Analysis of the abrupt change of halophyte around Ganghwa tidal flats

Abstract

The objective of this study is to analyze the abrupt change of halophyte especially annual plants, S. japonica. S. japonica is very sensitive to change in physical stress because it is located at the lowest level at the zonation of halophyte. Min (2005) found that S. japonica covered salt marsh changes only over a small range, nearly all the seeds being located directly beneath their maternal plants. Therefore, an abrupt change in S. japonica directly represents an environmental change of the residence area. The boundary and distribution of S. japonica was extracted from the TerraSAR-X, Kompsat-2 and Landsat ETM+. A large patch of S. japonica on the eastern parts of Donggum-do has disappeared since 2009, while on the western parts of the island a large patch has steadily expanded to the seaward as shown in the classification results. The patch of P. australis around Donggum-go has steadily increased. The possible reasons for the sudden death of S. japonica are sea level rise, climate change, changes in tide and currents and sedimentation rates. Mean sea level and temperature were analyzed based on the gauged tidal data and the gauged meteorological data. Tidal current was simulated to know the effects caused by constructions. Sedimentation rates were measured using vernier calipers. From the analysis these data, we knew that the Ganghwa tidal flats have suffered hydrodynamic changes becaphyte. Min (2005) found that S. japonica covered salt marsh changes only over a small range, nearly all the seeds being located directly beneath their maternal plants. Therefore, an abrupt change in S. japonica directly represents an environmental change of the residence area. The boundary and distribution of S. japonica was extracted from the TerraSAR-X, Kompsat-2 and Landsat ETM+. A large patch of S. japonica on the eastern parts of Donggum-do has disappeared since 2009, while on the western parts of the island a large patch has steadily ex