• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.227-233
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• 2002

Recently, the water pollution of coastal sea area including harbor, bay and inland sea has been very serious and it causes u\\various environmental impacts. In this study, water flow system of Danghnag Bay, which has the narrow and long topographical characteristics with the narrow bay mouth and its flow is influenced principally by the tidal current, is investigated experimentally and numerically. In order to understand the tidal system of Danghang Bay, harmonic analysis is performed based on measured tidal range and flow velocity. In addition, numerical model for tidal exchange is developed considering conditions of Danghang Bay. Calculated results show good agreement with measurement. Lastly, based on the proposed numerical model, exchange ratio of seawater volume in Danghang Bay is predicted.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.205-218
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• 2002

Recently, the water pollution of coastal sea area including harbor, bay and inland sea has been very serious and it causes various environmental impacts. In this study, water flow system of Danghang Bay, which has the narrow and long topographical characteristics with the narrow bay mouth and its flow is influenced principally by the tidal current, is investigated experimentally and numerically. In order to understand the tidal system of Danghang Bay, harmonic analysis is performed based on measured tidal range and flow velocity In addition, numerical model for tidal exchange is developed considering conditions of Danghang Ray. Calculated results show good agreement with measurements. Lastly. based on the proposed numerical model, exchange ratio of seawater volume in Danghang Bay is predicted.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.383-392
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• 2017

In 2013, August and September(early) as summer and October and November as Fall the probe of eutrophication has been done at 22 sampling points from the entrance of Danghang Bay (Jinhae Bay) to Geosan reservoir. In Danghang Bay, total chlorophyll(TChl) concentration of summer was 3.7 times higher than that of fall, and sampling points closer to the center showed 1.8 times higher concentrations than sampling points near the fringe where fresh water encountered. Eutrophication Index(EI) exceeded 1 at all sampling points in Danghang Bay during summer and fall, and if other conditions for algae growth met there was a possibility red tide to bloom at any place. There was a tendency of EI to gradually increase moving up from the entrance of bay to the inner side during summer and fall. Especially there was a sudden increase by 2.3 times higher at sampling points of 13~22 (planned region as Madong reservoir) than at other points during fall. Nitrogen was a limiting nutrient for growth of algae during summer and fall in Danghang Bay, but phosphorus was a limiting nutrient during summer rainy season. During summer and fall, multiple linear regression analysis between EI and COD, DIN, and DIP showed a significant positive relationship and that DIP was the most effective variable. Whereas multiple linear regression analysis between TChl and COD, DIN, DIP, and DSi showed a significant positive relationship and that DIP was also the most effective variable during summer. There was no significant correlation between TChl and the other parameters during fall.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1203-1211
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• 2010

In order to study geology and sediment characteristics in Danghang Bay area, surface geological survey, SBP (sub-bottom profiler) survey, and sediment analysis were conducted. Danghang Bay area has a closing coast surrounded by land, and surface layer are covered by mud and sandy mud. Sedimentary facies of the surface layer consists of Mm and Mms facies. A SBP seismic survey shows that gas bearing sediments might be spread throughout the sediment layers, so that it seems to be hard to find acoustic basement and gas seeps are easily found throughout the survey lines. The gas trapped in the sediments may be related to the high organic contents of the sediment, and the thick mud layer may restrain the gas from releasing.

• Korean Journal of Ichthyology
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• v.31 no.2
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• pp.83-89
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• 2019

The effect of estuarine dams on fish assembladge in Danghang Bay of Goseong, Korea was determined using monthly samples collected by a beam trawl and a cast net at the natural estuaries and damed estuary from September 2011 to August 2012. In the natural estuaries without dam, salinity was relatively high showing a large diurnal change. Estuarine fishes such as striped sandgoby, Acentrogobius pflaumii and yellowfin goby, Acanthogobius flavimanus, were dominantly caught in the sea side water. In the dammed estuary, freshwater species such as pale chub, Zacco platypus and triden goby, Tridentiger brevispinis were dominanlty caught. The dam in the Danghang estuary have significant effects on the fish assemblage through aquatic environmental change such as salinity.

• 한국지구물리탐사학회:학술대회논문집
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• 2010.10a
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• pp.141-144
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• 2010

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.201-207
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• 2001

To study the distribution of organophosphorus pesticides which are extensively used for agriculture in Korea. Sea water samples were taken from 4 coastal areas during May and August of 1997 and sediment samples were collected from two coastal areas in August of 1997. These samples were analyzed using a Gas Chromatography/Nitrogen Phosphorus Detector (GC/NPD). In August the most commonly found organophosphorus pesticides in the surface waters of Kunsan area were IBP < S-Benzyl O,O-di-isopropyl phosphorothioate > $(m=432.5ng\;L^{-1})$ and EDDP < O-ethyl S,S-diphenyl phosphorodithioate > $(m=37.4ng\;L^{-1}) $ which are largely used between June and September to prevent rice blast disease. In Danghang Bay, dry fields located near the mouth of the estuary seemed to affect the concentrations of certain organophosphorus pesticides in the surface waters. Since organophosphorus pesticides applied in the watershed are rapidly decomposed while being transported along freshwater streams, watershed size is not proportional to the concentrations of these pesticides in the coastal waters. Pesticides concentrations measured in August were compared with those in May. IBP concentrations in coastal waters were about an order of magnitude higher in August than in May. Temporal and geographical distribution of individual organophosphorus pesticides is likely to be affected by types of agricultural practices in the watershed. Chloropyrifos was the most important of the organophosphorus pesticides in the sediments of the study area because of its persistent nature and high affinity to particulates.