How effective were mangroves as a defence against the recent tsunami?

F. Dahdouh-Guebas1,,L.P. Jayatissa3,D. Di Nitto1,J.O. Bosire4,D. Lo Seen5andN. Koedam2,

1 Biocomplexity Research Team, c/o General Botany and Nature Management, Mangrove Management Group, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
2 General Botany and Nature Management, Mangrove Management Group, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
3 Department of Botany, University of Ruhuna, Matara, Sri Lanka.
4 Kenya Marine and Fisheries Research Institute, PO Box 81651, Mombasa, Kenya.
5 Institut Français de Pondichéry, Rue St. Louis 11, BP 33, 605 001 Pondicherry, India.

Corresponding author


Summary

Whether or not mangroves function as buffers against tsunamis is the subject of in-depth research, the importance of which has been neglected or underestimated before the recent killer tsunami struck. Our preliminary post-tsunami surveys of Sri Lankan mangrove sites with different degrees of degradation indicate that human activity exacerbated the damage inflicted on the coastal zone by the tsunami.

Observations by the International Tsunami Survey Team in Sri Lanka

Philip L.-F. Liu,1 Patrick Lynett,2* Harindra Fernando,3 Bruce E. Jaffe,4 Hermann Fritz,5 Bretwood Higman,6 Robert Morton,4 James Goff,7 Costas Synolakis8

In response to the 26 December 2004 tsunami, a survey team of scientists was dispatched to Sri Lanka. Measurements made by the team show that the tsunami elevation and runup ranged from 5 to 12 meters. Eyewitnesses report that up to three separate waves attacked the coast, with the second or third generally the largest. Our conclusion stresses the importance of education: Residents with a basic knowledge of tsunamis, as well as an understanding of how environmental modifications will affect overland flow, are paramount to saving lives and minimizing tsunami destruction.

1 School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
2 Department of Civil Engineering, Texas A&M University, College Station, TX 77845, USA.
3 Department of Mechanical and Aerospace Engineering, Arizona State University, Tempe, AZ 85287, USA.
4 Pacific Science Center, United States Geological Survey, Santa Cruz, CA 95060, USA.
5 School of Civil and Environmental Engineering, Georgia Institute of Technology, Savannah, GA 31407, USA.
6 Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA.
7 National Institute of Water and Atmospheric Research, Ltd., Lyttelton, New Zealand.
8 Department of Civil Engineering, University of Southern California, Los Angeles, CA 90089, USA.