中文摘要：

本文以不透水面为基础，采用面向对象的方法对城市建成区进行提取，并有效地划分城市内各组份的归属，突破以往依据行政界线划分城市建成区的观念，之后应用引力模型，对提取的城市建成区进行等级划分与动力机制分析，便于快速掌握城市发展重心、了解城市发展方向，为城市规划和管理提供依据。实验表明，以不透水面为标志提取的范围，基本能够正确表达城市建成区范围；用引力模型求取的城市主建成区范围基本与实际城市中心范围相吻合。

英文摘要：

This paper extracted the urban built-up area based on the impervious surface through obiect- oriented method, and according to a series of related urban planning standards made a set of build-up area definition scheme quantitatively through analysis and calculation to divide the belongings of components in the city effectively, which broke the idea that the urban built-up area was divided by administrative bound- ary as before. Then it used the gravity model to calculate the gravity between areas, and to do the grade division and dynamic mechanism analysis of the extracted urban built-up area in order to investigate the center of gravity and the direction of urban development, which would provide evidence for urban planning and management. Through the experiment, it was proved that the range extracted based on the impervious surface could express the urban built-up area range correctly; the range of urban main built-up area calcu- lated by gravity model would be identical with the actual urban center.