Mangroves Save Lives in Storms, Study of 1999 Super Cyclone Finds
A new study of storm-related deaths from a super cyclone that hit the eastern coast of India in 1999 finds that villages shielded from the storm surge by mangrove forests experienced significantly fewer deaths than ones that were less protected.
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 in the Nicholas School.
“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 appeared in a paper in the online early edition of The Proceedings of the National Academy of Sciences this past spring.
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 from 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.”
Das and Vincent’s 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.
