Institute of Plant Production and Agroecology in the Tropics and Subtropics, University of Hohenheim, 70593 Stuttgart, Germany.
Proc Natl Acad Sci U S A. 2011 Nov 15;108(46):18612-7. doi: 10.1073/pnas.1013516108. Epub 2011 Nov 7.
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.
在海啸事件中，人员伤亡和基础设施破坏主要取决于海震强度和近海特性。在陆地上，波浪能通过重力（海拔）和摩擦（地表覆盖）而衰减。绿化带已被推广为抵御波浪冲击的“生物盾牌”。然而，由于缺乏它们在这种极端事件中性能的定量证据，绿化带被批评为造成了一种虚假的安全感。本研究使用了 180 个与印度尼西亚亚齐西海岸超过 100 公里长的垂直剖面，分析了沿海植被（特别是人工种植的树木）对 2004 年海啸影响的影响。卫星图像；土地覆盖图；土地利用特征；茎直径、高度和种植密度；以及文献综述用于开发土地覆盖粗糙度系数，以考虑不同土地利用对波浪推进的阻力。应用空间广义线性混合模型，我们发现，虽然距离海岸是影响（伤亡和基础设施破坏）的主要决定因素，但定居点前现有的沿海植被也显著减少了平均 5%的伤亡。相比之下，村庄后面茂密的植被危及人类生命并增加了结构破坏。回流携带的碎片可能导致了这些不同的土地覆盖效果。为了可持续和有效的沿海风险管理，定居点的位置是至关重要的，而沿海植被的保护潜力，如其空间布置所决定的，应被视为一个重要的生计提供者，而不仅仅是一个生物盾牌。
