• 한국해양학회지
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• v.27 no.2
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• pp.164-172
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• 1992

This study was carried out to investigate the benthic polchaete community in the southern area of Kyeonggi Bay, Korea. The species composition was examined in Asan Bay in 1985, the coastal area near Yibug in 1987, the area between Daeranjido and Asan Bay for 1988-1989, and the offshore south of Deogjeogdo in 1992. Polychaetes, the dominant faunal group occupying 57.4% in total density, comprised a total of 124 species with a mean density of 211 indiv.m/SUP -2/. The dominant polychaete was Prionospio sp. (28.8%), followed by Nephtys polybranchia (6.0%), Tharyx sp. (4.8%) Stermaspis scutata (4.4%), Lumbrineris longifolia (3.9%). The Number of species and density were higher in the coastal area near Yibug, Asan Bay and the mouth of Namyang Bay, while lower in the channels of offshore region. The cluster analysis revealed that the study area could be divided into 5 regions, which were distributed serially along the coast from Asan Bay to open sea. Each region sustained its specific Bay, Stermaspis-Heteromastus assemblage from Asan Bay to Daeranjido, Hemipodus assemblage in the channels of offshore, Lumbrineris assemblage on the coastal area o Yibug and Prionospio assemblage in the coastal area south of Yibug. Tharyx-Chone assemblage had the highest species number of 75 spp. and Prionospio assemblage had the highest density of 3,695 indiv.m/SUP -2/ due to the predominance of prionospio sp.. Hemipodus assemblage with the lowest density occupied the largest area in offshore region. The southern Kyeonggi Bay showed higher species number and lower density than the northern Kyeonggi Bay. But the dominant Polychaetes were similar between the southern Bay and the channel regions of the northern Bay.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.468-482
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• 2016

To understand variations in the seawater quality of Asan Bay over four seasons form December 2011 to February 2013, we applied two methods: an in-situ observation of water quality and a comparison study of nutrient budgets among three parts (No. 1, 2, and 3) of Asan Bay. We found a significantly high nutrient concentration in the central part of the bay (No. 2) in July 2012 both in the mass balance study and in situ observation. We presumed the source of these nutrients to be both benthic effluence from old dam reservoirs and incompletely-treated municipal waste-water. This elevated nutrient concentration in the central part of Asan Bay (No. 2) expended to off-shore area and eventually triggered an intense Chl-a concentration in Asan Bay. Based on this result, we suggest improved waste-water quality control around the drainage area of Asan Bay.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.6
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• pp.70-78
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• 1998

The changes of tidal characteristics of Kyonggi-Bay Region after the Large Reclamations in the Inchon Coastal Area have been studied by the numerical modelling. The constructions of Inchon International Airport and Sihwa Seadike were considered as the main reclaimation projects in this region. A two dimensional hydrodynamic model was used for this study, and it was composed in relatively high resolution with curvilinear orthogonal coordinate. As the results, at the Inchon harbor and Palmido, where a deep channel is developed, the semi tidal ranges(Z$_0$) were decreased in 8 cm after the two reclamations. However, the Z$_0$ values in the outside of the deep channel were decreased only in 2~4 cm, so that the tidal changes in the deep channel were greater than in the outside of it. After the reclamations, the maxmum velocity was increased 17% at the Inchon harbor, however it was decreased from 1. 55 m/s to 1.10 m/s at the Palmido. This is because the available area in which the stream may spread out was largely reduced after the reclamations. An Asan-bay region, the Z$_0$ was decreased in 5 cm at the Punyang-man and Asan-man stations located after the reclamations in Inchon coastal area. However the changes of Z$_0$ were very little at the outside of Asan-bay. In Asan-bay, the current velocity and direction were little influenced by the reclamations in Inchon coastal area.

