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Forest-fire Model
In applied mathematics, a forest-fire model is any of a number of dynamical systems displaying self-organized criticality. Note, however, that according to Pruessner et al. (2002, 2004) the forest-fire model does not behave critically on very large, i.e. physically relevant scales. Early versions go back to Henley (1989) and Drossel and Schwabl (1992). The model is defined as a cellular automaton on a grid with ''L''''d'' cells. ''L'' is the sidelength of the grid and ''d'' is its dimension. A cell can be empty, occupied by a tree, or burning. The model of Drossel and Schwabl (1992) is defined by four rules which are executed simultaneously: # A burning cell turns into an empty cell # A tree will burn if at least one neighbor is burning # A tree ignites with probability ''f'' even if no neighbor is burning # An empty space fills with a tree with probability ''p'' The controlling parameter of the model is ''p''/''f'' which gives the average number of trees planted between tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Fire Model
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban use." Using this definition, '' Global Forest Resources Assessment 2020'' (FRA 2020) found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the predominant terrestrial ecosystem of Earth, and are found around the globe. More than half of the world's forests are found in only five countries (Brazil, Canada, China, Russia, and the United States). The largest share of forests (45 percent) are i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
