杭州城市形态和土地利用结构的时空演化

根据分形理论研究杭州1949~1996年间城市形态和土地利用结构的演化特征，发现杭州城市具有明确的自相似规律。研究表明，杭州城市形态和土地利用结构的分形性态逐渐变好，这与国外学者“演化的城市分形”观相互印证。各类土地形态的维数都小于整个城市形态的维数，从而证实了国内学者“城市化地区的分维大于各职能类土地空间分布维数”的理论推断。从时空变化来看，杭州城市形态的分维呈上升趋势，1996年接近Batty等提出的理论预期维数D = 1.71；居住用地、工业用地和对外交通用地的分维近20年来趋于增大，而教育用地和绿化用地的分维则有所减小。杭州市的分形演化和分维变化总体上揭示了城市自组织演化的特征，但工业用地维数的大幅度上升和绿化用地维数的下降显然暗示该城市在进化过程中的局部退化倾向。

Spatial-temporal Evolution of Urban Morphology and Land Use Structure in Hangzhou

The author finds that the character of self-similarity is very clear in Hangzhou when he studies the evolution of urban morphology and structure of urban land use using the theory of fractals. By dint of the box counting method, several maps of urban land use of different years are utilized to extract the basic data, and then the fractal dimensions of urban morphology and seven kinds of land are calculated. It is not difficult to find that most of the standard error σ are less than the criterion δ_c = 0.04, which was put forward by Benguigui et al. The author finds that the status of fractals of urban morphology and land use structure tend to be better with the elapse of time, which testify the viewpoint of foreign scholars about the evolving city fractals. Another important findings of the paper is that the fractal dimension of every land use is less than that of the total urban morphology, which is only a theoretical deduction before. From the viewpoint of spatial-temporal change, the fractal dimension of Hangzhou's urban morphology tends to be increasing, and in 1996 it is near D = 1.71, a mean value of fractal dimension summarized by Batty et al. As far as different urban land use of Hangzhou is concerned, the fractal dimensions of residential, industrial and external traffic land tended to be increasing from 1980 to 1996, while the fractal dimensions of education and virescence land tended to be decreasing during the same period.