Back
 JWARP  Vol.9 No.6 , May 2017
Impact of Large Fresh Water Discharges into Hakata Bay Due to Torrential Rain Using Nested Two-Dimensional Convective-Dispersive Model
Abstract: In this study, numerical simulation of a two-dimensional convective-dispersive model in Hakata Bay, Japan, is performed to analyze the impact of major river discharges due to torrential rain in Fukuoka City. Tank models are applied to calculate river discharges, which are taken into consideration as river inflow in the hydrodynamic model of Hakata Bay. A two-way nesting “edge” technique is developed and applied in the model in order to consider the influence of narrow and complex geographical features. The area around “Island City” and Imazu Bay are calculated in high resolution. The resulting model has high reproducibility since the calculated river discharges, tidal current, and salinity show good agreement with observed data. To analyze the impact of large river discharges, the calculation period is set from 11 September 2002 to 21 September 2002 since there was torrential rain on September 16 in the given year in Fukuoka City (163.5 mm/d). The results show that low-salinity water covered the whole of the inner part of Hakata Bay, and water of lower salinity than outer sea water (<34.0 psu) spread out to the bay’s mouth two days after the torrential rain event. Fresh water covered the entire area of Imazu Bay and flowed out from the mouth of the Bay after the torrential rain event. The behavior of fresh water after a few days of torrential rain was remarkably different from normal discharge river flow. These results indicate that the environment in Imazu Bay can be degraded severely by torrential rain. Therefore, countermeasures to protect ecosystems in Hakata Bay must be examined immediately.
Cite this paper: Fukuda, A. , Tabata, T. , Honda, Y. , Hiramatsu, K. and Harada, M. (2017) Impact of Large Fresh Water Discharges into Hakata Bay Due to Torrential Rain Using Nested Two-Dimensional Convective-Dispersive Model. Journal of Water Resource and Protection, 9, 553-565. doi: 10.4236/jwarp.2017.96036.
References

[1]   Babazaki, M., Hachiyama, H., Uchida, T. and Shimatani, Y. (2009) A Case Study of Mitigation in Mishima Area of Hakata Bay, Fukuoka. Journal of Japan Society for Impact Assessment, 7, 84-91.

[2]   Akiyama, J., Shigeeda, M. and Nomura, S. (2013) Numerical Investigation of Characteristics of Flood Flow in the Onga River Basin and Inundation Flow in Iizuka City due to Torrential Rain. Japan Society of Civil Engineers, 69, 1579-1584. (In Japanese with English Summary)

[3]   Sato, Y., Komatsu, E., Nagare, H., Uehara, H., Yuasa, T., Okubo, T., Okamoto, T. and Kim, J. (2011) Construction and Validation of Lake Biwa Basin Simulation Model with Integration of Three Components of Land, Lake Flow, and Lake Ecosystem. Journal of Japan Society on Water Environment, 34, 125-141.
https://doi.org/10.2965/jswe.34.125

[4]   Hayashi, S. and Yamada, T. (2015) Effective Rainfall Amount and Slope Surface Failure Caused by Heavy Precipitation—Study on the Seepage Flow in the Soil La-yer of a Slope. Journal of the Japanese Geotechnical Society, 10, 157-162.
https://doi.org/10.3208/jgs.10.157

[5]   Nakaegawa, T., Kobashi, T. and Ishizaki, Y. (2014) Statistics of Annual Mean Total Water Storage in the Tank Model in Japan. Proceedings of Japan Society of Civil Engineers, 70, 343-348.

[6]   Rahman, M.M., Paul, G.C. and Hoque, A. (2013) Nested Numerical Scheme in a Polar Coordinate Shallow Water Model for the Coast of Bangladesh. Journal of Coastal Conservation, 17, 37-47.
https://doi.org/10.1007/s11852-012-0216-1

[7]   Debreu, L., Marchesiello, P., Penven, P. and Cambon, G. (2012) Two-Way Nesting in Split-Explicit Ocean Models: Algorithms, Implementation and Validation. Ocean Modelling, 49-50, 1-21.
https://doi.org/10.1016/j.ocemod.2012.03.003

[8]   Hu, B.S. and Kot, S.C. (1997) Numerical Model of Tides in Pearl River Estuary with Moving Boundary. Journal of Hydraulic Engineering, 123, 21-29.
https://doi.org/10.1061/(ASCE)0733-9429(1997)123:1(21)

[9]   Smagorinsky, J. (1963) General Circulation Experiments with the Primitive Equations. Monthly Weather Review, 91, 99-164.
https://doi.org/10.1175/1520-0493(1963)091<0099:GCEWTP>2.3.CO;2

[10]   Komatsu, T. (1993) Accurate Numerical Simulation of Diffusion Phenomena. Notes of the 29th Summer Seminar on Hydraulic Engineering, 1993 Course A, 5, 1-14. (In Japanese)

[11]   Uchiyama, Y. (2004) Wetting and Drying Scheme Based on a Modified Logarithmic Law for Three-Dimensional Terrain-Following Coastal Ocean Models. Annual Journal of Coastal Engineering, Japan Society of Civil Engineers, 51, 351-355. (In Japanese with English Summary)

[12]   Nihei, Y., Sato, K., Nadaoka, K., Kumano, R. and Nishimura, T. (2003) Development of a New Multi-Nesting Approach for Coastal Current Simulation. Proceedings of Japan Society of Civil Engineers, 740, 171-183.

[13]   Martinsen, E.A. and Engedahl, H. (1987) Implementation and Testing of a Lateral Boundary Scheme as an Open Boundary Condition in a Barotropic Ocean Model. Coatal Engineering, 11, 603-627.
https://doi.org/10.1016/0378-3839(87)90028-7

[14]   Sugawara, M. (1985) Tank Model—For the Derivation of River Discharge from Rainfall. Journal of Geography, 94, 209-221. (In Japanese with English Summary)
https://doi.org/10.5026/jgeography.94.4_209

[15]   Noto, F., Maruyama, T., Hayase, Y., Takimoto, H. and Nakamura, K. (2010) An Evaluation of Snow Storage Depth in the Tedori River Basin Using Tank Model. Japanese Society of Irrigation, Drainage and Rural Engineering, 78, 265-271.

[16]   Tsutsumi, H., Okamura, E., Ogawa, M., Takahashi, T., Yamaguchi, H., Montani, S., Kohashi, N., Adachi, T. and Komatsu, T. (2003) Studies of the Cross Section of Water in the Innermost Areas of Ariake Bay with the Recent Occurrence of Hypoxic Water and Red Tide. Oceanography in Japan, 12, 291-305. (In Japanese with English Summary)
https://doi.org/10.5928/kaiyou.12.291

[17]   Nakamura, M., Shinagawa, A., Toda, K. and Nakao, S. (1997) Tolerance of 4 Bivalves from Lakes Shinji and Nakaumi to Environmental Factors. Fish Farming, 45, 179-185. (In Japanese with English Summary)

 
 
Top