山地城市扩展及生态变化遥感分析

Analysis of Urban Expansion and Ecological Changes Based on Remote Sensing Imagery in Mountainous City

城市化进程使植被和水体等生态资源用地日渐缩小和破碎。遥感技术由于具有宏观、快速、准确认知对象的优势在城市生态环境变化监测中发挥着日益重要的作用。本研究采用Landsat系列遥感数据,选择EIBI建筑指数提取城市建筑用地扩展信息,并运用遥感生态指数(RSEI)对龙岩市生态质量变化进行遥感评估。结果表明:1)增强的指数型建筑指数(EIBI)可有效抑制裸土信息,增强建筑用地信息,使用EIBI提取建筑用地的精度可达90%以上;2)2002—2014年为龙岩市快速发展期,建成区面积增幅达50%;生态退化面积大大超过生态改善面积;整体生态指数均值自0.684降至0.636,降幅达7.02%,建成区生态指数均值自0.370降至0.351;3)造成龙岩市生态质量退化的主要因素包括:一是城市建筑用地扩展,二是采矿工程建设和地表开挖工程建设。

With rapid urbanization, the area of ecological land use, such as water body and vegetation, decrease and landscape fragmentation increase. Being macroscopical, precise and dynamical, remote sensing＇s application in monitoring urban ecological environment is more and more important. In this research, the chosen test area for data collection is located in the city of Longyan, and the Landsat series data were employed to analyze the urban expansion and ecological changes in the mountainous city. Enhanced Index-based Built-up Index （EIBI） was used to extract the information of urban growth, and Remote Sensing Ecology Index （RSEI） was performed to evaluate the ecology quality. The experimental results show that EIBI effectively suppresses the information of bare soil and en- hances the information of building. The accuracy of the building extraction reached 90% using the EIBI. In addition, Longyan city was in rapid development period of the urbanization from 2002 to 2014. The total RSEI of the Longyan city declined to 0. 636 in 2014 from 0. 684 in 2002, with a 7.02 % drop. The mean of RSEI in built-up area felled to 0. 352 in 2014 from 0.37 in 2002. It is concluded that the driving force for the environmental degeneration mainly includes expansion of urban building areas and development of mining.