CHARACTERISTICS OF TIDAL FLAT PROFILES IN THE YELLOW RIVER DELTA

Data from tidal gauges, tidal flat profiles and surface sediments analysis were used to study 3 different types of Yellow River delta coast. Particle size analysis shows that, from the mean high water level to low water level, sediments on all the profiles become coarser. The trend is more pronounced in the profiles near the river mouth and erosional coast than that in stable coast. The content of water in sediments ranges between 12.2% and 32.2%, and the shear stress between 0.25 and 0.35 kg/cm². By integrating remote sensing images and profiles data with GIS, we get much knowledge about sediment dynamics of the delta tidal flat. The tidal flat that is controlled by man-made dykes shows common characteristics of a beach in profile shape and in planform. Its profile is concave-up and the planform is a curved dry/wet line facing dominant wave direction, which indicates strong influences of wave actions. A small crevasse-splay formation is seen on the tidal flat in the north part of the river mouth, where sediments are coarser than that at the other part and show dark fan shade in the remote sensing image. It is found that the low water line from the remote sensing images does not correspond with the field data.