Contributions to Coastal Flooding Events in Southeast of Vietnam and their link with Global Mean Sea Level Rise

Luis Melo de Almeida,Nguyen Viet,Benoit Meyssignac,Rafael Almar

doi:10.3390/geosciences8120437

Abstract

This work analyzes the components of the total water level (TWL) that cause flooding in a tropical coastal area (Nha Trang beach, Southeast of Vietnam), and examines their link with global mean sea level rise (GMSLR). Interactions between the wave induced run-up (R) and astronomical tide (AT) were responsible for 43% of the 35 flooding events identified between 1993 and 2015. Most of these events (97%) took place during the winter monsoon season, when long-lasting extreme R and positive non-tidal residual (NTR) are likely to occur. Removal of the GMSLR trend from the NTR was found to affect the flood occurrence of 17% of these events, while the trend in wave height did not have any detectable impact. Our research highlights the direct connection between global climate changes and coastal flooding events.

Highlights

Coastlines worldwide are under threat because of climate change [1,2]
The aim of the present work is to investigate the components of total water level (TWL) which are most influential in driving coastal flooding on a tropical coastal area (Nha Trang coast, Southeast of Vietnam), and examine their link to global mean sea level rise (GMSLR)
The results show that the altimeter non-tidal residual (NTR) had a good correlation with the local tide gauge NTR (CC = 0.79)

Summary

Introduction

On the physical basis of climate change [3,4] have projected that the global mean sea level (GMSL) will rise by 0.5 to 1.2 m by the year 2100 under various emissions scenarios because of warming oceans and declining ice volumes. Global mean sea level rise (GMSLR) is already under way and satellite altimetry indicates that sea level has been rising at an average rate of 3.03 ± 0.15 mm/year since 1993 [5]. Assessments of coastal vulnerability caused by climate change has tended to focus on the impact of sea-level rise [7], recent studies demonstrate that climate-induced variations in the wave climate have the potential to cause coastal impacts (e.g., shoreline retreat and flooding) that are more important than those related to sea-level rise itself [8,9]

Objectives

Methods

Results

Conclusion