Measuring time-series tidal flat area variation using multi-temporal Sentinel-1 at Nakdong river estuary, Korea

Abstract

Barrier islands, a type of tidal flats, in estuary regions are essential for safeguarding inland areas from natural disasters like typhoons and tsunamis, acting as natural barriers. These dynamic landscapes are subject to continuous transformations influenced by tidal movements, oceanic waves, river currents, human interventions, and the shifting patterns of seasons. This study focuses on the crucial task of monitoring longterm tidal flat area changes, specifically at the Nakdong River Estuary in Korea. Over the last five decades, the region has experienced significant topographical changes due to human activities, including the impact of dike openings altering sedimentation patterns. Utilizing long-term satellite data, particularly from multitemporal Sentinel-1, the research aims to accurately measure these area changes by mitigating tidal and seasonal effects. Preliminary results indicate a noticeable decrease in the tidal flat area until 2017. The study underscores the importance of correlating major environmental events with area variations to understand the dynamic changes in tidal flats. In future research, we plan to analyze the long-term variability of the Nakdong River Estuary's tidal flat by dividing the area into three segments centered around water channels. Additionally, we aim to compare the impact of various events such as changes in estuary flow, typhoons, and rainfall on the tidal flat area changes.