• Economic and Environmental Geology
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• v.42 no.4
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• pp.315-333
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• 2009

In this study, the hydrochemical and the isotopic characteristics of major streams in the Daejeon area were investigated during rainy and dry seasons. The stream water shows the electrical conductivity of the range of $37{\sim}527{\mu}s$/cm, and pH $6.21{\sim}9.83$. The chemical composition of stream waters can be grouped as three types: the upper streams of Ca(Mg)-$HCO_3$ type, Ca(Mg)-$SO_4(Cl)$ type of middle streams flowing through urban area, and Na(Ca)-$HCO_3$(Cl, $SO_4$) type of the down streams. Based on in-situ investigation, the high pH of stream waters flowing through urban area is likely to be caused by the inflow of a synthetic detergent discharging from the apartment complex. The electrical conductivity of stream waters at a dry season is higher than those of at a rainy season. We suggest that the hydro-chemical composition of stream waters in the Daejeon area was affected by the discharging water from the sewage treatment facilities and anthropogenic contaminants as well as the interaction with soil and rocks. ${\delta}D$ and ${\delta}^{18}O$ values of the stream waters show the relationship of ${\delta}D=6.45{\delta}^{18}O-7.4$, which is plotted at a lower area than global meteoric water line(GMWL) of Craig(1961). It is likely that this isotopic range results from the evaporation effect of stram waters and the change of an air mass. The isotope value shows an increasing trend from upper stream to lower stream, that reflects the isotopic altitude effect. The relationship between ${\delta}^{13}C$ and $EpCO_2$ indicates that the carbon as bicarbonate in stream water is mainly originated from $CO_2$ in the air and organic materials. The increasing trend of ${\delta}^{13}C$ value from upper stream waters to lower stream waters can be attributed to the following reasons: (1) an increasing dissolution of $CO_2$ gas from a contaminated air in downtown area of the Daejeon, and (2) the increment of an inorganic carbon of groundwater inflowed into stream by base flow. Based on the relationship between ${\delta}^{34}S$ and $SO_4$ of stream waters, the stream waters can be divided into four groups. $SO_4$ content increases as a following order: upper and middle Gab stream${\delta}^{34}S$ value decreases as above order. ${\delta}^{34}S$ value indicates that sulfur of stream waters is mainly originated from atmosphere, and is additionally supplied by pyrite source according to the increase of sulfate content. The sulfur isotope analysis of a synthetic detergent and sewage water as a potential source of the sulfur in stream waters is furtherly needed.

• Journal of the Korean housing association
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• v.18 no.4
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• pp.69-78
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• 2007

This study is to describe the changes of spatial structure of Korean traditional housing in urban context with the following preconditions. Firstly, Chosun Hanyang's urban housing should be classified as it's own type. Secondly, Chosun's traditional housing accomplishes a complete urban housing type in Japanese colonial period through the stream of time. And the purpose of this study is as followings. First is to find out the process of changes of urban housing in urban context from the latter period of Chosun Dynasty to 1960's. Second is to find out the origin of spatial structure of urban house which is being kept throughout the above changes. Third is to find out the unique characteristics of urban house and the fundamental differences with folk houses in province.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.129-141
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• 2008

This study analyzed and assessed the water quality of a small urban stream in the apartment complex of Yewol-Dong, Buchun-Si at Korea. The flows in the stream due to the interceptions of sewage and normal flow are usually low and the water quality and offensive odor problems by inflows of the sewage and other pollutants are occurred in the study area. Therefore we intended to monitor and identify the water quality conditions. Based on this, we simulated water quality using QUAL2E model and investigated water quality characteristics for the future. As the results, we found that the water quality depended on the inflows of point and non-point sources and so it is important to maintain instream flow for improvement of water quality problem and to intercept point and non-point sources in this study area.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.139-145
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• 2010

Recently, close-to-nature stream improvement works have been carried out in urban streams, where eco-friendly bank revetment methods have been adopted. These bank revetment methods are vulnerable to be damaged or washed away by floods compared to the traditional methods which use concrete materials. Damage analysis methods on the urban streams by the floods of severe rain storm are presented. The analysis methods are the graph-using method and the grid method, which are derived from the survey results at Gwangju stream. Damage analysis grid which is intersected velocity grid and material strength grid is the highest correlation with the damage survey grid. The biggest damage on the bank revetments have been occurred around the crossing structures. Big damages have also been occurred in the connection of low water revetment and the terrace land, and around the structures in the terrace land of the stream.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.522-525
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• 2003

