Temporal Transformation of Barrier Islands around Nakdong Estuary
The Nakdong Estuary system near Busan, South Korea consists of dynamic shorelines characterized by morphological transformations that result from both natural disasters (typhoons and flooding) and construction projects (Nakdong Estuary Dam, gates in the West Nakdong River and Busan New-ports). This study aims to synthesize existing data for tides, waves, bathymetry and meteorological data obtained from a variety of institutions with the objectives of (1) identifying and ranking major factors that influence morphological transformations and (2) determining how these factors influence morphological change over time. These objectives were met by analyzing patterns of flow and sediment transport using Center Point Distance Analysis (CPDA) method to analyze morphological changes and Coastal Modeling System (CMS) platform to predict sediment transport and subsequence morphological changes caused by constructions. Barrier islands in Nakdong estuary have a clockwise rotation and growth to the east and west between 1972 and 2013. In the case of seaward shorelines, shorelines grew to offshore between 1982 and 2013. CMS was then used to model morphological change in the absence of construction of the Nakdong Estuary Dam and Busan New-ports to estimate the impact of these structures on the topography within the Nakdong Estuary. Nakdong Estuary dam was major factor of decreasing amount of inflow suspended sediment from Nakdong River. If the dam is not constructed in the study area, estuary area is filled by sediment and becomes land. The result of this research will be applied when development and construction plans are established.