April 13, 2009

Mangroves can save lives in cyclones

A study of the 1999 super cyclone that hit eastern India suggests villages shielded from the storm surge by mangrove forests fared better than other areas.

The study by researchers at India's University of Delhi and Duke University in the United States 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. It showed areas protected by mangrove forests experienced significantly fewer deaths than did less-protected villages.

Mangroves are dense forests of trees and shrubs that grow in brackish, low-lying coastal swamps in the tropics and subtropics.

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 Duke University Professor Jeffrey Vincent. "Taking other environmental and socioeconomic factors into account, villages with wider mangroves suffered significantly fewer deaths than ones with narrower or no mangroves.

We believe this is the first robust evidence that mangroves can protect coastal villages against certain types of natural disasters, he added.

Vincent conducted the analysis with Saudamini Das of the University of Delhi. Their findings appear in the early online early edition of The Proceedings of the National Academy of Sciences.