不透水面提取在玉溪市城市扩展分析中的应用

Application of Impervious Surface Extraction in Urban Expansion Analysis of Yuxi City

采用Landsat5-8影像,以NDVI以及MNDWI作为辅助的不透水面提取指标,对玉溪市红塔区、玉溪市江川区2000、2005、2010、2015年通过目视解译进行城区范围界定,精度检验Kappa系数为75.74%。对比玉溪市这2个市辖区15 a间城市扩展强度、城市扩展速率的变化。结论表明红塔区在2000-2015年4个阶段的城区扩展速率都大于江川区,并在2010-2015年达到城市扩展速率顶峰,为2.18 km^2/年。相应地,城市扩展速率快的期间,城市扩展强度大。最后,采用城市扩展象限法对2个研究区域的城市扩展进行方向分异分析、城市扩展形态分析。研究结论可为玉溪市城市扩展和城市规划提供数据支撑,研究思路可作为中国西部乃至山地城市扩展理论和技术基础。

We used Landsat5-8 remote sensing images and the impervious surface extraction factors aided by NDVI and MNDWI to define the urban scope of Hongta District and Jiangchuan District of Yuxi City in 2000,2005,2010 and 2015 with visual interpretation.The Kappa coefficient reached to 75.74%.Then,we compared the urban expansion intensity and urban expansion rate of the two districts of Yuxi City.The results indicated that from 2000 to 2015,the urban expansion rate of Hongta District was larger than Jiangchuan District at all times,and Hongta District reached the largest urban expansion rate from 2010 to 2015,2.18 km2/a.Meanwhile,urban expansion intensity showed the same trend with urban expansion rate,in other words,when the city had large urban expansion rate,the urban expansion intensity was large.Finally,we adopted the urban expansion quadrant method to analyze the directional difference and urban expansion morphology.The results of this research can provide data support for urban expansion and urban planning in Yuxi City,and the research ideas can be served as the theoretical and technical basis for the expansion of Western and mountainous cities in China.