A semi-phenomenological approach to explain the event-size distribution of the Drossel-Schwabl forest-fire model

We present a novel approach to explain the complex scaling behavior of the Drossel-Schwabl forest-fire model in two dimensions. Clusters of trees are characterized by their size and perimeter only, whereas spatial correlations are neglected. Coalescence of clusters is restricted to clusters of simil...

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Bibliographic Details
Main Authors: S. Hergarten, R. Krenn
Format: Article
Language:English
Published: Copernicus Publications 2011-06-01
Series:Nonlinear Processes in Geophysics
Online Access:http://www.nonlin-processes-geophys.net/18/381/2011/npg-18-381-2011.pdf
Description
Summary:We present a novel approach to explain the complex scaling behavior of the Drossel-Schwabl forest-fire model in two dimensions. Clusters of trees are characterized by their size and perimeter only, whereas spatial correlations are neglected. Coalescence of clusters is restricted to clusters of similar sizes. Our approach derives the value of the scaling exponent <i>τ</i> of the event size distribution directly from the scaling of the accessible perimeter of percolation clusters. We obtain <i>τ</i> = 1.19 in the limit of infinite growth rate, in perfect agreement with numerical results. Furthermore, our approach predicts the unusual transition from a power law to an exponential decay even quantitatively, while the exponential decay at large event sizes itself is reproduced only qualitatively.
ISSN:1023-5809
1607-7946