基于遥感生态指数的近35年城市地表生态环境质量变化评价——以杭州市余杭区为例
Evaluation of Urban Surface Ecological Environment Quality Changes over the Past 35 Years Based on Remote Sensing Ecological Index—A Case Study of Yuhang District, Hangzhou City

自21世纪初以来，随着我国城市化步伐的加快，早期在城市发展过程中对生态环境保护的忽视导致了一些负面效应。然而，近期国家对生态文明建设的重视程度显著提升，这对提升城市生态环境质量产生积极影响。为了科学地评价我国城市生态文明建设的成效，对城市生态环境质量进行评估变得尤为重要。本文以1987年、2004年和2022年Landsat系列遥感影像为基础数据源，提取反映生态环境质量的绿度(NVDI)、湿度(WET)、热度(LST)和干度(NDBSI)四个指标，通过计算遥感生态指数(RSEI)对杭州市余杭区近35年内的城市生态环境质量进行评估。结果显示，余杭区在1987至2022年，生态环境质量经历了先逐渐变差再逐渐转好的过程。1987、2004、2022年RSEI平均值分别为0.802、0.765、0.735。1987到2022年研究区变差面积为295.2 km²，占总面积的31.78%；不变的面积为447.65 km²，占总面积的47.28%；变好的总面积为203.92 km²，占总面积的21.53%。研究区变差的区域主要是仁和、良渚、勾庄、未来科技城等；变好的区域是径山、余杭、中泰、闲林等。总的来说，余杭区城市生态环境质量先是变差，近些年来正在逐渐改善。
Since the beginning of the 21st century, with the accelerated pace of urbanization in China, the initial neglect of ecological environment protection in the process of urban development has led to some negative effects. However, in recent years, the level of attention paid by the country to ecological civilization construction has significantly increased, which has a positive impact on improving the quality of urban ecological environment. It is particularly important to scientifically evaluate the effectiveness of China’s urban ecological civilization construction by assessing the quality of urban ecological environment. In this study, based on Landsat series remote sensing images from 1987, 2004, and 2022, we extracted four indicators reflecting the quality of ecological environment: Normalized Vegetation Difference Index (NVDI), Wetness (WET), Land Surface Temperature (LST), and Normalized Difference Built-up Index (NDBSI). By calculating the Remote Sensing Ecological Index (RSEI), we evaluated the quality of urban ecological environment in Yuhang District of Hangzhou City over the past 35 years. The results showed that the ecological environment quality in Yuhang District underwent a process of gradual deterioration followed by gradual improvement from 1987 to 2022. The average values of RSEI in 1987, 2004, and 2022 were 0.802, 0.765, and 0.735 respectively. From 1987 to 2022, the area of deterioration in the study area was 295.2 km², accounting for 31.78% of the total area; the unchanged area was 447.65 km², accounting for 47.28% of the total area; and the improved area was 203.92 km², accounting for 21.53% of the total area. The deteriorated areas in the study area were mainly Renhe, Liangzhu, Gouzhuang, and Future Science and Technology City, while the improved areas were Jingshan, Yuhang, Zhongtai, and Xianlin. Overall, the quality