The real-time data of the continuous water quality monitoring station at the Pyeongchang river was analyzed separately during the rainy period and non-rainy period. Total organic carbon data observed during the rainy period showed a greater mean value, maximum value and standard deviation than the data observed during the non-rainy period. Dissolved oxygen values during the rainy period were lower than those observed during the non-rainy period. It was analyzed that the discharge due to rain fall from the basin affects the change of the water quality. A model for the forecasting of water quality was constructed and applied using the neural network model and the adaptive neuro-fuzzy inference system. Regarding the models of levenberg-marquardt neural network, modular neural network and adaptive neuro-fuzzy inference system, all three models showed good results for the simulation of total organic carbon. The levenberg-marquardt neural network and modular neural network models showed better results than the adaptive neuro-fuzzy inference system model in the forecasting of dissolved oxygen. The modular neural network model, which was applied with the qualitative data of time in addition to quantitative data, showed the least error.

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The purpose of this study is to estimate the wave height located at the front face of the offshore refracted breakwater when the trench is dredged in the exterior region of the breakwater at various depths. The problems that arise with regard to the different obliquely incident wave field involve having two-dimensional planes and having the configuration of the trench region designated by a single horizontal rectangular system. The numerical approach involves applying the Green function based on the boundary integral approach. The results of the present numerical works are illustrated. The ratio of the wave height reduction at the front face of the refracted breakwater is shown to be more than 25% due to the trench's effect on the seabed. The corner of the refracted breakwater is where the wave energy is concentrated, and through utilizing the trench, the wave energy can be subdued to reduce the damage on the breakwater. The trench brings about a reduction in wave amplitude and wave energy in, around, and directly downstream of the trench.