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Conserving Mangroves for Storm Protection Services. Saudamini Das, Assoc Prof. Institute of Economic Growth, Delhi, and SANDEE Fellow. Economics of Climate Change Adaptation Workshop, USAID, UNDP, ADAPT Asia-Pacific, 24-26 Oct 2012, Bangkok.
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Conserving Mangroves for Storm Protection Services Saudamini Das, Assoc Prof. Institute of Economic Growth, Delhi, and SANDEE Fellow Economics of Climate Change Adaptation Workshop, USAID, UNDP, ADAPT Asia-Pacific, 24-26 Oct 2012, Bangkok The views expressed are those of the presenter and should not be attributed to either UNDP or USAID. Furthermore, it is strongly recommended that both the PowerPoint slides and the videos of the presentation of content included herein are viewed in conjunction in order that statements appearing in the PowerPoint slides are not interpreted out of context.
Approach to Storm Hazard • Emphasis on scientific & engineering approach to storm risk management by policy • Better prediction • Early warning • Evacuation • Storm shelters, storm resistant houses, dikes • There are limitations & uncertainty • Accurate prediction of intensity, landfall with sufficient time gap • Limited compliance of community to State warning: (wait & watch, faith on GOD, less faith on Govt) • All investments limited to protection of movable properties • Uncertainty from Climate change • Bay of Bengal, South China Sea and North Pacific Ocean are core area of Cyclogenesis (IPCC 1997)
Natural buffers are important - need to examine their role • Do mangroves provide storm protection ? • - historical context, • - concerns, knowledge gap • - careful examination of this service • How do they fare vis-à-vis the other approaches like early warning, storm shelter, dikes, etc? • Is mangrove preservation an economically viable adaptation strategy to climate change?
Storm protection by Mangroves - Background • Debated since the Bhola Cyclone (Nov 1970) in East Pakistan (Bio.Conserv, 1971) • Much focus due to prominent natural disasters like 2004 tsunami, Katrina, Sidr, Nargis, Aila etc. • Accepted as a prominent ecosystem service (Barbier et al, Science 2008; Day et al, Science 2007; Gedan et al, Climate Change 2010). • Most of the empirical works are questioned.
Present Study • Quantifies Mangrove Protection during 1999 Super Cyclone • Examines mangrove protection for movable as well as immovable properties (house damages) • Large sample and maximum possible control to separate Mangrove impact on Cyclone Damage • Use Scientific, GIS and Socio-Economic data • Robust finding that mangroves reduced cyclone damages and support for mangrove conservation to get storm protection
Mangrove Forest cover before 1950 (30,766 hectares) Bhadrakh Kendrapada Jagatsinghpur Super Cyclone Path Bay of Bengal Puri 7
Mangrove Forest cover in 1999 (17,900 hectares) Bhadrakh Kendrapada Jagatsinghpur Super Cyclone path Bay of Bengal Puri 8
B A
How do I identify Mangrove Impact during Cyclone? • Estimate Cyclone Damage Function using multiple control variables along with mangroves • Use variables to control for: • - Physical features of mangrove habitat • - Cyclone Impact • - Topography • - Hydrology • - Infrastructure • - Socio-Economic Well-being • - Governmental Institution • Calculate avoided damages from marginal effect 12
Confounding effect of mangrove with effect of distance from coast Village B ● Village A Mangrove ● Sea
---- with effect of Mangrove Habitat • Exclude village A, include village C • Test that protection at B is due to vegetation, not habitat A● C● B● Mangrove habitat Mangrove Sea
Marginal effect - death (villages within 10km from coast)
Weighted Average Storm Protection Value of km width of Mangroves per Village (in INR)
Will we optimize benefit by going back to 1950 level? NO X axis: km width of mangrove \ village Y axis: averted death \ km width of mangrove \ village Turning point: at approximately 1.5 km \ village
Mangroves vs. others Source: Das & Vincent ongoing (not to be quoted) • 74% of all the Swept Away houses and 80% of all the cattle loss in Kendrapada occurred from villages next to dikes. Source: Das (sandee@10)
Should we preserve mangroves to adapt to climate change? Yes, on both meteorological and economic grounds. • Meteorology: • Orissa is the most cyclone prone state in east coast of India. • Frequency of high intensity cyclones increasing over years.
Opportunity cost of conserving mangroves Market value of land in coastal Kendrapada: Rs172, 970 \ ha Annual return from land (8%): Rs13, 837\ha\yr Annual return from land(12%): Rs20, 756\ha\yr Benefit from conserving mangroves Storm protection value (only for 3 damages):Rs182, 080\ha Annual Probability of VSCS and SC: 0.15\yr Annual Storm Protection Value (for 3 damages): Rs27, 312\ha\yr Economic cost & benefit (1999 prices)
Does reduction in only death risk justify mangrove preservation? Benefit from death risk reduction • No of lives saved: 0.01 \ ha • VSL for Orissa from Indian wage-risk study: Rs10,918,132\ • Annual probability of VSCS &SC: 0.15\yr • Annual benefit from reduction of death risk : Rs17, 469\ha\yr • Opportunity cost of Mangrove Preservation: Rs13, 837 – Rs20, 756\ha\yr Benefit ≥ Cost • VSL for India: Rs13.7-14.2 to Rs55.5-60.6million at 2000 - 01prices ≈ Rs17.8-18.4 to Rs72 -78.12m at 2002-08 Per capita income.
Conclusions • Mangroves reduced human death, livestock loss and house damages during the T-7 Super cyclone of October 1999. • Human death toll would have been nearly doubled in absence of mangroves. • Annualized storm protection benefit of mangrove for reducing three damages was found higher than annual return from land justifying mangrove conservation as a viable adaptation strategy to climate change.
Policy Implications • Use of engineering approach to manage storm disaster may not be the only option. • Along with engineering and scientific approaches, mangrove protection and regeneration should be undertaken to manage storm risk more efficiently • Along with movable properties like lives, mangroves also protect immovable assets like houses.