Towards a practical remote-sensing model of suspended sediment concentrations in turbid waters using MERIS measurements

Abstract

A new empirical index, termed the normalized suspended sediment index (NSSI), is proposed to predict total suspended sediment (TSS) concentrations in inland turbid waters using Medium Resolution Imaging Spectrometer (MERIS) full-resolution (FR) 300 m data. The algorithm is based on the normalized difference between two MERIS spectral bands, 560 and 760 nm. NSSI shows its potential in application to our study region – Poyang Lake – the largest freshwater lake in China. An exponential function (R² = 0.90, p < 0.01) accurately explained the variance in the in situ data and showed better performance for the TSS range 10–524 mg l⁻¹. The algorithm was then validated with TSS estimates using an atmospheric-corrected MERIS FR image. The validation showed that the NSSI algorithm was a more robust TSS algorithm than the band-ratio algorithms. Findings of this research imply that NSSI can be successfully used on MERIS images to obtain TSS in Poyang Lake. This work provided a practical remote-sensing approach to estimate TSS in the optically and hydrologically complex Poyang Lake and the method can be easily extended to other similar waters.

Acknowledgements

We thank the US NASA for providing MERIS data. Thanks to Dr David E. Rheinheimer for his valuables suggestions and comments on this manuscript.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant numbers 41401388 and 41331174]; the National Science & Technology Major Project (Water Major Project) [grant number 2013ZX07105-005]; the National High Technology Research and Development Programme of China [grant number 2012AA12A304]; and the Fundamental Research Funds for the Central Universities [2015904020201]