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| Titel |
Post-fire vegetation recovery in Portugal based on spot/vegetation data |
| VerfasserIn |
C. Gouveia, C. C. Dacamara, R. M. Trigo |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 10, no. 4 ; Nr. 10, no. 4 (2010-04-08), S.673-684 |
| Datensatznummer |
250008073
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| Publikation (Nr.) |
 copernicus.org/nhess-10-673-2010.pdf |
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| Zusammenfassung |
| A procedure is presented that allows identifying large burned scars
and the monitoring of vegetation recovery in the years following
major fire episodes. The procedure relies on 10-day fields of
Maximum Value Composites of Normalized Difference Vegetation Index
(MVC-NDVI), with a 1 km×1 km spatial resolution obtained
from the VEGETATION instrument. The identification of fire scars
during the extremely severe 2003 fire season is performed based on
cluster analysis of NDVI anomalies that persist during the
vegetative cycle of the year following the fire event. Two regions
containing very large burned scars were selected, located in Central
and Southwestern Portugal, respectively, and time series of MVC-NDVI
analysed before the fire events took place and throughout the
post-fire period. It is shown that post-fire vegetation dynamics in
the two selected regions may be characterised based on maps of
recovery rates as estimated by fitting a monoparametric model of
vegetation recovery to MVC-NDVI data over each burned scar. Results
indicated that the recovery process in the region located in Central
Portugal is mostly related to fire damage rather than to vegetation
density before 2003, whereas the latter seems to have a more
prominent role than vegetation conditions after the fire episode, e.g.
in the case of the region in Southwestern Portugal. These
differences are consistent with the respective predominant types of
vegetation. The burned area located in Central Portugal is dominated
by Pinus Pinaster whose natural regeneration crucially
depends on the destruction of seeds present on the soil surface
during the fire, whereas the burned scar in Southwestern Portugal
was populated by Eucalyptus that may quickly
re-sprout from buds after fire. Besides its simplicity, the
monoparametric model of vegetation recovery has the advantage of
being easily adapted to other low-resolution satellite data, as well
as to other types of vegetation indices. |
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