In the heart of the Red River Delta, a battle is unfolding between the relentless forces of nature and the delicate balance of coastal ecosystems. Hai Hau beach, a stretch of coastline in Nam Dinh province, is at the forefront of this struggle, facing severe erosion that threatens not only its natural beauty but also the stability of nearby infrastructure and the energy sector.
The erosion at Hai Hau beach is not a new phenomenon, but the factors driving it are complex and multifaceted. Dr. Nguyen Manh Hung, a researcher at the Institute of Mechanics, National Center for Science and Technology of Vietnam, has been delving into the intricacies of this issue. His recent study, published in the Vietnam Journal of Mechanics, sheds light on the interplay between wave climate, river dynamics, and sediment transport.
The study reveals that the cut-off of the Ha Lan river mouth in 1955 and the construction of the Hoa Binh dam upstream have significantly reduced the sediment supply to the area. “The reduction in sediment supply has left the coastline vulnerable to erosion,” Dr. Hung explains. “The prevailing wave climate, combined with the complex topography of the Balat river mouth, exacerbates the problem, promoting erosion along the coastal line.”
To understand the dynamics at play, Dr. Hung and his team employed a two-dimensional random wave transformation model. This model, fed with a 20-year time series of hindcast waves, allowed them to compute the longshore sediment transport along Hai Hau beach. The findings underscore the critical role of wave climate and sediment supply in shaping the coastline.
The implications of this research extend beyond the immediate environmental concerns. The energy sector, particularly those with infrastructure along the coast, stands to be significantly impacted. Offshore wind farms, for instance, require stable seabed conditions for their foundations. Erosion can undermine these conditions, leading to costly repairs and potential safety hazards. Similarly, coastal power plants and oil rigs are at risk from the encroaching sea.
Dr. Hung’s work highlights the need for a holistic approach to coastal management. “We need to consider not just the immediate impacts of erosion but also the long-term effects on infrastructure and the environment,” he says. “This requires a multidisciplinary approach, integrating hydrology, geomorphology, and engineering.”
The study published in the Vietnam Journal of Mechanics (Mechanics Journal of Vietnam) serves as a wake-up call for policymakers and industry stakeholders. It underscores the urgency of addressing coastal erosion and the need for innovative solutions. As the energy sector continues to expand, the stability of coastal infrastructure will become increasingly critical. Dr. Hung’s research provides a foundation for future developments in this field, paving the way for more resilient and sustainable coastal management practices.
