Understanding Shoreline and Riverbank Changes Under the Effect of Meteorological Forcings

In a context of changing climate, extreme events, like floods or weather are expected to frequently increase. Hence, understanding the role of meteorological forcings affected shoreline evolution and riverbank erosion in spatio-temporal scales, especially Vu Gia - Thu Bon river coast located in Central Vietnam, is significantly remarkable. This is fundamental to interpret the information of shoreline and riverbank erosion-accretion trends. Plus, this helps coastal managers and policy makers give the effective solutions, interventions and strategies for adaptation and responding to possible changes in shoreline and riverbank. The goal of this paper, therefore, is to provide a deeper understanding the effects of meteorological forcings on shoreline and riverbank changes. To do this, the Google Earth images and field survey results in topography changes are implemented. Landsat images are added to better quantify the changes in shoreline and riverbank. More importantly, meteorological forcings extracted from the meteorological metadata and models are carefully analysed to have an insight into physical mechanisms and shoreline and riverbank behaviors. The results confirmed that the northeast winds are accompanied by stronger-than-normal tropical cyclones, which cause high waves on the river system. This is one of the main reasons for stronger shoreline erosion in Cua Dai estuary in the recent years. Additionally, the northeast wind-generated waves in winter are much stronger than the southeast wind-generated waves during the summer. The factors significantly contribute to the changes in shoreline and riverbank. Finally, precipitation is more abundant and northeast winds are more frequent and stronger than normal. This considerably affects the erosion tendency on the river sections at the positions like GiaoThuy or Ky Lam Bridge.