By blocking storm surge and dampening waves, the sprawling mangrove forests of northern Viet Nam’s Red River Delta have long provided a measure of protection against flooding for the people who call the region home, a number that currently stands at over 23 million. Yet, as a changing climate intensifies flood risk in the Red River Delta even further, aquaculture activities and changes in land use, among other factors, have threatened the long-term sustainability of the region’s mangrove forests. While mangrove forests in the Red River Delta saw severe loss in the 2000s, more recent conservation efforts led by the government of Viet Nam have since reversed this trend. 

The Global Facility for Disaster Reduction and Recovery (GFDRR) and the World Bank are supporting the government of Viet Nam in its ongoing efforts to integrate the mangrove forests of the Red River Delta into its broader system of coastal protection, which also includes traditional risk reduction infrastructure such as the region’s extensive dike system. 

Specifically, support has been provided toward analytical work that is expected to inform decision-making by the government around these efforts, including with respect to whether specific mangrove protection interventions should complement or replace traditional flood risk reduction infrastructure, as well as where such interventions would be most cost-effective in the Red River Delta. In conducting the analytical work, the team utilized the Nature-Based Solutions (NBS) Opportunity Scan, a tool that leverages geospatial analysis and modeling to identify and quantify the potential benefits of NBS such as mangroves. 

“We hope that the analyses conducted will help us to have the full information to select sites where the protection of mangrove forests proves to be the most valuable.” 
—Nguyen Truong Son, Deputy Director, Viet Nam Disaster and Dike Management Authority, Ministry of Agriculture and Environment

For starters, the team’s analytical work has revealed significant flood risk reduction benefits of preserving mangroves in the Red River Delta, even without constructing or reinforcing physical embankments. Recent efforts to expand mangrove coverage in the region have often been followed by the construction or reinforcement of physical embankments to reduce flood risk. The team’s findings suggest that this may not always be necessary. The team estimated that the avoided annual flood damages by 2050 would be equal to $138.8 million, even assuming no reinforcements were made to embankments over the next 25 years. 

In addition, the team’s analytical work has also shed light on the potential costs and benefits of mangrove restoration across six sites in the Red River Delta. A key goal here is to assist the government of Viet Nam in prioritizing mangrove restoration efforts across the six sites. The team found that in four of the six sites, mangrove protection is already economically viable solely based on the reduced costs in terms of embankment reinforcement. In the remaining two sites, the team found that mangrove conservation is still cost-effective when ecosystem services and carbon mitigation benefits are considered.

Furthermore, the analytical work has also unearthed insights into potential areas of additional study that might further inform Viet Nam’s decision-making around its mangrove protection efforts. For instance, the team noted that across several of the six sites, local studies, which investigate the causes of mangrove loss, may paint a fuller picture of the costs and benefits of mangrove protection