基于遥感生态指数的南京市浦口区生态环境质量时空变化分析
Analysis on the Temporal and Spatial Changes of Ecological Environment Qualityin Pukou District of Nanjing Based on Remote Sensing Ecological Index

本文以2013年5月和2018年7月的Landsat8 OLI/TIRS影像，对南京市浦口区生态环境质量进行了监测与分析。从影响生态环境的因素出发，选取了能较好表征生态环境质量的四个指标，分别用湿度指数(WET)、归一化植被指数(NDVI)、地表温度(LST)、裸土指数(NDSI)来表征每一个指标，并利用主成分变换(PCA)确定各项指标的权重。同时，将计算得出的遥感生态指数(RSEI)分成优、良、中、较差和差五个等级，对浦口区的生态环境质量变化进行时空变化分析。结果表明：① 湿度、绿度指标均对浦口区的生态环境质量起到积极促进作用，而干度和热度指标对生态环境质量均起到负面作用，且四个指标中植被对生态环境质量影响最大；② 浦口区2013年、2018年遥感生态指数的均值分别为0.578，0.622；③ 2013年至2018年期间，RSEI等级变差、不变和变好的面积比例分别为15.0%，49.4%，35.6%，浦口区生态环境治理总体呈现上升趋势，说明近五年浦口区城市化发展过程中生态环境得到了很好的保护；④ 大部分区域生态环境质量仍然保持原状，并没有发生明显的变化，盘城镇有明显的生态环境质量变差的现象，而长江沿岸的区域生态环境质量得到了些许的改善。
Based on Landsat 8 OLI images in May 2013 and July 2018, this paper monitored and analyzed the ecological environment quality of Pukou District, Nanjing. Based on the factors affecting the eco-logical environment, four indicators were selected to better characterize the ecological environment quality. Wet index (WET), Normalized Vegetation Index (NDVI), Land Surface Temperature (LST), Bare Soil Index (NDSI) were used to characterize each index, and the weight of each index was determined by Principal Component Transform (PCA). At the same time, the calculated ecological environment quality is divided into five grades: excellent, good, medium, poor and poor. The dynamic monitoring and analysis of the changes of ecological environment quality in Pukou District are carried out. The results showed that: 1) Humidity and greenness indices had positive effects on the ecological environment quality of Pukou District, while dryness and heat indices had negative effects on the ecological environment quality, and vegetation had the greatest impact on the ecological environment quality of the four indices; 2) The average values of remote sensing ecological indices in Pukou District in 2013 and 2018 were 0.578, 0.622, respectively; 3) From 2013 to 2018, the proportion of RSEI grade variation, invariance and improvement was 15.002%, 49.386% and 35.612% respectively. The overall trend of ecological environment management in Pukou District is on the rise, which indicates that the ecological environment has been well protected in the process of urbanization development in Pukou District in the past five years; 4) Most of the regional ecological environment quality remains unchanged, and no obvious changes have taken place. Pancheng Town has obvious deterioration of the ecological environment quality, while the regional ecological environment quality along the Yangtze River has been slightly improved.