对2000年、2005年及2010年的遥感影像图进行解译,得到3个时期的土地利用分类图,运用景观指数法和空间分析法等方法,对长株潭地区聚落的空间演化特征及动因进行分析,并分析了聚落与耕地之间的空间关系。结果表明:长株潭地区聚落的面积、数量规模和分布密度加速扩大,集中分布在高程200 m以下;聚落空间演化的自然动因是低地平原指向,而社会动因是人口规模的变化;提出耕地与聚落面积比指数(K)概念,根据K值的大小可以将耕地与聚落的空间组合关系分为3类地区:耕地资源紧缺区、耕地资源平衡区、耕地资源盈余区;聚落与耕地的空间转移关系可以分为两大类:持续稳定型和动态变化型;长沙市周边耕地转为聚落的趋势十分明显;聚落空间扩张对耕地的影响存在一个空间临界点,城市化速度越快,临界点的位置距离聚落越远。

Land use map in Chang-Zhu-Tan region was obtained from remote images in 2000, 2005 and 2010. Spatial evolution characteristics of settlements in Chang-Zhu-Tan and their impact factors were analyzed from the perspectives of landscape index, horizontal space and the vertical space, with the support of Arc GIS10.0 & Fragstats4.0 software. Methods involved were landscape index method and spatial analysis.The spatial relationship between the settlement and arable land was also investigated from three aspects such as space combination, space shift and space distance. The results showed that: the area, number and distribution density of the settlements in Chang-Zhu-Tan region, which were mainly located in the area below 200 m,was enlarging faster than before. The distribution density of urban settlements is small and their shape are in good orders,while the distribution density of the rural is higher but with disorderly structures.The natural trend of settlement spatial evolution is to lowland plains, whose social factors are population changes. We also put forward a concept in the paper, area ratio index (K) of land to settlements. According to the K value, the spatial combination of the arable land and settlements can be classified into three kinds: areas with a shortage of arable land resource, areas with co-ordination of supply and demand in arable land resource and areas with surplus in arable land resource. The space-transfer relationship between settlements and arable land could be divided into two types: areas without changes and areas with dynamic changes. The changes from arable land into settlements were obviously observed in regions around Changsha city. The faster the urbanization is, the farther the distance between the critical point and settlements is.