7th Workshop on Forest Fire Management - EARSeL, European ...

OPERATIONAL USE OF REMOTE SENSING IN FOREST FIRE MANAGEMENT
IN PORTUGAL
Abstract: Like other southern regions of Europe, Portugal has experienced
a dramatic increase in fire incidence during the last few decades that has
been attributed to modifications in land-use (e.g. land abandonment and
fuel accumulation) as well as to climatic changes (e.g. reduction of fuel
humidity) and associated occurrence of weather extremes. Wildfire activity
also presents a large inter-annual variability that has been related to
changes in the frequency of occurrence of atmospheric conditions
favourable to the onset and spreading of large-fires. The aim of the present
study is to provide evidence that levels of fire risk prior to the beginning
of the fire season may be anticipated by using information about vegetation
stress at the beginning of the fire season (e.g. as derived from vegetation
indices based on remote-sensed data) and combining it with longrange
weather forecasts (e.g. in the form of fire risk indices based on summer
climatic outlooks).
1 - Introduction
C.C. DaCamara
CGUL, IDL, University of Lisbon, Lisbon, Portugal
cdcamara@fc.ul.pt
T.J. Calado, C. Gouveia
University of Lisbon, Lisbon, Portugal
mtcalado@fc.ul.pt; cmgouveia@fc.ul.pt
In the European context, Portugal presents the highest number of fire
occurrences and has the largest areas affected by wildfires (Trigo et al.,
2006). In this respect, vegetation is known to play an important role since
it drives fuel accumulation, which exerts a control on fire behavior, especially
in the case of fires burning under less severe weather conditions.
However, meteorological and climatic factors play a crucial role in fire
behavior. As pointed out by Pereira et al. (2005), more than 2/3 of the
inter-annual variability of burned area is explained by meteorological factors
namely i) the temperature and precipitation regimes of the spring preceding
the fire season and ii) the occurrence during the fire season of circulation
patterns of short-duration that induce extremely hot and dry spells
over western Iberia.
Using remote sensed information to monitor vegetation stress during the
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