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Dynamical Properties of Coastal Currents in the Northwestern Part of Iriomote Island Part. 2—Funauki and Shirahama Bays

  • Jun YoshinoEmail author
  • Tomokazu Murakami
  • Akiyuki Ukai
  • Hiroyoshi Kohno
  • Shinya Shimokawa
  • Kouta Nakase
  • Akira Mizutani
Chapter
Part of the Springer Oceanography book series (SPRINGEROCEAN)

Abstract

This chapter presents investigation of the physical properties of tidal flows in two semi-closed bays connected with a channel based on theoretical, observational and numerical frameworks. Shirahama Bay with shallower water and Funauki Bay with deeper water in the northwestern part of Iriomote Island are mutually connected by a channel. Tidal flows in both bays are expected to be much more complex than those of Sakiyama and Amitori bays, discussed in Chap.  4. According to the tidal flow dynamics in Chap.  4, the seawater exchange in Shirahama Bay is more active because of its shallower water floor, whereas the seawater exchange in Funauki Bay is more stagnant because of its deeper water floor. Consequently, the low-salinity water originating from a river is likely to be retarded in Funauki Bay under near-calm conditions. In the case of a smaller aspect ratio (shallower and longer) of the connecting channel, the seawater exchange among the bays becomes inactive. In the case of the moderate aspect ratio of the connecting channel, which is comparable with those of both bays, the seawater exchange among the bays reaches a maximum. For a larger aspect ratio (deeper or shorter) of the connecting channel, the seawater exchange will stagnate not only between the bays, but also between the bays and the open ocean. The aspect ratio of the connecting channel, which strongly affects the tidal currents in both bays, is expected to strongly influence on the dispersions of eggs and seeds in the coastal ocean ecosystems in this region.

Keywords

Iriomote Island Shirahama Bay Funauki Bay Coastal current Seawater exchange Tidal flow River flow Connecting channel 

Notes

Acknowledgements

The technical assistance with observational and numerical investigations was graciously provided by Mr. Keigo Kita in Kasugai City Office.

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Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  • Jun Yoshino
    • 1
    Email author
  • Tomokazu Murakami
    • 2
  • Akiyuki Ukai
    • 3
  • Hiroyoshi Kohno
    • 4
  • Shinya Shimokawa
    • 2
  • Kouta Nakase
    • 3
  • Akira Mizutani
    • 4
  1. 1.Faculty of EngineeringGifu UniversityGifuJapan
  2. 2.Storm, Flood and Landslide Research DivisionNational Research Institute for Earth Science and Disaster ResilienceTsukubaJapan
  3. 3.Environment Business DivisionPenta-Ocean Construction Co., Ltd.TokyoJapan
  4. 4.Okinawa Regional Research Center, Tokai UniversityYaeyamaJapan

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