A Study on the Characteristics of the Sedimentary Environments by Using SAR Data in the Ganghwa Tidal Flat

The Ganghwa tidal flat is located on the west coast of Korea. This area is covered by the sand, mud and mixed(sandy / muddy) sediments. The grain-size in the tidal flat is coarser to the seaward and finer to the eastern flat. The objectives of this study are to characterize the sedimentary environments based on the analysis of correlation between SAR data and factors of sedimentation. Therefore, we compared the backscattering coefficients and the coherence of JERS-1, ENVISAT, ERS-2 and ALOS images of SAR data. In the results of our analysis, we found a relationship between the backscattering coefficient and in-situ sediment grain-size. The backscattering coefficients appeared to be high in the region containing more of sand fraction because of the coarser grain-size and rougher surface. The coarse grain-size was more affected by the tide than the fine grain-size since the coarser grain-size has the smaller viscosity. Therefore the coherence is lower in the sand dominant area.