遥感监测宝鸡市城市化对土地利用的影响

Effect of urbanization on land use in Baoji City by remote sensing monitoring

目的揭示宝鸡市近几十年城市化过程对土地利用变化的影响程度。方法以西部中型城市宝鸡市为例,对该区的1991、2002及2014年Landsat卫星影像进行解译分类,提取土地利用类型面积比、土地利用动态度、城市化综合发展水平等指标,对宝鸡市的土地利用变化进行了定量分析,探讨了城市化水平与土地利用变化的关系。结果研究表明,1991-2014年宝鸡市耕地面积减少,但减幅减小,从1991-2002年的28.82%放缓到2002-2014年的16.68%;建设用地面积持续增加,且增幅增大,从1991-2002年的5.80%快速增加到2002-2014年的27.79%。城市扩张所占用的耕地和林地比重最高,且在城市边缘区变化最明显。结论宝鸡市城市化水平的高低对城市土地利用变化量有直接影响,快速城市化将导致农用地的减少和建设用地的增加。与全国城市化过程相对比,在研究年限内宝鸡市土地利用变化与城市化的关联发展未出现城市空间扩张相对稳定的时期,经历了从城市空间加速扩张阶段直接过渡到城市空间扩张和城市建设并重发展阶段。

Purposes--To reveal the impact of land use in urban district of Baoji City, Shaanxi, China in recent decades. Methods--The Landsat images of Baoji City （a middle-sized city in Western China which was selected to examine the urbanization process and land use/cover change） in 1991, 2002 and 2014 were interpreted to produce the land use maps in different periods, then such three dif- ferent factors as the area ratio of each land use type, land use dynamic degree and comprehensive de- velopment level of urbanization were extracted to analyze quantitatively the land use changes in Baoji and discuss the relationship between urbanization level and land use changes. Results--The research showed that the area of cropland decreased by 28.82% from 1991 to 2002 which is faster than the de- cease of 16.68% from 2002 to 2014. Meanwhile, the area of land used for urban construction continu- ously increased, from 5.80% during the period of 1991 to 2002 to 27.79% during the period of 2002 to 2014. The proportion of arable land and woodland which are occupied by urban sprawl is the high- est, and the changes are the most obvious in the urban fringe. Conclusions--The urbanization level of Baoji City has direct impact on the changes in the amount of urban land-use. Rapid urbanization of Baoji City has happened in last decades, which resulted in the decrease in farmland and the increase in construction land. Compared with the national urbanization process, Baoji City also experienced the development stage from rapid urban spatial expansion period to the period in which equal importance was attached to the urhan spatial expansion and urhan construction, hut the relatively stable period of urban expansion didn＇t appear