 |
| Titel |
Cellular automaton modelling of lightning-induced and man made forest fires |
| VerfasserIn |
R. Krenn, S. Hergarten |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 9, no. 5 ; Nr. 9, no. 5 (2009-10-30), S.1743-1748 |
| Datensatznummer |
250006995
|
| Publikation (Nr.) |
 copernicus.org/nhess-9-1743-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| The impact of forest fires on nature and civilisation is conflicting: on one
hand, they play an irreplaceable role in the natural regeneration process,
but on the other hand, they come within the major natural hazards in many
regions. Their frequency-area distributions show power-law behaviour with
scaling exponents α in a quite narrow range, relating wildfire
research to the theoretical framework of self-organised criticality. Examples
of self-organised critical behaviour can be found in computer simulations of
simple cellular automaton models. The established self-organised critical
Drossel-Schwabl forest fire model 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 Drossel-Schwabl model apparently oversimplifies the complex
nature of forest dynamics, it significantly overestimates the frequency of
large fires. We present a modification of the model rules that distinguishes
between lightning-induced and man made forest fires and enables a systematic
increase of the scaling exponent α by approximately 1/3. In addition,
combined simulations using both the original and the modified model rules
predict a dependence of the overall event-size distribution on the ratio of
lightning induced and man made fires as well as a splitting of their partial
distributions. Lightning is identified as the dominant mechanism in the
regime of the largest fires. The results are confirmed by the analysis of the
Canadian Large Fire Database and suggest that lightning-induced and man made
forest fires cannot be treated separately in wildfire modelling, hazard
assessment and forest management. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|