Nearshore Topographical Changes and Coastal Stability in Nam Dinh Province, Vietnam

Nguyen Thanh Hung,Do Minh Duc,Vu Dinh Cuong,Dinh Thi Quynh

doi:10.3390/jmse8100755

Abstract

Recently, the coastal zone in Vietnam has experienced more intensive sea attacks due to severe typhoons, climate change, and humsection an activities. Sea level rise has been recorded all along the coast. Moreover, sand exploitation and engineering measures have significantly changed local reliefs and led to apparent sea water level change on the coast of Nam Dinh province. Coastal erosion and sea dike failures have become a serious problem in the region. The site investigation of nearshore topography shows the recent changes to the coast. Hydrodynamic models show that changes of relief and increased wave attacks on dikes. The main reason for sea dike instability is soil erosion due to wave topping; meanwhile, the dikes are stable in terms of sliding. The coast should be reinforced with properly constructed revetments, wave topping preventive measures, and nearshore sand exploitation should be halted.

Highlights

The Intergovernmental Panel on Climate Change (IPCC 2007) reported that during the 21st century, the sea level will rise another 18 to 59 cm due to global warming
Based on the data of cross-shore profiles were measured over the periods as stated in the above section, six typical cross sections representing the coast of Quat Lam, Thinh Long, and Rang Dong areas are used for analysis of nearshore topographical changes
Simulation results with an assumption of no change in current seabed elevation showed that maximum wave height in sea level rise (SLR) scenarios SC4 in Quat Lam was 1.43 m, which was 7 cm higher than wave height in SC3, equal to 5.1%

Summary

Introduction

The Intergovernmental Panel on Climate Change (IPCC 2007) reported that during the 21st century, the sea level will rise another 18 to 59 cm due to global warming. Climate change-related geohazards on the coast include erosion, inundation and flooding, saline intrusion, and sea dike instability. Land subsidence, and tropical cyclones are strengthening the coastal erosion [12]. A typhoon landing at high spring tide can cause a disaster of inundation, flooding, and saline intrusion on the coast. Sea level rise causes larger wave pressure on the sea dikes, making them more unstable in typhoons and storm surges. Among the alternatives available for countering these threats, applying soil stabilization and soil improvement with geosynthetics are promising strategies for coastal structures that must sustain severe wave action and storm surges [14,15,16,17]

Results

Discussion

Conclusion