基于遥感生态指数的杭州湾大湾区生态质量演化监测及其对土地利用响应分析

Dynamic Monitoring of Ecological Quality for Hangzhou Greater Bay Area and Its Response to Land Use Cover Change Using Remote Sensing based Ecological Index

生态质量监测与评价是合理、高效开展生态环境保护工作的基础和关键。通过构建遥感生态指数(RSEI)监测了杭州湾大湾区1995~2020年生态质量时空变化,通过耦合土地利用/覆被变化挖掘了生态质量变化和土地利用类型/转化间的定量关系。结果表明:①杭州湾大湾区整体生态质量呈现上升下降再上升的变化过程,RSEI维持在0.62,生态质量较为优良;各地级市生态质量变化迥异,由北向南依次呈现下降、上升和波动3种不同趋势。②杭州湾大湾区生态质量上升区域(57.5%)多于下降区域(42.5%),山区林地、中心城区和滨海湿地是生态质量上升的热点区域,而城镇化和滩涂围垦则是生态质量下降的主要原因。③近25 a森林和建设用地的生态质量快速上升(ΔRSEI>+0.1),耕地生态质量明显下降(ΔRSEI=-0.08),导致人类环境内部的生态质量差异逐步减小,而自然向人类环境转化的生态代价日益增大。研究可为海岸带资源合理利用和生态环境保护提供科学依据,服务湾区城市群社会高质量发展。

Ecological quality monitoring and evaluation is the basis and key to carrying out ecological and environmental protection work reasonably and efficiently.Ecological quality monitoring is the basis and key process for effective ecological conservations,and it also plays an important role in ecological civilization and high quality development of our society.In this study,we constructed a Remote Sensing based Ecological Index(RSEI)to monitor the spatio-temporal changes of ecological quality in the Hangzhou Greater Bay Area during 1995-2020.On the basis of which,we explored the quantitative relationship between ecological quality and land use types or conversions by coupling RSEI and land use data.The results showed that,(1)the overall ecological quality of Hangzhou Greater Bay Area first increased,then decreased,followed by an increase at the end.The RSEI maintained at 0.62,indicating that a relatively good ecological quality.The ecological quality of its belonging prefecture-level cities exhibited three different trends:decline,rise and fluctuation from north to south.(2)The area with improved ecological quality(57.5%)was greater than the one with degraded ecological quality(42.5%)in the Hangzhou Greater Bay Area.The forests,central urban areas and coastal wetlands were the hotspots for ecological quality imporvement,while the processes of rapid urbanization and tidal flat reclamation were responsible for degraded ecological environments.(3)In recent 25 years,the ecological quality of forest and build-up areas increased rapidly(△RSEI>+0.1),but the ecological quality of cultivated land decreased significantly(△RSEI=-0.08).This migrated the gap of ecological quality within human dominant environments,meanwile increased the ecological cost of the transformation from nature to human dominant environments.The study is expected to provide scientific basis for balancing coastal resource developments and ecological conservations,and serve for the high-quality development of coastal urban agglomerations.