基于Landsat8卫星影像的海南岛生态环境质量现状评价

摘要

Land use monitoring over large area and its eco-environmental quality assessment are the preconditions for land use change research based on remote sensing data.Hence,Landsat 8 operational land imager data was used to extract land use pattern and evaluate the eco-environmental quality of Hainan Island in 2015 by the decision tree classification method.The results revealed that (i) with the decision tree classification method established for Hainan Island,the overall accuracy was 86.10％ and kappa was 0.81,which meant the classification results could be used for land use analysis.(ii) Rubber plantation was mainly distributed in three counties of Hainan Province,i.e.,Danzhou,Qiongzhong and Baisha.Forest land focused in the central mountainous area and northeast part of the island.Arable land,building and bare land were mostly located in the coastal areas,and two reservoirs (Songtao and Daguangba) predominated in the water area of the island.(iii) the Synthesis evaluation model of eco-environmental quality in Hainan Island was built based on four indices,i.e.,habitat quality index (HQ),normalized difference vegetation index (NDVI),normalized difference moisture index (NDMI) and normalized difference soil index (NDSI).And the results showed that the eco-environment was good for the island but with obvious spatial difference.That is,the eco-environment quality was excellent in the central mountainous area and good in the platform rounding the mountainous area,whereas the quality was normal in the coastal areas.%利用遥感手段准确获取土地利用信息并评价其生态环境状况是土地利用/覆被变化研究的必要前提.本文基于Landsat 8陆地成像仪(OLI)多光谱影像,采用决策树分类方法提取2015年海南岛土地利用信息,分析土地利用空间分布格局,并定量评价海南岛生态环境质量现状.结果表明:(1)通过构建决策树分类模型,海南岛土地利用分类总精度达86.10％,Kappa系数为0.81,分类结果能够满足空间分析与实际应用需求. (2)林地_橡胶主要分布在海南岛中西部的儋州市、琼中县、白沙县等地;林地_其他集中在中部和南部山区以及东北部丘陵地带;耕地、建筑和裸土多处于沿海区域;水域主要有松涛水库和大广坝水库. (3)以生境质量指数HQ、归一化植被指数NDVI、归一化土壤亮度指数NDSI和归一化土壤湿度指数NDMI为输入变量,建立基于30 m×30 m格网的生态环境质量综合评价模型,结果显示目前海南岛生态环境总体状况良好,但存在明显的空间差异:中部和南部山区质量为优,山区四周台地质量良好,沿海区域质量一般.这从侧面反映了人类活动对区域生态环境质量的影响.