• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.11-11
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• 2017

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.4
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• pp.37-44
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• 2003

In order to evaluate the contribution of MMSTP operation to the improvement of marine water quality of Mokpo harbour and to estimate the change of pollution loads flowing into Mokpo harbour after the operation of Mokpo Municipal Sewage Treatment Plant (MMSTP), the pollution loads flowing into Mokpo harbour from land in dry weather were surveyed and estimated on the bases of the seasonal flow rates and the seasonal water qualities of streams and effluents located around Mokpo harbour from summer, 1997 to spring, 1998 before the operation of MMSTP, and the pollution loads of the inflow and the effluent of MMSTP were also surveyed and estimated from winter, 1998 to spring, 1999 after the operation of MMSTP. The treatment rates of MMSTP were shown to be about 49% in COD, 76% in TSS, 79% in VSS, 3% in T-N, 7% in DIP, 29% In T-P and -32% in DIN. The change rates of pollution loads flowing into the inner harbour of Mokpo due to the operation of MMSTP were shown to be about 56% in COD, 78% in TSS, 84% in VSS, 45% in DIN, 22% in T-N, 34% in T-P and -14% in DIP The contribution rates of MMSTP operation to the reduction of total pollution loads flowing into the entire Mokpo harbour were found to be about 3% in COD, 3% in TSS, 5% in VSS, 1% in DIP, 3% in T-P and -1% in DIN.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.1
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• pp.11-20
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• 2003

The pollution loads flowing into Mokpo harbour from land in dry case were estimated on the bases of the seasonal flow rates and the seasonal water qualities of streams and effluents located around Mokpo harbour. Average daily amount of fresh water Stowing into Mokpo harbour obtained by the inflow rate data of 4 seasons was found to be about 5.5×10/sup 6/㎥/day and annual inflow rate to be about 2×10/sup 9/㎥/year. The seasonal flow rates of effluents iron Yongsan lake were above 90％ of total flow rates of all inflows in 4 seasons. The concentrations of COD, TSS, TIN and TP at 9 inflow stations Iron streams and effluents in 4 seasons were shown to be in the ranges of 2.87~42.69㎎/ℓ, 3.65~1080.32㎎/ℓ, 0.083~89.744㎎/ℓ and 0.028~6.926㎎/ℓ, respectively. The average loads of COD, TSS, TIN and TP into Mokpo harbour estimated by the data of 4 seasons were found to be about 37 ton/day, 64 ton/day, 13 ton/day and 1.2 ton/day, respectively. The loads of COD, TSS, TIN and TP into Mokpo harbour in summer were shown to be about 82 ton/day, 159 ton/day, 14 ton/day and 2 ton/day, respectively. The main source of pollution loads into Mokpo harbour was found to be the effluent of Yongsan lake.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.2
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• pp.49-59
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• 2000

Wave distribution in Jangjeon Harbour is numerically simulated for an optimum design of the harbour facilities. A deep-water design wave is estimated based on stochastic extreme wave analysis of wind data in the vicinity of the harbour, and it is applied to the boundary condition at open sea. Boussinesq wave theory that includes effects of frequency dispersion and nonlinearity is employed for the wave simulation. The porosity and sponge layer are adapted at beach to depict partial reflection and complete absorption of waves, respectively. The design wave for breakwater is computed in global domain with coarse grids and the wave distribution inside of wharf is simulated in local domain with fine grids.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1323-1336
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• 2010

This study was carried out to determine marine environments and phytoplankton community around Mokpo harbour on March to November during the period of 2004-2009. The remarkable fluctuations of marine environments were shown around Mokpo harbour depending on monthly and yearly. Among seasons, summer was a great that was associated with extremely releasing the freshwater from Youngsan River Weir, contributing to effect the fluctuations of water quality. Nevertheless of monthly and yearly, the molecular ratio of N:P was always shown in above 16 that was mainly attributed to freshwater discharge on March to November. This indicates that phosphorus playes an important role in limiting factor as growth in phytoplankton. During this study, Skeletonema costatum was found to be richer than the other groups of diatoms in terms of abundance and species number. Mokpo harbour, with the presence of a narrow avenue for exchange with offshore waters, has limited growth in phytoplankton, but this species is able to well adapt and fast grow under even high level of suspended solid and low intensity of light compared with other species. The discharge of freshwater is associated with significantly fluctuation of marine environments in this region, but it does not affect the quantitative and qualitative distribution of phytoplankton. It is necessary to persistently monitor based on water quality and phytoplankton community.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.141-150
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• 2016

