著者

佐々木 寧 田中 規夫 湯谷 賢太郎 ホモチュエン サマン

出版者

埼玉大学工学部

雑誌

埼玉大学紀要. 工学部 第1編 第1部 論文集 = The Science and Engineering Reports of Saitama University (ISSN:18804446)

巻号頁・発行日

no.38, pp.49-57, 2005

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This study reports the damage at the coastal area in south Thailand by Indian Ocean Tsunami occurred at Dec.26.2004. The investigated area covered about 250 km at Andaman seaside from Phuket to Ranong. For elucidating the effect of vegetation on tsunami protection, the representative vegetation was classified according to the stand structure of the tree. The representative trees were classified into five and their stem diameter (d), tree height, branch structure, density of the trees and the forest-width to the Tsunami-direction were investigated. From the survey, mangrove, especially Rhizophora apiculata forest, was effective to protect Tsunami damage with its complex root structure. Anacardium occidentale was also effective with its large diameter branches at low height from the ground level. On contrary, Casuarina equisetifolia has assumed little effect to reduce the velocity when their diameter grow large (d>0.5m) with large stem-spacing (7-30m).

著者

佐々木 寧 ホモチュエン サマン

出版者

埼玉大学工学部

雑誌

埼玉大学工学部紀要 第一部 論文集

巻号頁・発行日

no.40, pp.51-58, 2006

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From 22 th to 23th May 2006, a landslide occurred the mountain area of Uttaradit in northern Thailand, where is popular fruit growing and slight rain commonly. In that time, the rainfall in 48 hours was over 400 mm, many landslide occurred, especially with a lot of drift wood and left more than 100 persons dead or missing. It was observed many case of surface landslide, large trees and secondary forest of bamboo collapsed easily.

著者

秋元 梢 本間 俊司 古閑 二郎 松本 史朗

出版者

埼玉大学工学部

雑誌

埼玉大学紀要. 工学部 第1編 第1部 論文集 (ISSN:18804446)

巻号頁・発行日

vol.38, pp.35-39, 2005-03

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Unsteady mass transfer from a two-dimensional drop is solved numerically with boundary element method. The domain is decomposed into two sub-domains for cylindrical drop and surrounding fluid, and boundary elements are arranged between the sub-domains. The system equation for boundary elements is derived by a direct method and by a finite difference approximation for time derivative. The solutions are independent of the number of elements on the interface of the drop and the external boundary of the domain. The number of meshes inside the domain, on the other hand, affects the numerical solutions. It is necessary for good approximation to select appropriate resolution of the computational domain and the time step.