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| Titel |
Simulating statistics of lightning-induced and man made fires |
| VerfasserIn |
R. Krenn, S. Hergarten |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250027775
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| Zusammenfassung |
| The frequency-area distributions of forest fires show power-law behavior with scaling
exponents α in a quite narrow range, relating wildfire research to the theoretical framework of
self-organized criticality. Examples of self-organized critical behavior can be found in
computer simulations of simple cellular automata. The established self-organized critical
Drossel-Schwabl forest fire model (DS-FFM) is one of the most widespread models in this
context. Despite its qualitative agreement with event-size statistics from nature, its
applicability is still questioned. Apart from general concerns that the DS-FFM apparently
oversimplifies the complex nature of forest dynamics, it significantly overestimates the
frequency of large fires. We present a straightforward modification of the model
rules that increases the scaling exponent α by approximately 1-3 and brings the
simulated event-size statistics close to those observed in nature. In addition, combined
simulations of both the original and the modified model predict a dependence of the
overall distribution on the ratio of lightning induced and man made fires as well
as a difference between their respective event-size statistics. The increase of the
scaling exponent with decreasing lightning probability as well as the splitting of
the partial distributions are confirmed by the analysis of the Canadian Large Fire
Database. As a consequence, lightning induced and man made forest fires cannot be
treated separately in wildfire modeling, hazard assessment and forest management. |
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