Most previous studies on dinoflagellates in Korean coastal areas were conducted without morphological descriptions and illustrations of the observed dinoflagellates. This indicates that the species and diversity of dinoflagellates may have been respectively misidentified and underestimated in the past, probably due to cell shrinkage, distortion and loss caused by sample fixation. This study provides information on the morphological observations of four dinoflagellate orders (Prorocentrales, Dinophysiales, Gonyaulacales and Gymnodiniales) from Jangmok Harbour in Jinhae Bay, Korea. The unfixed samples were collected weekly from December 2013 to February 2015. A total of 13 genera and 30 species were identified using light and scanning electron microscopy, although some samples were not clarified at the species level. Harmful dinoflagellates, Prorocentrum donghaiense, Tripos furca, Alexandrium affine, A. fundyense, Akashiwo sanguinea and Cochlodinium polykrikoides, were identified based on the morphological observations. The results also reflect the occurrence and identification of dinoflagellates that had not been previously recorded in Jangmok Harbour.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.4
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• pp.439-451
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• 1994

A numerical model for harbour oscillation is presented by use of Galerkin finite element method. The governing equation is used by the modified mild slope equation derived from Chen (1986) in which bottom friction is incorporated. Since the existing absorbing boundary condition. however. is shown to be incorrect correct boundary condition and forcing term due to an incident plane wave are rederived. Computation results for a rectangular harbour are shown in comparison with both laboratory data and existing numerical results. After the values of friction factor (f) and reflection coefficient (K$_{r}$) are discussed, the set (K$_{r}$=0, 94, f=0) is found to be best fitted to the laboratory data of the rectangular harbour.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.57-65
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• 1999

The in situ observations and the seawater analyses were conducted at all seasons from July 1996 to April 1999 for the purpose of describing the characteristics of seasonal variations of water quality in Mokpo harbour, Korea. Vertical stratification started to be formed in water column in spring, developed in summer and disappeared in fall. In summer, vertical density distribution of water column was found to be in stable structure with lower temperature and higher salinity of bottom water, and the vertical mixing of water between surface and bottom layers was restricted. In winter, however, surface water was found to be similar to bottom water in temperature and salinity, and water column was in unstable structure and in well-mixed condition between surface and bottom waters. The saturation percentage of dissolved oxygen(DO) in bottom water of inner part of Mokpo harbour at all seasons was shown to be decreased to the third grade or under the third grade of Korean standards of seawater quality. In particular, dissolved oxygen was oversaturated in surface water and undersaturated in bottom water in summer, due to stratification and organic pollution. The difference of DO concentration between surface and bottom waters was found to be greater in spring and summer than in fall and winter, due to stratification and photosynthesis of phytoplankton. The concentrations of chemical oxygen demand(COD) over the entire waters of Mokpo harbour were found to fluctuate from below the third grade to the first grade of Korean standards through all seasons and COD concentrations of same seasons were shown to be different year after year. In particular, in view of COD, the annual average seawater quality of Mokpo harbour was evaluated to be in third grade of Korean standards, due to organic pollution. The average COD of surface water was greater than that of bottom water in spring and summer, due to the autochthonous COD caused by production of phytoplankton in surface waters, while the average COD of surface water was similar to that of bottom water in fall and winter, due to the vertical mixing of water between surface and bottom layers.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.303-312
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• 1998

It is necessary to quantitatively asses the influence of tidal currents to analysis the coastal current patterns before or after constructing offshore structures like as breakwaters. This assesment can be made through the use of simulation models designed to reproduce the water movements of the area. And it is very important to predict a phenomenon of pollutant dispersion in the area. In this study, in order to predict the changes of sea water quality for the port development plan, Ilgwang harbour, located at the east coast of Pusan, the numerical computations were carried out. The flow patterns were investigated before and after the development of the harbour bay and coastal area connected on it. The computational models are an extension of earlier work on the flow which used the ADI Method (Alternating Direction Implicit Method) in appling to Osaka Bay by KANEKO et al. The transport of pollutant constituents depends upon the currental characteristics of the water-transporting medium. In the currental flow model, water velocities and water levels are computed throughout the regions of it. These value are then used in the mass-balance equation to obtain the pollutant-constituent transport. As a result of this research, the present water quality of Ilgwang harbour and the coastal areas connected on it was proved out some good condition. The changes of sea water quality due to the port development plan of the Ilgwang habour bay and the coastal area were not large compared with the present condition, but it will be likely able to get worse by increasing the semi-enclosed areas in the harbour bay. In order to improve the water quality of the area after development, the method to activate tidal exchange in the area can be needed, as a mitigation technique.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.367-373
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• 2021

In this study, deep learning model was set up to predict the wave heights inside a harbour. Various machine learning techniques were applied to the model in consideration of the transformation characteristics of offshore waves while propagating into the harbour. Pohang New Port was selected for model application, which had a serious problem of unloading due to swell and has lots of available wave data. Wave height, wave period, and wave direction at offshore sites and wave heights inside the harbour were used for the model input and output, respectively, and then the model was trained using deep learning method. By considering the correlation between the time series wave data of offshore and inside the harbour, the data set was separated into prevailing wave directions as a pre-processing method. As a result, It was confirmed that accuracy and stability of the model prediction are considerably increased.