南太平洋典型岛国海洋生态环境状况及其对汤加火山爆发的响应

Remote sensing research on temporal and spatial variations of ecological environments and response for Tonga volcanic eruptions in South Pacific island countries

南太平洋岛国大多四面环海且国土面积狭小,多为生态环境脆弱区。基于此,本文利用多源卫星数据,对瑙鲁、帕劳、图瓦卢、马绍尔群岛四国的海洋生态环境进行监测,基于长时间序列遥感结果的回溯,分析了其时空变化,并对比分析了汤加火山爆发前后,各国生态环境是否发生显著变化。结果显示:1)在气候态时空分布上,南太平洋岛屿国家周边海域海表温度和透明度一直维持在较高水平,叶绿素和净初级生产力则随离岸距离增加快速下降;2)升温、酸化和海平面升高是四个岛屿国家周边海域面临的共同问题;3)汤加火山的爆发对于南太平洋四岛国的沿岸悬浮物质量浓度、海表温度等无明显影响;4)火山爆发前半个月海岛地表温度以及周边海域悬浮物质量浓度异常升高的现象对利用遥感手段进行灾害预警预报具有启示作用。

The unique geographical features of the island countries in South Pacific,which are surrounded by sea and small in size,make most of the island countries in this region"ecologically fragile areas".Based on this,multi-source satellite data were used to monitor the marine ecological environment of Nauru,Palau,Tuvalu,and the Marshall Islands.It was also focused on whether there have been significant changes in the ecological environment of various countries before and after the Tonga volcanic eruption,to help to understand the impact of the Tonga volcanic eruption.The results show that:(1)In terms of temporal and spatial distribution of climatic states,the sea surface temperature and transparency of the surrounding waters of the South Pacific island countries maintain a relatively high level,while chlorophyll and net primary productivity decrease rapidly with the increase of offshore distance.(2)Warming,acidification and sea level rising are common problems faced by the sea areas of the four island countries.(3)The eruption of the Tonga Volcano has no significant impact on the coastal TSM mass concentration and SST.(4)The phenomenon of abnormally rising surface temperature and changed suspended matter mass concentration of the island in the first half month of the volcanic eruption has implications for disaster warning and forecasting using remote sensing methods.