Advertisement

Tsunamis pp 293-304 | Cite as

Fluid Force on Vegetation Due to Tsunami Flow on a Sand Spit

  • Kentaro Imai
  • Hideo Matsutomi
Part of the Advances in Natural and Technological Hazards Research book series (NTHR, volume 23)

Abstract

One of the features of the 1998 Papua New Guinea tsunami is that a maximum tsunami height of 14.8 m was observed on the vegetated sand spit of Sissano lagoon that faced the tsunami source. This tsunami caused a large number of human casualties. The coastal vegetation in the western Pacific Ocean countries attracts attention from an economical and environmental point of view as a tool of tsunami countermeasures. Fluid force on vegetation mainly consists of drag force F D , inertia force F M , and linear wave making resistance force F W . In this paper, the ratios of these forces and corresponding coefficients are examined. It is clarified that F M reaches 50 % of the maximum drag force F Dmax at the early stage of inundated flow, and that F D and F W are dominant at the quasi-steady state after the early stage. The drag coefficient C D is found to be 0.9–1.5, the mass coefficient C M is 1.5–2.5, and the linear wave making resistance coefficient θ' is 0.02–0.07. C D and C M change with the same tendency as those of group of piles in open channel flows, and they decrease as vegetation density κ increases.

Keywords

Drag Force Linear Wave Tsunami Source Fluid Force Inundation Depth 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Matsutomi, H., Y. Kawata, N. Shuto, Y. Tsuji, K. Fujima, F. Imamura, M. Matsuyama, T. Takahashi, N. Maki and S. S. Han: Flow Strength on Land and Damage of the 1998 Papua New Guinea Tsunami, Advances in Natural and Technological Hazards Research, Vol.18, Kluwer Academic Publishers, pp.179–195, 2001.Google Scholar
  2. Shuto, N.: Effectiveness and limit of tsunami control forests, Proceedings of Coastal Engineering, JSCE, Vol.32, pp465–469, 1985. (in Japanese)Google Scholar
  3. Stoker, J. J: The formation of breakers and bores, Communications on Pure and Applied Mathematics, Vol. 1, pp. 1–87. 1948.Google Scholar
  4. Takayama, T., T. Nagai, O. Kikuchi and K. Moroishi: Motions and Mooring Forces of a Rectangular Floating Body in Wave (1st report), REPORT OF P.H.R.I, pp71–103, 1980. (in Japanese)Google Scholar
  5. Morison, J. R, M. P. O'Brien, J. W. Johnson and S. A. Schaaf: The force exerted by surface waves on piles, Petroleum Transaction, AIME, Vol. 189, pp.149–154. 1950.Google Scholar
  6. Noji, M., F. Imamura and N. Shuto: Numerical simulation of movement of larger rocks transported by tsunamis, Proceedings of Coastal Engineering, JSCE, Vol.40, pp176–180, 1993. (in Japanese)Google Scholar
  7. Tsuchiya, Y. and M. Yamaguchi: Total wave force on a vertical circular cylindrical pile, Proceedings of the Japan society of civil engineers, pp.11–21, 1974. (in Japanese)Google Scholar
  8. Matsutomi, H. and T. O hmukai: Laboratory Experiments on fluid force of tsunami flooded flows, Proceedings of Coastal Engineering, JSCE, Vol.46, pp336–340, 1999. (in Japanese)Google Scholar

Copyright information

© Springer 2005

Authors and Affiliations

  • Kentaro Imai
    • 1
  • Hideo Matsutomi
    • 2
  1. 1.Department of Production and Civil Engineering Graduate school of Engineering and Resource ScienceAkita UniversityAkita
  2. 2.Department of Civil and Environmental EngineeringAkita UniversityAkita

Personalised recommendations