高分卫星在甘肃省城镇扩展研究中的应用

Application of High Resolution Satellite Data in the Study of Urban Expansion in Gansu Province

遥感和地理信息相结合是实现对变化快速、空间分布范围广的城镇扩展进行实时、准确监测的最佳手段之一。获取城镇扩展的基础数据,把握城镇扩展的空间分异特征及城镇体系结构特征,揭示城镇扩展与耕地保护之间矛盾有助于政府管理部门做出正确的决策。以高分卫星影像为主要数据源,结合土地利用数据对甘肃省87个主要城(市)镇2008~2014年城镇扩展进行监测,对监测结果进行分析。结果表明:甘肃省城镇化发展较快,城(市)镇扩展面积达232.01km^2,扩展强度为25.3%;城镇扩展空间分异大,位于河西绿洲区、兰白城镇带以及陇东能源基地的经济基础好,交通要道沿线的城(市)镇发展迅速,而在甘南山地和祁连山高山地区的城镇规模小,发展落后;城镇体系结构不协调,城镇体系呈二元结构,整体发展水平较低;46.95%的城镇扩展用地源自耕地,耕地保护压力大,提高城镇建设用地节约集约利用水平是协调城镇发展和耕地保护矛盾的有效途径。

The urban expansion changes rapidly and is widely distributed.Combinating remote sensing and GIS is the best way to monitor the urban expansion in real-time and accurately.It will help the government to make right decision by obtaining the basic data of urban expansion,grasping the urban system structure characteristics of urban expansion and revealing the contradiction between urban expansion and protection of arable land.In this research,the high resolution satellite data and the land-use changing investigation data were used to monitor the urban expansion of 87 counties in Gansu from 2008 to 2014.The monitoring results were analyzed thoroughly.It show that Gansu is at the stage of rapid urbanization,the area of those 87 cities and towns increased 232.01km^2,and its expansion intensity is 25.3%.Spatial differentiation of the urban expansion is large.Cities in the Hexi oasis,the Lanzhou-Baiyin city belt and the energy base in eastern Gansu where the traffic is developed and the economic basis is good.However,the cities in the mountainous area of southern Gansu and the Qilian Mountains are small,they also developed slowly.The structure of the urban system of Gansu is uncoordinated due to the dual structure of the urban system.The urbanization degree is low in Gansu.46.95% of the land occupied by urbanization is arable land,and the pressure to protect arable land is high.Improving the level of intensive use of construction land is an effective way to solve the contradiction between urbanization and arable land protection.