中文摘要：

快速城镇化发展阶段,中国正面临城市人口增长与土地扩张脱节、空城增多等诸多问题。准确识别这一过程中人口和土地城镇化的时空发展规律,对于合理规划、指导区域城镇化建设具有重要意义。以载负生态环境保护重任的湘江流域为对象,选用离差系数指标、借助GIS空间自相关模型动态评估了1990-2010年湘江流域各县级单元人口与土地城镇化水平的协调程度及时空集聚特征。结果表明,湘江流域人口和土地城镇化水平整体上均呈现上升趋势,但人口城镇化水平增速普遍较低、增长速率明显滞后于土地城镇化速率。相对于单中心的人口城镇化过程,湘江流域土地城镇化过程呈现出以长株潭城市群、娄底市、邵阳市、衡阳市为中心的多核组团圈层式发展结构。流域人口与土地城镇化过程呈现失调趋势,失调区域主要集中分布在湘江流域的＂一核四轴＂,呈显著空间聚集状态。

英文摘要：

Because of rapid urbanization,China is facing a series of problems related to the disconnection between urban population growth and land expansion,and increasingly empty cities.Accurately identifying the spatio- temporal regularity of population urbanization and land urbanization is significant for reasonable planning and regional urbanization construction in China.Here,we took the ecological protection area of the Xiangjiang Valley as our focal area. Data included total population and non-agricultural population at a country scale according to the China Statistical Yearbooks Database and 30 m spatial resolution land use data from the Geographical Information Monitoring Cloud Platform. We then used the deviation coefficient index and GIS spatial autocorrelation model to assess the coordination degree and spatio- temporal cluster characteristic of population urbanization and land urbanization at a county level from 1990 to 2010.Results demonstrated that both the level of population urbanization and land urbanization increased over the study period across the Xiangjiang Valley. The level of population urbanization showed generally low growth rates and the growth rate was obviously lower than land urbanization.Different from population urbanization of the single center mode,the progress of land urbanization of the Xiangjiang Valley clearly demonstrated multinuclear group development structure with centers at Chang-zhu-tan Urban Agglomerations,Loudi,Shaoyang and Hengyang city. The growth rate of population urbanization and land urbanization was imbalanced,and these imbalanced areas are mainly located around the‘four axes and one nuclear＇of Xiangjiang Valley with significant spatial clustering. The nuclear is Changsha- zhuzhou- xiangtan urban agglomeration and the four axes are the Beijing-Hong Kong-Macao axis,Lou-Shao-Yong axis,Tan-Lou-Shao axis and HengYong axis. The results will help optimize land development activities and provide scientific decision-making when protecting the ecological environment of the Xia