Abstract:

Cities are the center of regional systems. The simulation and prediction of urban growth is useful for regional planning, urban planning and land management.However, traditional models just regard space as an even plain, time as a simple variable. Space, time and attribute are the basic characteristics of reality world. So more effective and powerful modeling methods need to be developed to simulate the urban expansion process. Cellular Automata Mode1(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 have the ability to simulate a variety of behaviors of complex system. In order to neet the meeds of urban dynamic spatio-temporal modeling 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. Finally, to take Baotou City as an example, a model integrating GIS with ECA was built to simulate the evolution of urban expansion and sustainable land use. The initial time is 1992 when land use data were acquired by aerial photography.The change data collected by differential GPS are used for mexlel calibration. The appropriate extents of Baotou City development in 1998, 2006 and 2012 are simulated. The result of 1998 is in conformity with the surveyed data with GPS.Thus, the estaldished mexlel can be used as a virtual 1ad for decision support in urban planning and land policy-making.

Key words: cellular automata, transition rule, urban expansion, dynamic process simulation