基于GF-4卫星反演的珠江口水体表层悬浮泥沙时空变化特征  

Spatial-temporal variation of suspended sediment in the Pearl River Estuary retrieved from GF-4 satellite data

作　　者：陈琼 唐世林[1,3] 吴颉 CHEN Qiong;TANG Shilin;WU Jie(State Key Laboratory of Tropical Oceanography(South China Sea Institute of Oceanology,Chinese Academy of Sciences),Guangzhou 510301,China;University of Chinese Academy of Sciences,Beijing 100049,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China)

机构地区：[1]热带海洋环境国家重点实验室(中国科学院南海海洋研究所),广东广州510301 [2]中国科学院大学,北京100049 [3]南方海洋科学与工程广东省实验室(广州),广东广州511458

出　　处：《热带海洋学报》2022年第2期65-76,共12页Journal of Tropical Oceanography

基　　金：国家自然科学基金(41876207);广东省重大团队项目(2019BT02H594);南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0302)。

摘　　要：珠江口伶仃洋是中国重要的海湾之一,其水体的悬浮泥沙质量浓度(suspended sediment concentration, SSC)在枯季受潮汐过程影响显著,是研究潮汐对SSC变化影响的理想区域。高分四号卫星(GF-4)是我国第一颗超高时空分辨率地球同步轨道卫星,可见光波段的空间分辨率为50m,最大时间分辨率可达20s,在研究一日之内的SSC变化特征方面具有独特的优势。文章利用过境珠江口伶仃洋的GF-4卫星L1A数据并结合2020年1月的航次数据,反演得到该海域表层SSC数据,分析得到了伶仃洋表层SSC在潮汐周期不同阶段的分布特征及变化规律。研究结果表明,伶仃洋海域的SSC整体呈近岸高于远岸、西岸高于东岸的分布趋势。涨潮时,共有4个高SSC分布区,平均SSC呈降低趋势且悬沙有向湾内移动的趋势;在停潮末—涨急—涨憩过程中, SSC先略微降低后显著降低。落潮时,共有7个高SSC分布区,平均SSC呈增长趋势且悬浮泥沙有向外海方向移动的趋势;在平潮末—落急—落憩过程中, SSC先显著增大再变缓最后呈负增长趋势。SSC变化受水平方向上的挟沙作用、垂直方向上的再悬浮过程和地形的共同影响。Lingdingyang of the Pearl River Estuary is one of the most important bays in China. The suspended sediment concentration(SSC) there is significantly affected by the tidal processes in the dry season, which makes it an ideal area for studying the influence of tides on SSC variation. The Gaofen-4(GF-4) satellite is the first geosynchronous orbit satellite with ultra-high spatial and temporal resolution in China. The spatial resolution of visible light bands is 50 m, and the maximum temporal resolution can reach 20 s. It has unique advantages in studying the variation of SSC within one day. In this study, we retrieved the surface SSC of Lingdingyang from the GF-4 satellite L1A data and in-situ data in January 2020, and then analyzed the spatial distribution of SSC in different stages of a tidal cycle. The results showed that the SSC in Lingdingyang was higher nearshore than offshore, and higher in the west than in the east. At flood tide, there were four high SSC areas. The average SSC showed a decreasing trend, and the suspended sediment was transported to the bay. During the initial, middle and last stages of flood tide, the decreased SSC became gradually more significant. At ebb tide, there were seven high SSC areas.The average SSC showed an increasing trend, and the suspended sediment moved toward the sea. During the initial, middle and last stages of ebb tide, the SSC increased significantly first, and then slowed down;it finally showed a negative growth trend. The variation of SSC was jointly affected by sediment transport in the horizontal direction, resuspension process in the vertical direction, and topography.

关 键 词：珠江口伶仃洋 高分四号卫星 悬浮泥沙质量浓度 变化特征 

分 类 号：P736.211[天文地球—海洋地质]