Mangroves for coastal resilience in Bangladesh: Identification of potential locations, assessment of triple dividends, and cost estimation

The study identifies some of the most beneficial mangrove sites to be combined with embankment designs, such as a belt south of polder 45 (Amtali) with an average width of 1.77 kilometers, and a belt around the Kukri-Mukri polder with an average width of 1.82 kilometers. These mangrove forests can reduce the required thickness for slope protection by up to 80 percent, offer carbon service benefits of US$13,120 per hectare (over 2022-50, at a 6 percent discount rate), and provide livelihood benefits of more than US$22,000 per hectare. Other wide mangrove belts are found in Sandwip and Mirersarai.

Considering the comparison between mangrove restoration costs and direct benefits, direct livelihood benefits associated to provisioning services like fisheries, timber, and other raw materials (22,039 USD ha-1 - 30,330 USD ha-1 ) already exceed the restoration costs (7,467 USD ha-1 -7,781 USD ha-1 ) in 252 of 255 sites. Next to those benefits, mangroves could provide direct cost reductions by influencing embankment designs. T