The study, conducted by researchers at the University of Delhi and Duke University, analyzed deaths in 409 villages in the poor, mostly rural Kendrapada District of the Indian state of Orissa, just north of the cyclone's landfall.
"Our analysis shows a clear inverse relationship between the number of deaths per village and the width of the mangroves located between those villages and the coast," said Jeffrey R. Vincent, Clarence F. Korstian Professor of Forest Economics and Management at Duke's Nicholas School of the Environment.
"Taking other environmental and socioeconomic factors into account, villages with wider mangroves suffered significantly fewer deaths than ones with narrower or no mangroves," Vincent said. "We believe this is the first robust evidence that mangroves can protect coastal villages against certain types of natural disasters."
Vincent conducted the analysis with Saudamini Das of the University of Delhi's Swami Shradanand College. Their findings appear in a paper in this week's online early edition of The Proceedings of the National Academy of Sciences.
Mangroves are dense forests of trees and shrubs that grow in brackish, low-lying coastal swamps in the tropics and subtropics. In 1944, mangroves covered nearly 31,000 hectares of land in Kendrapada District and the average village had 5.1 kilometers of mangroves between it and the coast. Since then, nearly half the area has been cleared, mostly for rice production. Today, the average width of mangroves between the villages and the coast has shrunk to 1.2 kilometers.
The 1999 storm, which made landfall on Oct. 29, killed nearly 10,000 people, more than 70 percent of whom drowned in its surge.
Using statistical models, Das and Vincent predicted there would have been 1.72 additional deaths per village within 10 kilometers of the coast if the mangrove width had been reduced to zero.
"This is a measure of the life-saving impact of the mangroves that remained in 1999," Vincent said. "It implies that they cut the death toll by about two-thirds."
Although mangroves evidently saved fewer lives than an early warning issued by the Indian government, the retention of the remaining mangroves in Orissa is economically justified, Vincent believes, even without considering the many other environmental benefits they provide, such as acting as nurseries for economically and environmentally vital fisheries, or sites for ecotourism. Previously published estimates of Indians' willingness to pay to reduce the risk of accidental deaths are higher than Das and Vincent's estimate of the cost of saving lives in Orissa by retaining mangroves.
The study does not assess mangroves' ability to reduce deaths from tsunamis, Vincent cautions, because of key differences in their wave dynamics. Storm surges have shorter wave lengths than tsunamis, and relatively more of their energy is found near the surface of the water. Mangroves' ability to protect villages against tsunamis has been a point of controversy in the scientific and policy communities since the 2004 Indian Ocean tsunami. Das and Vincent designed their study to overcome criticism leveled at studies examining the effects of mangroves on that disaster.
The study was supported by the South Asian Network for Development and Environmental Economics (SANDEE), with research facilities provided by the Institute of Economic Growth in Delhi, India.
Tim Lucas | EurekAlert!
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
23.10.2017 | Event News
17.10.2017 | Event News
10.10.2017 | Event News
23.10.2017 | Life Sciences
23.10.2017 | Physics and Astronomy
23.10.2017 | Health and Medicine