Week 13: Coastal Hazards

Coastal Hazards in Vietnam: Issues and Strategies for Resilience

Vietnam's huge 3,260-kilometer coastline—home to over 20 million people and important economic sectors—is under increasing threat from both natural processes and human activity (410). This dynamic land-sea interface faces some of Asia's most severe coastal hazards, which are worsened by climate change, fast development, and environmental degradation. From the sediment-starved Mekong Delta to the typhoon-battered central regions, Vietnam's coastal zones demonstrate the complex interplay of geology, hydrology, and human habitation patterns.

Vietnam's Coastal Geography and Hazards Profile

Vietnam's coastal morphology varies significantly between regions, resulting in distinct hazard vulnerabilities:

The subsiding Mekong Delta: This lush agricultural region in the south confronts multiple challenges, including land subsidence (up to 5.7 cm/year in some areas), saltwater intrusion, and rising sea levels, which might claim 40% of the delta by 2100. The delta's elevation averages only 0.8 meters above sea level, making it particularly vulnerable to storm surges and tidal inundation. The deteriorating central coast: Sand mining, upstream dam construction, and typhoon waves cause severe beach erosion in provinces such as Quang Nam (up to 20-30 meters per year near river mouths). Since 2014, the iconic Cua Dai Beach near Hoi An has receded by more than 150 meters, putting tourism infrastructure at risk. The typhoon-prone northern coast: The Red River Delta and Gulf of Tonkin have the highest frequency of tropical cyclones (5-6 per year), with storm surges that regularly exceed 3 meters.

These physical weaknesses are combined with extensive human settlement—nearly 35% of Vietnam's population lives in coastal regions, with major towns such as Da Nang and Hai Phong located on low-lying deltas. The World Bank predicts that 12 million Vietnamese are now at danger of severe flooding, with climate change expected to expose an additional 4.5 million people to coastal flooding by 2050.

Primary Coastal Hazards for Vietnam

Erosion and Land Loss

Vietnam loses approximately 500 hectares of coastal land annually to erosion, with some hotspots receding at alarming rates of 20-50 meters per year. The central provinces between Thua Thien-Hue and Binh Thuan are particularly affected, where sand mining and river damming have reduced sediment delivery to coasts by 50-70% in some river systems. Mangrove deforestation (Vietnam lost 50% of its mangroves between 1943 and 2011) has removed natural buffers against waves. Poorly planned infrastructure, including seawalls and tourism developments, often exacerbates erosion downdrift. Satellite analyses show that 42% of Vietnam's coastal hotels sit adjacent to eroding beaches, while two-thirds of the sea dike system fails to meet safety standards. 

Storm Surge and Flooding

Vietnam, one of the world's most storm-prone countries, averages 6-8 typhoons each year, with central regions like Khanh Hoa taking the worst. The 2017 Typhoon Damrey produced $1 billion in damages and killed 107 people, demonstrating the combined threats of wind damage, flooding, and storm surges. Flood risks are increasing because of sea level increase (20 cm since the 1960s, escalating to 8.7 cm by 2050). Land subsidence due to groundwater extraction (up to 10 cm/year in Ca Mau). Urbanization that replaces permeable surfaces with concrete increases runoff.

Saltwater Intrusion

The Mekong Delta's $10 billion aquaculture industry and rice cultivation (17% of global trade) are under threat from saltwater moving upstream. During the 2019–2020 drought: Saltwater penetrated 50-110 kilometers inland, impacting 200,000 houses. 275,260 hectares of rice paddies were affected. Freshwater scarcity disturbed the lives of 685,000 individuals. According to projections, maintaining present production could cost $10 billion in engineering controls such as sluice gates. 

Marine Plastic Pollution

Vietnam is one of the top five global sources of ocean plastic, leaking between 280,000 and 730,000 metric tons each year. Coastal communities create 3.7 million tons of plastic waste each year (only 10-15% is recycled), cluttering rivers and worsening flood hazards. Hot places include: Tourist beaches like Phu Quoc and Nha Trang have accumulation rates of up to 2,500 items/m². In fishing villages, abandoned gear accounts for 30% of marine litter. River outlets that direct interior waste to the sea.

Vietnam's Coastal Hazard Management Strategies

Vietnam has taken a multifaceted strategy to addressing its expanding coastal risks, integrating legislative frameworks, engineering solutions, and natural adaptations.

Policy and Institutional Frameworks

Since the 1990s, Vietnam has created a comprehensive disaster risk management (DRM) system, backed by important policies. The 2021 National Strategy for Natural Disaster Prevention (extended to 2030 with a vision to 2050) intends to reduce disaster-related deaths by half and ensure that all households receive hazard notifications. The National Adaptation Plan (NAP) incorporates climate resilience into sectoral planning and is funded by $1.9 million from the Green Climate Fund. The Disaster Prevention and Control Law (2013) develops a coordinated response structure at the national and municipal levels. These strategies employ the Pressure-State-Response (PSR) paradigm, which connects dangers (storms, erosion) to environmental conditions and societal responses.

Engineering and Nature-based Solutions

Vietnam uses a combination of hard infrastructure and ecosystem-based adaptations:

1. Hard defenses. A 2,659-kilometer sea dike system, with 67% remaining poor. Storm surge barriers, including the $400 million Ca Mau embankment. To counteract seawater intrusion, modernized irrigation systems support 252,000 crops.

2) Ecosystem-Based Adaptation. Mangrove restoration, with 12,000 hectares replanted in the Mekong Delta. Dune restoration in erosion-prone places such as Quang Nam. The $51.5 million Forest Carbon Partnership encourages communities to safeguard coastal ecosystems.

Reference

https://vietnam.vnanet.vn/english/long-form/comprehensive-solutions-for-coastal-erosion-prevention-380103.html 

Fund, Green Climate. “FP013: Improving the Resilience of Vulnerable Coastal Communities to Climate Change Related Impacts in Viet Nam.” Green Climate Fund, 30 June 2016, www.greenclimate.fund/project/fp013.

“Ecosystem-Based Adaptation on the Northern Central Coast of Vietnam: Restoration and Co-Management of Degraded Dunes and Mangroves.” International-Climate-Initiative.com, 2015, www.international-climate-initiative.com/en/project/ecosystem-based-adaptation-on-the-northern-central-coast-of-vietnam-restoration-and-co-management-of-degraded-dunes-and-mangroves-18-ii-160-vnm-a-eba-dunes-and-mangroves/. Accessed 2 May 2025.

Olson, Kenneth R. “The Mekong Delta in Vietnam and Cambodia Is Subsiding and in Need of Remediation.” Open Journal of Soil Science, vol. 12, no. 5, 20 May 2022, pp. 171–192, www.scirp.org/journal/paperinformation.aspx?paperid=117236, https://doi.org/10.4236/ojss.2022.125007.

Group, World Bank. “Viet Nam Leads in Forest Protection through Innovative Carbon Program.” World Bank, World Bank Group, 23 Sept. 2024, www.worldbank.org/en/news/feature/2024/08/23/viet-nam-leads-in-forest-protection-through-innovative-carbon-program.