Journal of Tropical Oceanography ›› 2022, Vol. 41 ›› Issue (2): 65-76.doi: 10.11978/2021034CSTR: 32234.14.2021034

• Marine Remote Sensing • Previous Articles     Next Articles

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

CHEN Qiong1,2(), TANG Shilin1,3(), WU Jie1,3   

  1. 1. State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology, Chinese Academy of Sciences), Guangzhou 510301, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
  • Received:2021-03-12 Revised:2021-04-20 Online:2022-03-10 Published:2021-04-20
  • Contact: TANG Shilin E-mail:chenqiong18@mails.ucas.ac.cn;sltang@scsio.ac.cn
  • Supported by:
    National Natural Science Foundation of China(41876207);Project from Government of Guangdong Province(2019BT02H594);Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)(GML2019 ZD0302)

Abstract:

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.

Key words: Lingdingyang, GF-4, Suspended sediment concentration, Variation characteristics

CLC Number: 

  • P736.211