基于元胞自动机的生物性病原物类疾病传播模型

A Cellular Automata Model for Epidemic Caused by Biological Pathogenic Organism

生物性病原物类疾病是单一植物群落中常见的一种传染病,它主要依靠风、雨和昆虫等外力传播病菌,传播过程中具有一定的潜伏性,元胞自动机是一种在时间和空间上离散,以每个个体状态的同步更新为前提来讨论系统整体性质的模型,本文利用其特点,将整个森林中的树木分为健康、潜伏期、发病期三类,以树木的营养状况和被感染时间长度为辅助变量,在考虑到树木得病后被治愈的情况后,建立了基于元胞自动机的树林生物性病原物类疾病传播模型．模拟结果表明,在不同的初始条件下,得病树所占的比例由疾病传播和被治愈的相对强度确定．疾病每次传播时,从爆发到被控制的过程具有相似的特点：随着恢复强度从小到大,初始阶段,被感染的树木迅速增加,接着进入传播速度相对缓慢的稳定过程,最终如果恢复机制足够强,则树林中的不健康树木会全部消失．

Acellular automata model has been applied to analyzing the spreading mechanism of citrus variegated chlorosis （CVC）（M.L.Martins, 2001）. In fact, CVC belongs to epidemic caused by biological pathogenic organism. CA model is suitable to analyze this kind of epidemic. The recovery mechanism of plants is considered in another article. Both infection and recovery factors are taken into account in this passage. The results of simulation indicate that under different recovery conditions, the proportion of diseased trees will be in equilibrium and it is affected by infection factor. The recovery process is very simiar to reality.