Abstract
Shoreline variation on Nha Trang Coast, Vietnam, is analyzed based on a set of continuous camera images which is obtained from two video-cameras monitoring. As a result, the retreat of shoreline appeared seasonally on this coast, especially strong northeast monsoon waves have caused the severe erosion. In addition, in order to understand more comprehensively the shoreline behavior, this study also analyzes the data of shoreline evolution by using Empirical Orthogonal Function (EOF). The results of EOF analysis indicate that the contribution of the first component is about 89% out of total, therefore the other components are negligible. Besides, temporal eigenfunction of the first component reflects the seasonal variation of morphology corresponding to seasonal longshore sediment transport in response to the changes of wave direction in each monsoon period. Following that, estimation of net longshore sediment transport rate is carried out based on depth of closure variation (Dc) in consideration of seasonal change of wave conditions. The differential response to the change of net longshore sediment transport rate, which is calculated from a constant Dc and seasonal values of Dc, is also clarified in this study.
