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

ASSESSMENT OF SPECTRAL INDICES DERIVED FROM MODIS DATA AS
FIRE RISK INDICATORS IN GALICIA
M.M. Bisquert 1
1 Earth Physics and Thermodynamics Department, University of València,
Burjassot, España
Maria.Mar.Bisquert@uv.es
J.M. Sánchez 1-2 , V. Caselles 1 , M.I. Paz Andrade 3 & J.L. Legido 4
2 Applied Physics Department, University of Castilla-La Mancha, 02071, Albacete, España
3 Applied Physics Department, University of Santiago, Santiago de Compostela, España
4 Applied Physics Department, University of Vigo, Vigo, España
Abstract: The Galicia region, placed at the northwest of Spain, is an area
specially affected by the action of fire. It is known that fires can be related
to the water status of the vegetation. Variations in water content produce
changes in the visible and infrared regions of the spectrum. These
characteristics permit us to monitor the changes in the vegetations status
and relate them to fire probability using remote sensing. There are many
vegetation and moisture indices that have been used to monitor the vegetation
status. However, the different indices do not work the same in different
vegetation species. Thus, a study is necessary to determine the most
appropriate index to monitor the vegetation status in our study area. For
the present work we have selected eight indices from the bibliography, and
we have compared their feasibility as fire risk indicators. Overall, results
show that we can use either, EVI or GEMI, to monitor fire risk in Galicia
with a relative error of about 15%.
1 - Introduction
Forest fires are an extremely destructive phenomenon for nature. In Spain,
forest fires are very abundant. Prevention is an important issue in the fight
against fire. There are a wide number of models which try to obtain a forest
fire risk indicator using multiple variables. The aim of this work is to
analyze the isolate potential of the information about the vegetation status
as a new parameter to be included in the fire prediction systems in the
Galicia region by the use of remote sensing techniques.
Many works have studied the relation between the vegetation status and
forest fires using spectral indices. Nevertheless, a universal relation
between these indices and fire probability has not been found. Therefore it
is necessary to obtain, for each case, the most appropriate index which best
characterizes the changes in the vegetation status, and so, better represents
the relation between forest fires and the vegetation status.
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