Visualization and Statistical Analysis on the Submarine Topography of the Radial Tidal Sandy Ridge System in the south Yellow Sea

Abstract:

The Radial Tidal Sandy Ridge System (RTSRS) in the south Yellow Sea has very complex submarine topography. It is fundmental and vital for the scientific research, coastal planning and exploitation to have subtle digital terrain model, 3-dimention visual model and statistics of the different topographic units. The bathymetric survey data were recently collected in the north RTSRS using single-beam echo sounding technique. Kriging interpolation method is considered as the best choice to generate the digital terrain model for the current bathymetric data according to the residual analysis on the measured and interpolated value. The RTSRS can be visually subdivided into four topographic sub-units, including shoal, ridge, channel and broad valley through using the water-depth color bar. The microtopography of ridges and channels can be visually displayed by the profile curvature, like the sub-scale channels on the ridges and the sub-scale ridges in the channels, and quantitatively calculated in area and their percentage of the totall. Quantitatvie analyses on the slope of the ridges and channels shows the RTSRS is dominated by the horizontal-to-weakly-inclined topography with slope angle less than 5°, which accounts for 60% of the total in area and is mainly distributed on the broad valleys, the top of the ridges and at the middle of the channels. The topographic plan curvature and tangential curvature bear some information of marine hydrodynamics, in that the inner shallow region with strong currents tends to have negative value, and the outer deep region with weak currents has positive value of the tow parameters.