Study on the sediment classification in a tidal flat considering the pattern of channel distribution

Abstract

We examined the relations of the channel distribution with the sedimentary facies in Geunso-bay tidal flat, Korea. The tidal channel networks were extracted from an aerial photograph. The patterns of the channel distribution were compared with one another for several sites in terms of the fractal analysis, channel density. The channels in each sediment facies showed relatively constant meandering patterns, however, the density and the complexity were distinguishable for each facies. The 2nd fractal dimension which indicates the branch pattern of the tidal channel were 1.87 in the mud flat, 1.41 in the mixed flat, and about 1.30 in the sand flat. The channel density in the mud flat was 0.035-0.06 m/m2 which was the highest among the three sedimentary facies.Using the differences in fractal dimensions and tidal channel densities in each sedimentary facies, we tried to adjust the sedimentary facies classification which had been generated from the interpolation of the surveyed data. For each grain size sampling site, the percentage of sand particles was compared with the channel density.It was shown that the higher the sand percentage, the lower the tidal channel density except at a few points. The locations showing the exceptional pattern were mainly inside the tidal channel or adjacent to the inland. We suggest that those differentiated features of tidal channels among the different sedimentary facies should beapplied to the surface sedimentary facies classification in the tidal flat.