世界银行-孟加拉国红树林海岸恢复力：潜在地点的识别、三重红利的评估和成本估算（英）

Policy Research Working Paper11175Mangroves for Coastal Resilience in BangladeshIdentification of Potential Locations, Assessment of Triple Dividends, and Cost EstimationAlejandra Gijón MancheñoLuke BranderBramka Arga JafinoIgnacio UrrutiaSwarna KaziUrban, Disaster Risk Management, Resilience and Land Global DepartmentJuly 2025 Produced by the Research Support TeamAbstractThe Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about development issues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry the names of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely those of the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank and its affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent.Policy Research Working Paper 11175Bangladesh is highly vulnerable to extreme weather events due to its frequent exposure to floods and extensive low-ly-ing areas. Coastal flood risks are expected to increase due climate change. Therefore, Bangladesh has been upgrading its coastal embankment system to enhance flood safety. This initiative includes not only hard flood defense infrastructure, but also nature-based solutions through planting mangroves on the seaside of embankments. Mangroves, serving as nat-ural flood barriers, have been utilized in Bangladesh for coastal protection since the 1960s. However, their integra-tion with embankment designs and their benefits in carbon sequestration remain underexplored. This paper consoli-dates current knowledge on the role of mangroves in coastal resilience in Bangladesh, incorporating recent studies and new analyses on their benefits on (i) flood risk reduction, (ii) livelihood enhancement, and (iii) carbon sequestration. The estimated benefits are mapped along the country’s coastal system. 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. The findings aim to guide future investments in integrating mangroves into coastal protection systems, highlighting their triple dividends for building resilience.This paper is a product of the Urban, Disaster Risk Management, Resilience and Land Global Department. It is part of a la