• Economic and Environmental Geology
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• v.11 no.2
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• pp.81-88
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• 1978

Nearly 300 bottom sediments and 20 box-cores were sampled from the Asan bay. The central portion of the Asan bay is covered by sand, slightly gravelly sand and gravelly muddy sand. Between the central and marginal zones gravelly mud and slightly gravelly sandy mud are characteristically distributed. The gravel population in the sediments seems to be originated from the rocky bottom on the area near the bay because the gravel is angular and composed of the schist and gneiss. The quartz/feldspar ratio is about 3/2. It is considered to be that the amount of feldspar in this bay is much higher than that of any other areas in the Yellow Sea. This is considerd to be comparatively short distance of transport ion of these sediment from the provenance.

• Journal of Environmental Impact Assessment
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• v.4 no.1
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• pp.47-57
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• 1995

This study analyzes the problems of environmental laws, development planning laws, Metropolitan Area Development Planning(MADP), and the level of environmental pollution at Pusan and Asan-Bay Metropolitan Area where MADP will be realized in the near future. In order to prevent the environmental pollution by realization of MADP, Environmental Impact Assessment Act and environmental impact assessment systems in Korea should be revised so as to reflect the followings. First, the impact of national landuse planning change on the environment should be considered at the beginning of environmental impact assessment procedures. Second, the overlapping and greater impact of many projects, whose part is the subject of environmental impact assessment, upon surrounding metropolitan area should be simultaneously evaluated and the environmental pollution protection and abatement alternatives must be made according to the above impact of the projects. Thirdly, total effluent regulation of water pollution, air pollution and solid wastes should be enforced based on the self-purification of the metropolitan area environment.

• Journal of Environmental Impact Assessment
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• v.4 no.3
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• pp.63-71
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• 1995

This study analyzes the problems of environmental laws, development planning laws, Metropolitan Area Development Planning (MADP), and the level of environmental pollution at Asan-bay metropolitan area, where MADP will be realized in the near future. In order to prevent environmental pollution by the implementation of MADP, the Environmental Impact Assessment (EIA) Act and EIA systems in Korea should be revised so as to reflect the followings. First, the impact of national landuse planning changes on the environment should be considered at the beginning of the EIA procedures. Second, the overlapping and greater impact of many projects upon surrounding metropolitan areas should be simultaneously evaluated, though each project is the subject of EIA, and the environmental pollution protection and abatement alternatives must be made in accordance with the above impact of the projects. Thirdly, total effluent regulation of water pollution, air pollution and solid wastes should be enforced based on the self-purification of the metropolitan area environment.

• Ocean and Polar Research
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• v.32 no.3
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• pp.203-212
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• 2010

Distribution of organophosphorous pesticides (OPs) was studied from February to September 2008 in the seawater of Asan Bay, Korea. Among the 29 types of OPs detected during the study period, IBP(S-benzyl O,O-diisopropyl phosphorothioate), ranging from <1 ng/l to 377 ng/l, was the most abundant. Other commonly observed OPs concentrations in the study area included diazinon (Diethyl 2-isopropyl-4-methyl-6-pyrimidinyl phosphorothionate; <1~307 ng/l), azinphos ethyl (3,4-Dihydro-4-oxo-3-benzotriazinylmethyl O,O-diethyl phosphorodithioate; <1~1997 ng/l), malathion (1,2-Di(ethoxycarbonyl)ethyl O,Odimethyl phosphordithioates; <1~3013 ng/l), demeton-O (Diethyl 2-(ethylthio)ethyl phosphorothionate; <1~2403 ng/l), and DDVP (2,2-dichlorovinyl dimethyl phosphate; <1~283 ng/l). Seasonal distribution of OPs in seawater is dependent on the OP application period. In August, OPs concentrations were generally decreased with the increased salinity of seawater, implying progressive dilution of pesticides in the estuarine system. OPs were deposited into Asan Bay from Asan and Sabkyo Lakes as well as surrounding tributaries. Ten OPs, including diazinon, were detected in the suspended particles of Asan Bay.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.671-681
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• 2014

