South Yellow Sea Coastal Waters Of Suspended Sediment Analysis And Remote Sensing

Most of high turbid water distributes near the shore and estuary. The retrieval of its suspended particle concentration (SPC) is useful, but its optical property is unstable because of its complicated components, so the suitable model is in research. Based on the in-situ measured suspended particle concentration, grain size and spectral data, this thesis investigates the variation characters of three factors. The retrieval models of the surface SPC are established, after analyzing the correlation between the SPC and the reflectance. According to the influence of the grain size, the retrieval model of SPC excluding the grain size factor is built at last. The main tasks and conclusions include:(1)Numerous SPC, grain size and spectral measurements were carried out in Xiao Yangkou, located in the South Yellow Sea. This offers synchronous and successive data for the later factors analysis and model building.(2) Comparing the grain size measurement results of the Master Size 2000 and Lisst, it is concluded that the processing methods of the samples affects the grain size data. In-situ measurement data should be adopted when the relation between the grain size in nature water and the reflectance is analyzed, that can ensure the accuracy of the results.(3) The grain size of the surface suspended particles is dominated by silt and clay, after analyzing the variation trend of the surface grain size and volume concentration. Vertically, the grain size and the volume concentration is increasing with the depth. The SPC in syzygial tide is 0.016～0.716kg/m³,in neap tide is 0.0167～0.261kg/m³.(4) The spectral curve of water surface shows unimodality in the low turbid water and bimodality in the high turbid water.(5) The principles of the water color remote sensing are introduced. The popular retrieval models of the Case II water are compared with each other. After the analyzing the correlation between the normalized reflectance and the SPC, the retrieving models are built based on the four sensitive bands extracted from all. The exponent equation [C=1216.76exp(x/3.39)-1371.18) is selected to be the optimal retrieval model. The independent of this model is R₇₁₆/R₅₅₁.(6) After the analyzing the correlation between the grain size and the reflectance, it is found that the 582nm reacts to the variation of the grain size most sensitively. The models between the band ratio and the SPC are built, combined with the SPC sensitive bands: 716nm and 725nm. After the analysis and the validation, the retrieval model of the SPC, which gets rid of the influence of the grain size, is obtained.Finally, the suggestions for the further work are put forward.