中文摘要：

研究城市空间扩张的形态特征和动力机制对解决城市化问题具有重要意义.以福建东部海岛型城镇平潭县为例,借助遥感和GIS技术方法,通过提取主城区城镇用地遥感信息,探讨平潭县主城区城镇扩张的空间特征和驱动机理.结果表明,平潭县主城区城镇用地在东部和南部方向扩张明显,西北方向增长较为缓慢,城镇重心向东南方向偏移;建设用地紧凑度指数变大,城镇扩张呈现良性态势,未来将形成趋于圆形的城市发展格局;平潭县城镇扩张是自然、经济、社会诸多因素综合作用的结果.

英文摘要：

Research on morphological characteristics and dynamic mechanism of urban expansion is vital to solve urbanization problems. This article took Pingtan county,an island-town located on the eastern seashore of Fujian province,as the study area. By extracting construction land information in Pingtan county, the morphological characteristics of the main urban area spatial expansion were summarized and the driving mechanism of urban land growth was investigated,using remote sensing and GIS comprehensively. The resuits showed that urban land spatial expansion of Pingtan county was quite distinct,mainly concentrated in eastern and southern parts, while the growth in northwest area was relatively slow. The county center shif- ted along the southeast direction. The compact index of construction land in the main urban district increased,which showed a healthy development momentum,and it gradually formed a similarly round pattern of urban development. The urban spatial expansion was a result of integrated natural, economic and social factors.