Grantee Research Project Results
Quantifying Local Benefits of Mangrove Plantation Shelterbelt in Coastal BangladeshEPA Grant Number: FP917318
Title: Quantifying Local Benefits of Mangrove Plantation Shelterbelt in Coastal Bangladesh
Investigators: Chow, Jeffrey
Institution: Yale University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2011) RFA Text | Recipients Lists
Research Category: Fellowship - Emerging Environmental Approaches and Challenges: Social Sciences , Academic Fellowships
(1) What direct uses do mangrove plantations provide to rural coastal communities? (2) How do benefits from mangrove plantations contrast to those from natural mangroves? (3) Based on socioeconomic and geophysical data, is there evidence that mangroves mitigate economic damages associated with storm surge?
To answer the first question, this study conducts structured interviews with coastal villagers to determine the extent of direct local use. Secondly, this study reviews and updates a forest valuation exercise undertaken for the Sundarbans Reserve Forest, a natural mangrove forest in Bangladesh, by the Food and Agriculture Organization of the United Nations (FAO). Addressing the third question, this study employs a modified Ricardian analysis to investigate whether mangrove plantations impart protective benefits that materialize as gains in farm net revenues. This study focuses on the economic impacts of a mangrove plantation rather than mortality effects because the development of shelters and early warning systems continually will reduce the loss of life due to tropical storms in the long run. Agricultural and aquacultural production would remain vulnerable, however, and would require protection via man-made defenses. Finally, quantification of economic benefits allows calculation of benefit-cost ratios using data on plantation management costs.
The initial surveys undertaken suggest that village use of the mangrove plantations may be meager. Local uses include fuelwood harvest, animal fodder collection, fruit collection and recreation. Because the plantations are largely monocultures that also lack the extensive networks of streams characteristic of the Sundarbans, a natural mangrove ecosystem, it is expected that direct use of plantations is largely confined to fuelwood collection. Consequently, the diversity and value of direct uses associated with natural mangroves would exceed those of the plantations. This study models mangrove coverage in three ways: presence or absence of mangrove vegetation between the farm and the coast; the width of mangrove vegetation between the farm and the coast; and the total impedance generated by mangrove vegetation. The parameters associated with each specification can be interpreted respectively as the marginal effects of mangrove presence, mangrove width and total mangrove resistance on net revenues. These three variables are expected to have a positive relationship with net farm revenues because all three variables represent greater impedance to storm surges traveling inland, and because net revenues are expected to be inversely related to storm surge vulnerability. The econometric analysis is more likely to discern significant effects from the 2000 dataset than the 2005 dataset due to greater storm activity in 2000. Other specifications will be explored as this project progresses.
Potential to Further Environmental / Human Health Protection
Socioeconomic, geographical and climatic characteristics make Bangladesh one of the countries most sensitive to the damaging impacts of climate change. The country’s low topography, underdevelopment and heavy reliance on agriculture make it especially vulnerable. Rises in sealevel and sea surface temperatures will lead to greater intensity of tropical storms, threatening poor households, coastal infrastructure and agricultural productivity. The Reduction of Climate Change Hazards through Coastal Afforestation with Community Participation is Bangladesh’s top priority climate adaptation project. Its primary objective is to create a thick coastal forest belt to stabilize shorelines, reduce storm surges and prevent soil salination. However, if mangrove plantations are less effective at protection than expected, they may create a false sense of security and put more lives and property at risk. By shedding light on the current socioeconomic impact of previous efforts in Bangladesh, this research will inform this and other mangrove plantation initiatives, such as those in Indonesia, Thailand and Vietnam, which are now underway as a response to expected climate change.