INFLUENCE OF TIDAL INLET DEPTH ON WATER LEVEL RESPONSE AND SALINITY INTRUSION IN A LAGOON

Kazuya Watanabe, Hitoshi Tanaka

Abstract


The Nagatsura-ura Lagoon in Miyagi Prefecture, Japan is a semi-enclosed water area that has been used for aquaculture of oyster for these forty years. Recently, however, death of oysters has frequently occurred due to anoxic water near the bottom, and is a big concern among stakeholders. The Nagatsura-ura Lagoon and Oppa Bay are connected by shallow tidal inlet, and its water depth greatly affects hydrodynamics and water environment in the lagoon. In this study, time variation of water level in the lagoon in response to tidal variation is investigated through spectral analysis to quantify the role of water depth in the hydrodynamic process. Furthermore, the relationship between the inlet water depth and the salinity concentration intruding into the lagoon is examined through 3-D numerical simulation.

Keywords


water level variation; 3D numerical simulation;spectral analysis

References


Fukuoka, S., Matsushita, T., Miura, S., Kurokawa, T., Funabashi, S. and Nakamura, M. 2002. On salinity variation connected brackish lake, Annual Journal of Hydraulic Engineering, 46, 899-1. (in Japanese) http://dx.doi.org/10.2208/prohe.46.899

Galperin, B., Kantha, L. H., Hassid, S., and Rosati, A. 1988. A quasi-equilibrium turbulent energy model for geophysical flows, Journal of the Atmospheric Sciences, 45, 55-62. http://dx.doi.org/10.1175/1520-0469(1988)045<0055:AQETEM>2.0.CO;2

Keulegan, G.H. 1967. Tidal Flow in Entrances, U.S. Army Corps of Engineers, Committee on Tidal Hydraulics, Technical Bulletin, 14, 102p.

Mellor, G. L., and Yamada, T. 1982. Development of a turbulence closure model for geophysical fluid problems, Rev. Geophys.Space Phys., 20, 851–875. http://dx.doi.org/10.1029/RG020i004p00851

Narita, M., Ishikawa, T. and Takahashi, A. 2002. Characteristics of the river mouth on the Takase River, Proceedings of Coastal Engineering, JSCE, 49, pp.526-530.(in Japanese) http://dx.doi.org/10.2208/proce1989.49.526

Purwanto, B.S., Tanaka, H., Kanayama, S., Takasaki, M. and Yamaji, H. 2007. Mid-layer intrusion simulation in Nagatsura-ura Lagoon, Proceedings of 32nd IAHR Congress, 2007.(CD-ROM)

Sato, K., Matsuoka, M., and Kazumitsu, K., 1993. Efficient calculation method of 3-D tidal current. Proceedings of Coastal Engineering, JSCE, 40, 221-225.(in Japanese). http://dx.doi.org/10.2208/proce1989.40.221

Tanaka, H., Nagabayashi, H. and Yamauchi, K. 2000. Observation of wave set-up height in a river mouth, Proceedings of 27th International Conference on Coastal Engineering, 3458-3471.

Tanaka, H. and Lee, H. S. 2003. Influence of jetty construction on morphology and wave set-up at a river mouth, Coastal Engineering Journal, 45(4), 659-683.http://dx.doi.org/10.1142/S0578563403000956


Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.