基于GEE平台的舟山岛生态环境质量动态评价

Dynamic Evaluation of Ecological Environmental Quality of Zhoushan Island Using Google Earth Engine

[目的]对舟山岛2000—2020年的生态环境变化进行动态监测和评价,为类似海岛地区的生态环境质量评价提供科学参考。[方法]以舟山岛为研究对象,在GEE(Google Earth Engine)平台选取2000,2005,2010,2015和2020年5期的遥感影像,提取出湿度(WET)、绿度(NDVI)、热度(LST)、干度(NDBSI)4个指标进行耦合,得到遥感生态指数(remote sensing environmental index,RSEI),利用主成分分析方法对舟山岛生态环境质量变化进行评价。[结果]①在5个时间节点上,舟山岛RSEI均值分别为0.6312,0.6375,0.6116,0.5503和0.5024。在研究期间内,舟山岛的RSEI共下降了20.41%;②舟山岛生态环境质量呈下降趋势,岛屿生态质量为优和良的面积分别下降了12.51%和11.87%,生态质量为差、较差和中的面积分别上升了7.35%,12.49%和4.55%;③研究期间内舟山岛人类开发活动明显增强,土地利用类型发生改变,气候变化和人类活动共同作用于舟山岛,导致生态环境变差。[结论]利用遥感生态指数对于海岛生态环境质量同样可进行有效的监测与评价。在研究期间内舟山岛生态环境质量前期较稳定,后期降幅较明显,研究期间内总共下降约20.41%。

[Objective]The ecological environmental changes of Zhoushan Island from 2000 to 2020 were dynamically monitored and evaluated in order o provide a scientific reference for the evaluation of the ecological quality of similar island areas.[Methods]Remote sensing images of Zhoushan Island in 2000,2005,2010,2015,and 2020 were selected on the Google Earth Engine(GEE)platform.Wetness,greenness,heat,and dryness were extracted for coupling,and the remote sensing environmental index(RSEI)was obtained.The principal component analysis method was then used to evaluate changes in the quality of the ecological environment of Zhoushan Island.[Results]①The mean values of RSEI on Zhoushan Island at the five time points were 0.6312,0.6375,0.6116,0.5503,and 0.5024,respectively,with a total decrease of 20.41%over the study period.②The ecological quality of Zhoushan Island exhibited a downward trend over time,with the area of the island having excellent and good ecological quality decreasing by 24.39%,and the area with poor and poorer quality increasing by 19.82%.③During the study period,human development activities on Zhoushan Island have increased significantly,land use types have changed,and climate change and human activities have combined to degrade the ecological environment of Zhoushan Island.[Conclusion]RSEI was effectively used to monitor and evaluate the ecological environmental quality of the island.The ecological environmental quality of Zhoushan Island was relatively stable during the early part of the study period,but there was an obvious decline in environmental quality during the later part of the study period,with a total decrease of about 20.41%during the study period.