Integration of spatial variables derived from remotely sensed data for the mapping of the tidal surface sediment distribution

Choi, J. K., Ryu, J. H. and Eom, J., 2011. Integration of spatial variables derived from remotely sensed data for the mapping of the tidal surface sediment distribution. Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal Symposium), 1653 – 1657. Szczecin, Poland, ISSN 0749-0208 The sedimentary environments of tidal flats on the west coast of Korea are subjected to continuous change due to both natural and artificial causes. Thus, knowledge of the spatial distribution of surface sediments in a tidal flat is important in understanding the nature of coastal environmental change. This paper reports on a preliminary study of a novel approach to classifying the surface sedimentary facies in a tidal flat. A map of sedimentary facies was compiled by integrating spatial variables related to the facies. The digital number value of the IKONOS NIR band, which is a remotely sensed image with high spatial resolution, was constructed as a spatial database that represents spectral reflectance. The distribution of the tidal channel network was extracted from the IKONOS image and the density of tidal channels was built as a spatial database. The relative weighting of two variables, i.e. IKONOS NIR band and the density of tidal channels, was determined based upon a previous study, and a group of grain-size samples was analyzed to estimate the boundaries between sedimentary facies. The classification showed a relatively high level of accuracy in terms of comparison with another group of grain-size samples. The results demonstrate that the proposed method is applicable to the mapping of surface sedimentary facies in a tidal flat based on remote sensing images with high spatial resolution. The use of sufficient control factors and a suitable model for quantitative estimates of the weighting for each factor is expected to enable precise mapping of the distribution of surface sedimentary facies in tidal flats. ADDITIONAL INDEX WORDS: Surface sediment distribution, Spectral reflectance, Tidal channel, Spatial variables, Remote sensing