集成GIS和细胞自动机模型进行地理时空过程模拟与预测的新方法

Integrating GIS with Cellular Automaton Model to Establish a New Approach for Spatio-temporal Process Simulation and Prediction

目前商用地理信息系统 (GIS)不能完整地表达地理实体的时态信息和时空关系 ,缺乏时空分析和时空动态模拟的能力 ,这已成为 GIS界的一个共识。然而 ,未来 GIS在各应用领域的深入发展以及在实现“数字地球”战略过程中 ,都要求发展新的时空分析和模拟方法。细胞自动机 (Cellular Automaton)是一种“自下而上”的动态模拟建模框架 ,具有模拟地理复杂系统时空演化过程的能力。首先将标准 CA模型的 4元组进行扩展以满足 GIS环境下时空动态模拟的要求 ,然后以城市土地利用演化这一动态过程为例 ,建立了土地利用演化动态模拟与预测模型 (L ESP) ,最后运用此模型对包头市城市扩展和土地可持续利用演化进行了比较成功的模拟和预测。

The functionality of spatio temporal analysis and modeling is a drive for Geographical Information Systems (GIS) to further applications in various applied fields and Digital Earth plan. However, currently commercial GIS systems lack those capabilities for spatio temporal distribution, prediction, and simulation of spatio temporal data. So more effective and powerful modeling methods need to be developed. Cellular Automaton Model (CA) provides GIS with a bottom to top spatio temporal modeling frame, which is composed of a fourfold: cells, states, neighbors and rules. The simplicity and flexibility make CA able to simulate a variety of behaviors of complex systems. In order to meet the needs of spatio temporal simulation under GIS environment, the standard CA is extended to GIS context about the concept of cells, system time and transition rules. Based on these extensions, several factors affecting urban evolution are simulated on a virtual city. Then Urban Landuse Evolution Simulation and Prediction Model (LESP) was established by integrating GIS with ECA. Finally, to take Baotou City as an example, LESP model was used to simulate Baotou City expansion process. The initial time is 1992 when land use data were acquired by aerial photography. The change data collected by differential GPS are used for model calibration. The appropriate extents of Baotou City development in 1998, 2008 and 2020 are simulated. The result of 1998 is consistent with the surveyed data with GPS. Thus, the established model can be used as a virtual lab for decision support in urban planning and land policy making.