Numerical simulation on coastal environment in Kamaishi Bay (Japan) by MEC model

A 3-D Marine Environmental Committee (MEC) model was conducted to describe the specific circulation patterns of hydrodynamics of water quality and ecosystems driven by climate change forcing in Kamaishi Bay at Miyagi Prefecture in the Great East Japan. The major concern of this study is the diffusion of pollutants caused by 2011 Earthquake and Tsunami disaster impacts on marine ecosystem. In this study, we simulate the changes of water quality and ecosystems structure from January 2009 to December 2012. The MEC model has been used to predict the distributions of various key water quality indicators and tide flow in the different layer of Kamaishi Bay. High correlation is obtained between simulation derived and measurement derived tidal characteristics. We also simulated the effects of breaking water effects on the tide, currents and integrating aquaculture and fisheries. The wind driven flow using mean seasonal wind forcing (NE, SE, and SW) creates different circulations over Kiamichi Bay. Similarly, the temperature and salinity distribution of Kamaishi Bay waters is characterized by strong seasonal variations. The water quality is intensely affected by pollutants and has continually deteriorated due to increased discharges of domestic and industrial waste as well as an increased loading in anthropogenic contamination into the Bay. The results were found that measured and simulated contaminations of radioactive materials were under the environmental standards in Japan. Observed and simulated DO, T-N and T-P concentrations were not so large different from those before the disaster.