The distribution and abundance of coastal fish species in Asan Bay, Korea, were estimated from hydroacoustic survey and net catches. Acoustic data were collected with 38 and 200 kHz from July to October of 2012, and converted to the nautical area scattering coefficient (NASC, $m^2/mile^2$) for $0.25n{\cdot}mile$ along ten transects. Japanese anchovy Engraulis japonicus was the dominant specie in the net catches. The virtual echogram technique was used to distinguish E. japonicus from other species based on the differences in the mean volume backscattering strength (${\Delta}MVBS$) at 38 and 200 kHz. Engraulis japonicus and other fishes are mainly distributed in the center channel and outer part of Asan Bay. E. japonicus tends to move from inner to outer Asan Bay in summer and fall. From NASC data, the target strength and length-weight function of E. japonicus and other fishes were used to estimate the E. japonicus stock at 24.1-93.3 tons, and other fish at 40.6-88.4 tons from July to October 2012. The estimated anchovy biomass compared well with the cumulative catch weight from stow net catches. The hydroacoustic method offers an approach to understanding spatial/temporal structure and estimating the biomass of fish aggregations in coastal areas.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.1
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• pp.1-9
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• 2009

Distribution characteristics of organophosphorous pesticides (OPs) were studied over the period from May to September, 2006 in Asan Bay, Korea. During the study period, 28 kinds of organophosphorous pesticides dissolved in surface water and adsorbed on suspended particle were measured. In the surface water, the dominant OPs were IBP and DDVP, and the concentration were in the ranges from not detected to 2014.4 ng/L for IBP and 3.2 to 696.3 ng/L for DDVP. The highest concentrations of OPs in the surface waters in Asan Bay appeared in July and August showing that seasonal distributions of OPs depend on application time and precipitation. The concentrations of OPs generally decreased with the increase of distance from the mouth of Asan Bay, implying progressive dilution of pesticides in the estuarine system. OPs residue in Asan Bay was relatively higher than in other area of Korea. The concentrations of the observed OPs concentrations did not exceed the seawater quality standard of Korea. DDVP, IBP, Diazinon, Phorate, Azinphos ethyl and Chlorfenvinfos had higher adsorption capacity onto suspended particle than the other OPs. In the study area, adsorption coefficients $(K_d)$ of OPs were closely related to the Log $K_ow$ of each compound.

• Korean Journal of Heritage: History & Science
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• v.42 no.3
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• pp.26-47
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• 2009

This study examined dwelling site from among the sites of the Neolithic age found in the Asan Bay(牙山灣) area, and the temporal-spatial location and meaning of the dwelling site (settlement). The majority of the settlements in the area are of a square style but some coexist with rectangular-style settlements, which is noteworthy. The dwelling sites of the Neolithic age found in Asan Bay area are mostly located in a ridge of hilly areas, divided into gentle, low areas (20~50 meters above sea level) and relatively high areas (50~80 meters above the sea level). Although location strongly corresponded to the residents' subsistence and the technical levels within the culture, it likely was greatly affected by natural environment where they lived, as well. In examining radiocarbon dating results and the excavated artifacts, the settlements found in Asan Bay were determined to belong to the period II(3,500~3,000 B.C.) stated in the Relative Chronological table of Dwelling sites in the Neolithic age, written by the author. Said Dwelling sites are proven to have a close relationship with those found on the coast of Gyeonggi Province(京畿道) and in the Geum River(錦江) valley. This is deemed to be the result of expansion and interchange between Gyeonggi Province(京畿道) group and Geum River(錦江) valley group, who constituted the large settlements. Additionally, the Daecheon-ri type dwelling sites in the Geum River valley were verified to be the result of exchange, and spread to the Asan Bay area in the same era. Two forms of Dwelling sites coexisted dynamically in the Asan Bay area around 3,500 B.C. Such a phenomenon resulted primarily from the expansion of the dwelling site due to the introduction of primitive agriculture, as well as environmental (temperature), biological and social changes at those times.