning the correct
behaviour to adopt in case of wildfire.
-
Extinction activities.
-
Restoration.
-
Decision support Systems and Control Center
-
Firefighters Training.
Discussion and Conclusions
Planning activities are fundamental to reduce forest fires and the consequent burned
area.
The methodology followed to set up the fire management plan of, a typical
Alpine fire-prone area located in Italy (Valle d’Aosta Region), is presented. Planning
choices suitable at a regional scale are outlined, describing variables to be selected
and the way to join them in order to define homogeneous areas where a protection
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GENERAL TECHNICAL REPORT PSW-GTR-208
Session Poster.— Fire management plan in Alpine region — Bovio, Guglielmet, Camia
level and priorities can be defined. The main steps and criteria followed for the
zoning process are presented and the results obtained from the zoning task are
showed. These have been used in the fire management plan to define different
planning objectives.
Fire management planning at regional scale is a complex process in which
different items and purposes have to be integrated and considered with a global
perspective. Taking into account Italian fire management requirements, the research
has shown that the most appropriate approach for regional fire management planning
has at first to consider the area interested by the plan as a whole and then to proceed
with the analyses at a more refined detail.
Acknowledgments
This research was funded by the Regione Valle d'Aosta, Assessorato Agricoltura,
Risorse Naturali e Protezione Civile, Dipartimento Risorse naturali, Corpo Forestale,
Protezione Civile e Antincendi, Direzione Foreste.
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Bovio, Giovanni 2001. La Pianificazione antincendi boschivi alla luce della Legge
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Bovio, Giovanni; Camia, Andrea 1994. Fire danger zoning using multivariate analysis. In:
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Burrough, P.A.; McDonnell, R. A. 1998. Principles of Geographical Information Systems.
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