An optimal approach for morphological changes of tidal flat using multi-satellite sensors

The tidal flats are important in an ecological and economical way, and continuous management is required because it shows very dynamic changes. In the Korean tidal flats, efficient management is more emphasized because the heavily economically active. In this study, we propose a way to create a topographic elevation and area theme map of the tidal flat using multiple satellites and to update it efficiently. The waterline method was used to generate a satellite based digital elevation model (DEM), and the topographic elevation was calculated using the tidal information at the time the satellite image was acquired. The exposure frequency of tidal flats was calculated through time-series images and compared and verified with the unmanned aerial vehicle-based DEM to present an optimal topographic elevation map generation method. For the satellite-based tidal flat area theme map, the tidal flat was classified using the supervised classification method, and compared and verified with the tidal flat area data provided by the Ministry of Oceans and Fisheries. The multi-satellite-based DEM of tidal flat could produce a precise theme with an error of about 21 cm with only 5 months of image collection, and even if the image collection period was longer, the accuracy was not significantly improved. In the case of the satellite-based tidal flat area, the accuracy was about 95% compared to the reference data, and it was analyzed that the tidal flat area, which was missing some surveys, could also be detected. Through the results of this study, it was confirmed that the satellite-based topographic elevation and area map production method can drastically shorten the update cycle while maintaining a level of accuracy similar to the current survey method.