中文摘要：

基于国家新型城镇化与＂T＂字型发展战略理论内涵,选取长江沿岸上、中、下游中心城市重庆、武汉和南京为实证研究对象,以1980、1990、2000、2010年4期遥感影像资料为基础数据源,通过RS、GIS和景观生态结合分析,分别对其城市扩张强度、城市扩张类型和城市建设用地扩张弹性进行对比分析,并采用景观指数进行了进一步分析和验证,从而系统分析了近30a来3个城市建设用地扩张的时空特征与内在机理。结果表明：（1）30a来,南京、武汉和重庆3市城市扩张强度均呈明显上升趋势,总体呈现南京市〉武汉市〉重庆市,但2000年是一个分水岭,之后重庆市城市扩张增速赶超武汉市,南京市反而增速最低;（2）对城市扩张类型分析表明,南京市始终以边缘式增长为主;武汉市在2000年之前以飞地式扩张主导,2000年之后呈现边缘式增长;重庆市以边缘式增长为主,但2000年之后飞地式增长迅速;（3）从城市建设用地扩张弹性分析表明,1980-2010年南京市土地扩张相比城市人口开始减缓,而武汉市和重庆市在2000年以后城市扩张速度远远超过城市人口增长速度;（4）景观指数验证分析结果显示,遥感分析、地理信息分析和景观生态分析的结合能够很好反映城市建设用地的扩张过程及演化特征。

英文摘要：

Urbanization is an important social and economic phenomenon.Since the 20 th century,global urbanization has presented unprecedented scale and speed,especially in China.Spatiotemporal patterns of urban expansion,the salient features of urbanization process,have caused attention of Chinese government as well as scholars at home and abroad in different disciplines.The development mode of new-type urbanization in China is gradually changing,emphasizing the intensive and efficient development of urban lands,reflecting a change in thinking from the blind pursuit of rapid urbanization to high-quality development.According to the unbalanced regional development of China,promoting new-type urbanization needs to be suited to local conditions according to the different development characteristics of eastern,central and western regions,to allocate land resources rationally and efficiently,to realize intensive cluster development according to the timing,thus promoting urbanization transferring from land-oriented urbanization to human-oriented new-type urbanization.Existing academic research has revealed differences among the eastern,central and western regions.However,study on geographical space of urbanization process is relatively lacking.On the other hand,study on spatiotemporal urban expansion patterns has focused on the comprehensive technology integration such as Remote Sensing（RS）and Geographic Information System（GIS）in spatiotemporal analysis of built-up land expansion.To date,comparative study of urban expansion for different regions is rare,most of which has put more attention on demographic urbanization than physical urbanization.Therefore,the comparative study of urban expansion for cities of similar scale deserves more attention.Based on the content of new urbanization and the＂T＂mode development strategy,we made a comparative study of urban expansion between three central cities along the Yangtze River（i.e.,Nanjing,Wuhan and Chongqing）with RS data covering four time periods during 1980- 2010,integ