The article published from the Oceanographic Society of Japan criticized some prediction and evaluation methodologies applied to Environment Impact Assessment (EIA) for the construction of a manmade island in the Ise Bay. Understanding of the currently available prediction-technologies is needed for the suitable choice of the evaluation methods. Social requirements for the prediction-technologies often result in the use of an over-detailed, unnecessary-complicated and low-accurate model. Even a succeeded model for predicting a shallow water environment cannot ensure the following success in the use for the other coastal environments due to the variability of coastal nature and impacts on them.
　In this paper, we pointed out the importance of the structural understanding of hydraulics and environmental systems in inner part of bays. Moreover, we discussed the use of state-of-the-art prediction models for anticipative impacts including changes in topology, grain size, and water quality by sediment-water interaction
s. Our conclusion was as follows : (1) one-line models are still superior to 3-D models for a long-term prediction of topology. (2) The hydrodynamic model, which can estimate the shear stress at sediment surface caused simultaneously by tidal currents and waves, would be a key solution for predicting the granulometric changes occurred in shallow water environments. (3) The water column depth of predicting sites is important for the determination of necessity of the model considering the effect of sediments on nutrient concen trations in the overlying water.