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| Titel |
Size of wildfires in the Euro-Mediterranean region: observations and theoretical analysis |
| VerfasserIn |
C. Hernandez, P. Drobinski, S. Turquety, J.-L. Dupuy |
| 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 Sciences ; 15, no. 6 ; Nr. 15, no. 6 (2015-06-23), S.1331-1341 |
| Datensatznummer |
250119540
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| Publikation (Nr.) |
 copernicus.org/nhess-15-1331-2015.pdf |
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| Zusammenfassung |
| MODIS (Moderate Resolution Imaging Spectroradiometer) satellite observations of fire size and ERA-Interim meteorological
reanalysis are used to derive a relationship between burnt area and wind
speed over the Mediterranean region and Eastern Europe. The largest wildfire size
does not show a strong response with respect to wind speed in Eastern Europe.
In the Mediterranean, as intuitively expected, the burnt area associated with
the largest wildfires is an increasing function of wind speed for moderate
temperature anomalies. In situations of severe heatwaves, the relationship
between burnt area and wind speed displays a bimodal shape. Burnt areas are
large for low 10 m wind speed (lower than 2 m s−1), decrease for
moderate wind speed values (lower than 5 m s−1 and larger than
2 m s−1) and increase again for high wind speed (higher than
5 m s−1). To explain such behavior we use a stochastic model of fire
propagation, known as a probabilistic cellular automata. This model uses a
probabilistic local rule to derive the total burnt area. The observed
relationship between burnt area and wind speed can be interpreted in terms of
percolation threshold above which the propagation in the model is infinite,
which mainly depends on local terrain slope and vegetation state (type,
density, fuel moisture). In Eastern Europe, the percolation threshold is
never exceeded for observed wind speeds. In the Mediterranean Basin we see
two behaviors. During moderately hot weather, the percolation threshold is
passed when the wind grows strong. On the other hand, in situations of severe
Mediterranean heatwaves, moderate wind speed values impair the propagation of
the wildfire against the wind and do not sufficiently accelerate the forward
propagation to allow a growth of wildfire size. |
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