A STUDY ON THE CHARACTERISITCS OF THE SEDIMENTARY ENVIRONMENTS BY USING SAR DATA IN THE GANGHWA TIDAL FLAT

Abstract

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 where the grain-size 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. We used both the backscattering coefficient of JERS-1, ENVISAT, ERS-2 and ALOS images and the coherence of interferometric pair. In the results of our analysis, we found a relationship between SAR-derived measurements and in-situ sediment grain-size. The backscattering coefficient appeared to be greater in the region containing more of sand fraction because of the coarser grain-size and rougher surface. The coarse grain such as sand-sized sediment was more affected by the tide since the coarser grain-size has the smaller viscosity. Therefore the coherence is lower in the sand dominant area.