西宁市30多年来土地利用/土地覆被变化及城市扩展研究

Research on Land Use/cover Change and Urban Expansion in Xining City in Recent 30 Years

基于Landsat MSS/TM/ETM+卫星遥感影像,结合地形图、人口、社会和经济统计数据作为辅助数据,采用土地利用动态度、转移矩阵和城市扩展强度指数等方法,研究西宁市1977-2007年土地利用/土地覆被变化及城市扩展过程,以及两者的驱动机制。结果表明:①1977-2007年,耕地和林地是西宁市面积变化最大的2种土地类型;林地和城乡居住建设用地是西宁市年变化率最快的2种土地类型。②30多年来,西宁市的城市扩展可以分为2个阶段:1977-2000年的城市缓慢扩展阶段和2000-2007年的明显加速扩展阶段;东部、西部和北部是城市扩展的主要方向。③地形因素是西宁市城市空间格局扩展的基础;人口增长和经济发展是30多年来土地利用/土地覆被变化及城市扩展的主要因素;政策因素对土地利用/土地覆被变化及城市扩展有显著的推动和导向作用。

In this paper,the land use/cover change in Xining City and urban expansion as well as their driving mechanisms were analyzed using the dynamic degree,transition matrix and urban expansion intensity index based on the data of Landsat MSS/TM/ETM＋ satellite remote sensing images,topographical maps,population,society and economy.The results show that cultivated land and forestland were dominant in land use types in Xining City during the period from 1977 to 2007,and the annual change rates of forestland and land for constructing urban and rural residential areas were the highest in all land use types.In recent 30 years from 1977 to 2007,the urban expansion of Xining City could be divided into two stages,i.e.the slow expansion stage during the period from 1977 to 2000 and the rapid expansion stage during the period from 2000 to 2007.The eastern,western and northern parts of the city were the main areas of urban expansion.Topographic factors were basic for urban expansion of Xining City,population growth and economic development were the main driving factors of land use/cover change and urban expansion,and policy factors play an important role in the promotion and guidance of land uses/cover change and urban expansion.