Scattering Properties Of Suspended Particles In High Turbid Waters And Remote Sensing Application

The scattering properties of suspended particles in the Yangtze estuarine and adjacent waters show great significance in monitoring water quality and algorithms of remote sensing. This paper mainly focused on the research of particles scattering properties based on former theory, technology and methods, and got some results which help us understand the particles scattering properties better in Yangtze River Estuarine and adjacent waters.(1) Particulate scattering and backscattering coefficient in Yangtze River estuarine shows same horizontal distribution. Data measured in near-shore waters are bigger than that of offshore. In summer, there was an obvious vertical stratification which did not happen in winter. Particulate scattering coefficient, backscattering coefficient, backscattering ratio and refraction index in winter were different from summer. In winter, particulate refraction index, phytoplankton and inorganic particulate matters contribute most to scattering and backscattering coefficient.(2) Parameterized model of backscattering coefficient in Yangtze River estuarine and adjacent waters was established based on analyses of field data. The power index n of the model decreases gradually as a power function of particulate backscattering coefficient at532nm.Relationships between backscattering coefficient and scattering coefficient were obtained in this paper and the models were named as SKLEC-SUMMER and SKLEC-WINTER. Both the two models are polynomial form. Compared with other models in same region and results, the performance of these models showed great similarities.(3) The remote sensing retrieval application of particles concentration(a) Responses of the semi-analysis retrieval models of suspended particles concentration to the variations of parameters were analyzed in this paper. Results showed that, for a certain remote sensing reflectance, assume that a*p and b*bp are constant values, high anp will overestimate the suspended particles concentration; assume that anp and b*bP are constant values, high a*p will also overestimate the suspended particles concentration; assume that a*p and anp are constant values, high b*bP will underestimate the suspended particles concentration.(b) A semi-empirical radiative transfer (SERT) model was applied to retrieve suspended sediment concentration (SSC) in Hangzhou Bay using Geostationary Ocean Color Imager (GOCI) data which have8scenes each day. A three-dimensional (3-D) unstructured-grid, free-surface, primitive equation, Finite-Volume Coastal Ocean Model (FVCOM) was applied to simulate tidal current distribution in Hangzhou Bay at the moment when GOCI overpass. Daily variation of the SSC distribution from GOCI and hydrodynamic environment from FVCOM simulation were analyzed comprehensively in this paper. Results showed that the SSC varied with tide rise and fall during a tidal cycle. Tide should be the main influence factor on the SSC distribution in the Bay. The effects of wind-driven waves contributed more to SSC distribution in winter than summer.