基于SDOG-ESSG的地球系统元胞自动机框架及其应用试验

元胞自动机结构简单且具备模拟复杂系统的能力,已被广泛应用于大气、流体力学、地球物理等领域。然而,现有元胞自动机以欧氏空间为约束进行地球系统过程模拟,忽略了地球重力等天然约束,导致计算过程中元胞状态的传递方向与真实运动的趋势方向不相符,一定程度上扭曲了最终的模拟结果。本文提出了地球系统元胞自动机这一概念,并从元胞表达及构建、邻居模型等方面设计了基于SDOG-ESSG格网的地球系统元胞自动机框架。由于演化规则取决于不同的应用,因此本文进一步以地壳的热传递为例,通过对热力学方程离散化设计了相应的演化规则。最后,借助公开的数据源开展了地壳热传递元胞自动机模拟的初步试验,并与一定区域下的数值模拟结果展开了比对。试验表明,与数值模拟方法相比,本文方法的模拟结果相对误差控制在27%以内,具备一定程度的可行性,可作为地球系统过程模拟的一种新思路。

The Framework of Earth System Cellular Automata Based on SDOG-ESSG and Its Preliminary Experiment

Cellular Automata (CA) has been widely adopted in atmosphere,hydrodynamics,geophysics and geoscience for its simple structure and capability of simulating complex system.Existing CAs in geoscience ignore the restraints of gravity,and do earth system processes simulation under the constraints of Euclidean,which is not in accord with the tendency of state delivery from one cell to cell,and will produce some distortions on the results.This paper is to propose an Earth System Cellular Automata (ESCA) based on the restraint of gravity.The framework,including cell representation and construction,and neighbor model based on SDOG-ESSG,was proposed in the paper.As evolution rules are highly depended on actual problems,the problem of heat conduction in the Crust was taken as an example to design an evolution rule for the ESCA by imposing a discretization on thermodynamics law.Finally,a preliminary experiment and a comparison with numerical simulation in local scale were carried out.Results showed that,ESCA is reliable to some extent with its relative error limited to 27％ comparing with numerical simulation.ESCA can be a new way of simulation for earth system process.