Seasonal and Inter-Annual Shoreline Dynamics Along Tam Tien Beach, Central Vietnam: Insights from Satellite Imagery Analysis

Abstract

The shoreline of Quang Nam province in Central Vietnam has been experiencing persistent erosion, posing a significant threat to coastal communities and their livelihoods. This study analyzes eight years of Landsat-7/8/9 and Sentinel-2 images to examine shoreline changes along Tam Tien Beach in Quang Nam during the period 2015–2022, identifying patterns of erosion and deposition. The analysis of 75 transects over an 11 km stretch of sandy shoreline revealed that approximately 84% of the transects exhibited erosion, with transects 44 to 60 showing significant retreat of shoreline averaging around 2.5 m/year. The results also demonstrated a significant seasonal variability related to monsoon regimes. The translational and rotational shift of the shoreline was examined, and the influence of wave energy flux and wave direction were clarified. The study also applied Empirical Orthogonal Eigenfunction analysis to explore the relationship between shoreline translation, rotation, and rate of change. Under the expected future climate change, the study also underlines the vulnerability of Central Vietnam to severe erosion events. These findings are the key to predicting coastal impacts, designing effective protection structures, mitigating erosion, and managing coastal resources.