Mine waters, surface waters and groundwaters were sampled around seven Au-Ag mine areas (Dongil, Okdong, Dongjung, Songcheon, Ssangjeon, Dogok and Gubong Au-Ag mines). The main contamination sources of As in these abandoned Au-Ag mines can be suggested as mine tailings and waste rocks including the sulfide gangue minerals (arsenopyrite). The relatively high concentration of As in mine waters was shown in the Dongil (524 ${\mu}g/L$) and the Dogok (56 ${\mu}g/L$) mine areas. Arsenic concentrations in stream waters from the Dongil ($0.9\~118{\mu}g/L$), the Songchon ($0.8\~63{\mu}g/L$), the Ssangjeon ($1.6\~109{\mu}g/L$) and the Gubong ($3.6\~63{\mu}g/L$) mine areas exceeded the permissible level for stream water in Korea. Groundwaters collected from the Dongil ($0.9\~64{\mu}g/L$ ), the Okdong ($0.2\~69{\mu}g/L$) and the Gubong ($0.5\~101{\mu}g/L$) mine areas contained high As concentration to cause the arsenicosis in these areas. In As speciation, the concentration ratios of As(III) to As(total) present up to $75\%$ and $100\%$ in stream waters from the Okdong and the Songcheon mines, and $70\%$ in groundwaters from the Okdong and the Dongjung mines. Arsenic concentration decreases downstream from the tailing dump correlatively with pH and Fe concentration. Highly elevated As concentrations are found in the dry season (such as April and March) than in the wet season (September) due to the dilution effect by heavy rain during summer in stream waters from the Dongil and the Songcheon mine areas.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.34-41
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• 2012

The variation of dissolved oxygen (DO) was monitored with high frequency by an automatic data-logging sensor in a eutrophic urban stream (the Anyang Stream) located in a metropolitan area of Seoul, South Korea. In general, DO showed the diel variation of increase in daytime and decrease at night, implying that primary production is a major mechanism of oxygen supply in this ecosystem. The fluctuation of oxygen was determined by rainfall. DO depletion was most obvious after a rainfall resulting in an anoxic condition for a day, which is thought to be caused by scouring of periphyton and organic ooze at the stream bottom. Seasonally DO was higher in winter and frequently depleted in warm seasons. DO depletion was often at a dangerous level for fish survival. Fish survey showed that little fish was living at the study site and oxygen depletion may be the major stress factor for aquatic animals. From the results it can be suggested that a high frequency monitoring of oxygen should be established for the proper assessment of aquatic habitats and better management strategy.

• Water Engineering Research
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• v.6 no.4
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• pp.189-195
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1371-1372
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• 2005

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.43-55
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• 2013

The purpose of this study is to propose a plan that properly organizes urban close-to-nature streams by evaluating the city park functions, ecological functions and landscape functions required for urban stream and setting up space function suitable for the space. The site of this study is Hongjecheon located in Seodaemun gu of Seoul City, whose length of channel spans 6.12km in total. The plan for the construction of close-to-nature streams had been established from late 2003, and the construction was completed. Evaluation Categories and indications were deduced from 4 stages. First, based on theoretical examination, we made a list of stream and park evaluation categories and added Category about Characteristic of urban streams. Next, we set Final Evaluation Categories and indications through the process of goal-relevance, indication verification, merging similar category. Final Evaluation Categories were deduced such as usage demand, usability(city park functions), biodiversity, inhabitation potential, rarity(ecological functions), historical cultural elements, and landscape Quality(landscape functions). As a result of allotting space functions, zones 1 through 4, got high grades at usage demand, was classified as a civic resort district; zones 5 through 6, close to major green area and remained original landscape, as ecological conservation and restoration district; zones 7 through 8, get high grades at usage demand and usability, as environmentally-friendly use district; and zones 9 through 10, many historical cultural elements and view points, and high green possession rate, as stream scenic district. In addition, detail space function and construction plan for each zones were proposed. As a result of this study, proposed space function assignment considering natural characteristics, humanities and social characteristics and landscape characteristics and is expected to be utilized at reasonable spatial planning considering various functions required for urban stream.

• Journal of Environmental Science International
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• v.14 no.8
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• pp.739-748
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• 2005

The purpose of this study is to analyze seasonal changes in structure and landscape of Gongji stream corridor in Chuncheon, and to suggest some guidelines to contribute to creating a desirable close-to- nature stream. The study seasonally surveyed floodplain and revetment conditions, channel micro-topography, streamflow level and velocity, and vegetational cover. Flooding, water level, and vegetation were major factors of affecting seasonal changes in streambed structure and stream landscape. Small sand bars and islands were considerably disturbed by flooding and water level change. However, large islands and sand bars in the upper and middle section of the study stream remained or reappeared even after flooding. Flooding also tended to repeat channel sedimentation at the same spot. Controlling water volume of the Euiam Lake, which is adjacent to the study stream, caused higher water level downstream in the dry seasons. The majority of vegetation in sand bars and islands was washed away by the floods. Vehicle passing, crop cultivation, and ball game were other elements which disturbed vegetation in the floodplain. Creating a close-to-nature stream should reflect micro-topographical changes of channel by flooding, prevent improper vehicle entry and human use, and remove concrete material in the revetment and floodplain.