Coastal vegetation structures and their functions in tsunami protection: experience of the recent Indian Ocean tsunami
Coastal vegetation structures and their functions in tsunami protection: experience of the recent Indian Ocean tsunami
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DOI：
10.1007/s11355-006-0013-9
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发表时间：
2007-04
影响因子：
2
通讯作者：
N. Tanaka;Y. Sasaki;M. Mowjood;K. Jinadasa;S. Homchuen
中科院分区：
文献类型：
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作者：
N. Tanaka;Y. Sasaki;M. Mowjood;K. Jinadasa;S. Homchuen
这项研究探讨了沿海植被对海啸灾害的影响，根据2004年12月26日印度洋海啸后进行的实地观察。研究地点覆盖斯里兰卡南部海岸约250公里（19个地点）和泰国安达曼海岸约200公里（29个地点）。根据其生境和乔木林分结构，将代表性植被分为6个类型。利用观测到的树种特征，分析了植被结构对阻力的影响。阻力系数，包括树木的垂直结构，Cd-all，和单位面积的植被厚度（在海啸方向的植被的累积树干直径），dNu（d：树木的参考直径，Nu：单位面积的树木数量），随物种分类而变化很大。在野外调查和资料分析的基础上，对两种红树植物Rhizophora apiculata和Rhizophora mucronata（以下简称R.（apiculata-type）、多种红树林以及生长在海滩沙地上的代表性树木香樟（Pandanus odoratissimus），由于其复杂的气生根结构，被发现在提供保护免受海啸破坏方面特别有效。垂直方向上两层植被，P.此外，小乔木和大乔木的水平植被结构对增加阻力和截留漂浮物、断枝、房屋和人员也很重要。垂直结构也为被海啸冲上岸的人们提供了一个有效的软着陆，或者当海啸波袭来时，为人们提供了一个有效的软着陆，尽管它的Nu与R相比并不大。apiculata-type和P.最有味道的此外，红树林内的小溪和红树林内的空隙。木贼植被被认为是有效的延迟海啸波。在今后的沿海景观规划、恢复和沿海资源管理中应考虑到这一信息。
This study explored the effects of coastal vegetation on tsunami damage based on field observations carried out after the Indian Ocean tsunami on 26 December 2004. Study locations covered about 250 km (19 locations) on the southern coast of Sri Lanka and about 200 km (29 locations) on the Andaman coast of Thailand. The representative vegetation was classified into six types according to their habitat and the stand structures of the trees. The impact of vegetation structure on drag forces was analyzed using the observed characteristics of the tree species. The drag coefficient, including the vertical stand structures of trees,Cd-all, and the vegetation thickness (cumulative trunk diameter of vegetation in the tsunami direction) per unit area,dNu(d: reference diameter of trees,Nu: number of trees per unit area), varied greatly with the species classification. Based on the field survey and data analysis,Rhizophora apiculataandRhizophora mucronata(hereafterR. apiculata-type), kinds of mangroves, andPandanus odoratissimus, a representative tree that grows in beach sand, were found to be especially effective in providing protection from tsunami damage due to their complex aerial root structure. Two layers of vegetation in the vertical direction withP. odoratissimusandCasuarina equisetifoliaand a horizontal vegetation structure of small and large diameter trees were also important for increasing drag and trapping floating objects, broken branches, houses, and people. The vertical structure also provided an effective soft landing for people washed up by the tsunami or for escaping when the tsunami waves hit, although itsdNuis not large compared withR. apiculata-type andP. odoratissimus. In addition, the creeks inside mangroves and the gaps insideC. equisetifoliavegetation are assumed to be effective for retarding tsunami waves. This information should be considered in future coastal landscape planning, rehabilitation, and coastal resource management.