| Journal Article |
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| Article Title | Influence of coastal vegetation on the 2004 tsunami wave impact in west Aceh | | Author | Juan Carlos Laso Bayas, Carsten Marohn, Gerd Dercon, Sonya Dewi, Hans Peter Piepho, Laxman Joshi, Meine van Noordwijk and Georg Cadisch | | Year | 2011 | | Journal Title | Proceedings of the National Academy of Sciences of the United States of America | | Institution | The National Academy of Sciences of the USA | | Pages | 18612 - 18617 | | Call Number | JA0420-11 | | Keywords | glimmix, tsunami mitigation, vegetation effects, food security |
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| Abstract: |
| In a tsunami event human casualties and infrastructure damage are determined predominantly by seaquake intensity and offshore properties. On land, wave energy is attenuated by gravitation (elevation) and friction (land cover). Tree belts have been promoted as “bioshields” against wave impact. However, given the lack of quantitative evidence of their performance in such extreme events, tree belts have been criticized for creating a false sense of security. This study used 180 transects perpendicular to over 100 km on the west coast of Aceh, Indonesia to analyze the influence of coastal
vegetation, particularly cultivated trees, on the impact of the 2004 tsunami. Satellite imagery; land cover maps; land use characteristics; stem diameter, height, and planting density; and a literature review were used to develop a land cover roughness coefficient
accounting for the resistance offered by different land uses to the wave advance. Applying a spatial generalized linear mixed model, we found that while distance to coast was the dominant determinant of impact (casualties and infrastructure damage), the existing coastal vegetation in front of settlements also significantly reduced casualties by an average of 5%. In contrast, dense vegetation behind villages endangered human lives and increased structural damage. Debris carried by the backwash may have contributed to these dissimilar effects of land cover. For sustainable and effective
coastal risk management, location of settlements is essential, while the protective potential of coastal vegetation, as determined by its spatial arrangement, should be regarded as an important livelihood provider rather than just as a bioshield. |
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