Estimation of shoreline position and change from satellite images considering tidal variation

This paper presents the one-line shift method of determining mean sea level datum-based shoreline positions from three sequential satellite images that take into account tidal variations. Tidal correction through data interpolation on originally computed tides to accurately predict tidal level with a root mean squared error less than 10 cm. The determined mean sea level datum-based shoreline positions of the Waisanding Sandbar by the proposed method differ from those by RTK GPS by about 43.09–193.58 m. Based on the acceptable shoreline positions from satellite images, the whole area of the Waisanding Sandbar is proven to be decreasing since 1999 and migrating landward to the west of Taiwan.