To Keep balance of urban land supply and demand is an important content of urban land-use planning. With the developing of economy and the population, the demand of urban land becomes larger and larger. When the urban land can't meet the need of city developing, land from rural area around the city will become the main land supply. It is called urban land expanding.Firstly, the method that the total amount of land expanded was framed according to the relations of urban land supply and demand in the paper. Secondly factors' character that how to affect the location of individual land parcel was analyzed and the character of whole spatial distributing trend of land expanded was also expounded based on it. Thirdly, a Cellular Automata (CA) model was designed to simulate the urban land expanding, in which the cell stand for the land parcels expanded and three converting rules stand for three expanding model under three different conditions, such as spatial distance, Maximum land profit and Maximum land profit with restrict of physical conditions or planning factor. Then the scheme and evaluation method of selecting a best expanding plan in all above was designed too. Lastly a Simulation Experiments that was designed to make out the expanding plan of urban land in diggings of DaTong showed the feasibility of methods in the paper.All the methods in this paper will be of great significance for city land planning. |