Journal of Marine Sciences ›› 2022, Vol. 40 ›› Issue (1): 64-71.DOI: 10.3969/j.issn.1001-909X.2022.01.007

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Study on spectral curve characteristics of surface  suspended sediment concentration in the Changjiang (Yangtze River) Estuary based on hyperspectral sensor#br#

 Suspended sediment concentration (SSC) is one of the important water quality parameters in estuarine water research. Remote sensing determination of SSC is an important method. In order to study the quantitative gradient relationship between remote sensing spectral data and surface suspended sediment concentration(SSSC), the surface sediments near the Nanhuizui of the Changjiang (Yangtze River) Estuary were collected, the gradient changes of SSSC were designed quantitatively, and the optical characteristics of sediment laden water with different concentrations were measured by ASD hyperspectral spectrometer. The results show that with the increase of SSSC, the spectral reflectance curve of water has similar morphology, but there are also some differences. When SSSC<36.59 mg/L, the spectral curve has only one reflection peak at 560-580 nm. When SSSC>52.69 mg/L, the first reflection peak of the spectral curve is at 570-710 nm, and the second reflection peak appears at 780-820 nm in the near infrared band. There is an obvious “red shift” phenomenon in the first peak interval of the spectral curve, and the linear fitting R2 between the “red shift” change of wavelength and SSSC reaches 0.91, indicating a strong linear correlation between them. In the spectral range of 400~900 nm, 600-860 nm band is sensitive and stable to the change of SSSC in the range of 0~200 mg/L, and 740900 nm band has stronger response to the change of SSSC>200 mg/L.   

  1. 1.College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China; 

    2.Marine Monitoring and Forecasting Center of Shanghai, Shanghai 200333, China; 

    3.Shanghai Engineering Research Center of Estuarine and Oceanographic Mapping, Shanghai 201306, China
  • Online:2022-03-15 Published:2022-03-15

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Abstract:  Suspended sediment concentration (SSC) is one of the important water quality parameters in estuarine water research. Remote sensing determination of SSC is an important method. In order to study the quantitative gradient relationship between remote sensing spectral data and surface suspended sediment concentration(SSSC), the surface sediments near the Nanhuizui of the Changjiang (Yangtze River) Estuary were collected, the gradient changes of SSSC were designed quantitatively, and the optical characteristics of sediment laden water with different concentrations were measured by ASD hyperspectral spectrometer. The results show that with the increase of SSSC, the spectral reflectance curve of water has similar morphology, but there are also some differences. When SSSC<36.59 mg/L, the spectral curve has only one reflection peak at 560-580 nm. When SSSC>52.69 mg/L, the first reflection peak of the spectral curve is at 570-710 nm, and the second reflection peak appears at 780-820 nm in the near infrared band. There is an obvious “red shift” phenomenon in the first peak interval of the spectral curve, and the linear fitting R2 between the “red shift” change of wavelength and SSSC reaches 0.91, indicating a strong linear correlation between them. In the spectral range of 400~900 nm, 600-860 nm band is sensitive and stable to the change of SSSC in the range of 0~200 mg/L, and 740900 nm band has stronger response to the change of SSSC>200 mg/L.


Key words: Changjiang (Yangtze River) Estuary, suspended sediment concentration, hyperspectral, gradient change, remote sensing

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