Journal of Tropical Oceanography ›› 2019, Vol. 38 ›› Issue (3): 22-31.doi: 10.11978/2018092CSTR: 32234.14.2018092

• Marine Hydrography • Previous Articles     Next Articles

Surface suspended sediment distribution of Pearl River estuary under tropical storms with different wind and river discharge forcing

Suying OU1,2()   

  1. 1. Institute of Estuarine and Coastal Research, School of Marine Engineering and Technology, Sun Yat-sen University, Guangzhou 510275, China
    2. State-Province Joint Engineering Laboratory of Estuarine Hydraulic Technology, Guangzhou 510275, Chinas
  • Received:2018-09-10 Revised:2018-12-20 Online:2019-05-20 Published:2019-06-17
  • Contact: Suying OU E-mail:ousuying@mail.sysu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(41106015);National Key Research and Development Program of China(2016YFC0402600)

Abstract:

In this study, the data of tropical storms, CFSR gridded wind during 1949~2014, and Pearl River discharge were used to analyze wind forcing and runoff forcing on the Pearl River estuary (PRE) under tropical storm. The results show that the wind and runoff forcing varied with location and strength of the storm, and can be classified into four types: storm I with medium wind and runoff forcing on PRE, storm II with medium wind and high runoff forcing, storm III with strong wind and medium wind, and storm IV with strong wind and high runoff forcing. According to the selected moderate-resolution imaging spectroradiometer (MODIS) imaging with fine and no cloudy during tropical storms in South China, existing empirical formula between the water reflectance of MODIS band 1 and suspended sediment concentration (SSC) was used to retrieve the surface SSC in the PRE during storms, and the corresponding spatial diffusion of SSC was studied. We find that under four types of storms with different wind and runoff forcing, the responses of SSC in the PRE were different. The SSC was low under storm I, and suspended sediment diffusion was mostly controlled by tidal current. Under storm II, the higher SSC was shown in the Modaomen Estuary shoal and Lingdingyang west shoal than the other areas, which was mostly transported southwesterly. Under storm III, the distribution and diffusion of suspended sediment were influenced by the dominant storm wind, so that under strong NE wind, Lingdingyang west shoal sediment was resuspended by relatively larger waves for the largest wind fetch in the Lingdingyang estuary, higher SSC was presented and transported to the southwest under longshore current. The response of the PRE to storm IV was that the water body was muddy and the SSC was high in the whole PRE than under normal condition; and under southerly storm wind, the high SSC was diffused to the east

Key words: suspended sediment distribution, tropical storm, river discharge, wind forcing, MODIS, Pearl River estuary

CLC Number: 

  • P333.4