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

MONITORING POST-FIRE VEGETATION REGENERATION OF THE 2003
BURNED AREAS IN PORTUGAL USING A TIME-SERIES OF MODIS
ENHANCED VEGETATION INDEX
P. Malico
Department of Forestry, School of Agronomy, Technical University of Lisbon,
Lisboa, Portugal, patmalico@isa.utl.pt
J. Kucera 1 , J. San-Miguel Ayanz 1 , B. Mota 2 , J.M.C. Pereira 2
1 Joint Research Centre, Institute for Environment and Sustainability, Land Management and Natural
Hazards Unit, Ispra (VA), Italy, jan.kucera@jrc.it; jesus.san-miguel@jrc.it
2 Department of Forestry, School of Agronomy, Technical University of Lisbon,
Lisboa, Portugal, bmota@isa.utl.pt; jmcpereira@isa.utl.pt
Abstract: Our objective is to monitor vegetation recovery after the large
fires of 2003 in Portugal. We use a time-series of MODIS Terra Enhanced
Vegetation Index (EVI) data, at 250 m spatial resolution and with 16-day
image composites (MOD13A1 product). These data were screened with the
Time Series Generator (TiSeG) software, to detect and replace bad or missing
data. The analysis begins in early 2000, to characterize pre-fire vegetation
dynamics, extends until late 2008, and relies on fire perimeters
mapped from Landsat imagery at 30m spatial resolution to locate the 2003
fires. Three sample fires were selected for preliminary visual analysis of EVI
time series within and outside the fire perimeters, and observed differences
are discussed as a function of pre-fire land cover.
1 - Introduction
The Mediterranean climate is characterized by the coincidence of the hot
season with the dry season and rainy winters (Efe, Cravins et al., 2008).
This particular aspect of weather conditions determines that is one of the
world’s major fire-prone biomes where fire controls structure and vegetation
dynamics (Naveh, 1975; Bond and Keeley, 2005), since plant communities
have high resilience to fire and many regenerate by resprouting from fire
resistant structures (Arnan, Rodrigo et al., 2007). The objectives of the
present study are: to monitor vegetation recovery in areas burned in
Portugal during the extreme fire season of 2003; to quantify the rate of
vegetation recovery at spatial scales ranging from pixel to region; to identify
spatial environmental correlates of vegetation recovery rates, and
quantify their relative importance as explanatory variables. Wildfires have
broad impacts, affecting the production of environmental goods and services
through impacts on biodiversity, soils, water resources and air quality.
Detailed spatio-temporal monitoring of post-fire vegetation recovery is
important to help forecast negative environmental impacts, such as land-
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