• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.147-156
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• 2010

This study was conducted from April, 2002 to March 2006, using three urban streams(Gap Stream, Yudeung Stream and Daejeon Stream) in Daejeon Metropolitan City. 12,027 individual birds summed by the peak count in 126 species, 34 families, and 13 orders were observed from three stream sites. Dominant species were of Anas poecilorhyncha, Anas crecca, Columba livia, Passer montanus, and Egretta garzetta(in that order). The groups of birds were classified into six types. The most frequent group were the arbor birds(54 species), while the smallest group was the diving ducks(7 species). As for the number of individuals, the shrub bird group had 721 individuals while the dabbling ducks observed had 4,974 individuals. Regarding the distribution of birds appeareing in each stream, 14,885 individual numbers in 114 species were observed at Gap Stream, 6,642 individuals in 90 species at Yudeung Stream and 4,202 individuals in 69 species at Daejeon Stream. Various indices of the birds were analyzed with respects to the similarities between streams. Gap Stream had similar characteristics to Yudeung Stream, and the latter was similar to Daejeon Stream. However, Gap Stream and Daejeon Stream showed different characteristics. The dominance index of each section was calculated using ten dominant bird species top-down. Subsequently, the birds and their preferred environment were analyzed. The results showed that shrub birds and arbor birds preferred the upper stream of every stream, while herons and dabbling ducks inhabited the midstream. Dabbling ducks and some diving ducks appeared downstream.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.302-313
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• 2014

This study was conducted to compare the characteristics of fish distribution according to sand type stream and cobble type stream the 4 stream selected every season. The collected Korea endemic species during the survey period were 24, including Acheilognathus gracilis. Dominant species of Hongcheon stream and Muju Namdae stream was Zacco koreanus, each accounting for 39.9% and 28.4% in order, and dominant species in Yanghwa stream was Rhodeus notatus, 13.6%, and those in Gap stream was Z. platypus, by 26.0%. As a result of community analysis, dominant index was 0.27~0.63, diversity index was 1.92~2.67, evenness index was 0.6~0.79, richness index was 3.09~3.53, and dominant index was the highest in Hongcheon stream, and the indices of diversity, evenness and richness were the highest in Yanghwa stream. As a result of tolerance guild analysis, Hongcheon stream and Muju Namdae stream with a variety of substrates accounted for relatively higher rate by 50.1% and 46.4% in sensitive species respectively, and Yanghwa stream and Gap stream with greater sand substrates had 0.5% and 5.3% scarce rate of sensitive species. As a result of similarity analysis using the species, population and substrate structures of the fisheries appeared in each stream, cobble type streams such as Hongcheon stream and Muju Namdae stream were the most similar by 50.4% in species and population, 95.2% in bed structure. As a result of IBI analysis, Hongcheon stream and Muju Namdae stream appeared as 'Class A,' Yanhwa stream and Gap stream as 'Class B' and the two groups of cobble type stream and sand type stream were divided as a result of principal components analysis.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.41-58
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• 2003

This study was conducted to investigate bird community and to suggest a proper way how to manage protect bird community in Gap stream. The survey was carried out over four sections by the line transect method and point counts method from September 2001 to August 2002. Natural stream region as Gasuwon Bridge - Mannyeon Bridge are observed birds were 11 orders 29 families 67 species, Artificial stream region as Mannyeon Bridge - Daedeok Bridge are observed birds were 6 orders 10 families 30 species, Daedeok Bridge - Wonchon Bridge are 8 orders 12 families 28 species, Wonchon Bridge - Gap Stream Bridge are 8 orders 18 families 40 species. All the observed birds in artificial stream region are 8 orders 19 families 47 species. Number of species in natural stream region was higher than artificial stream region owe to a various habitat environment such as forest, cultivated land, streamside forest, sandy plain, gravelly field, reedy field etc. and can not add with the interface and the usage of the human. Number of species in artificial stream region was lower than natural stream region owe to a simple habitat environment and the water ecosystem is severed with embankment block and grass plot with the land ecosystem. The furtherance of various habitat environment which considers the ecosystem like the natural stream as the water ecosystem is joined together with the land ecosystem is desired to attract various wildbirds in Gap stream. The design is desired with the maintenance of the stream to consider the stream corridor which plays ecological important role as connect the fragment habitats.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.347-354
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• 2002

Near the Gapcheon, a new suburban city will be developed by the Ministry of Construction and Transportation, and a intracity highway will be constructed by Daejeon Metropolitan City. By these new plans, rapid disruption of environmental conditions near the Gapcheon will be anticipated. The new construction of the city and highway will raise a problem of environmental pollution and disruption of natural status of this area, and will have an adverse influence to environment of the Dunsan area and an industrial complex which are located at the downstream of the Gapcheon. This re-search was conducted on the Gapcheon area, Daejeon (Gasuwongyo to Wonchongyo) from August, 2001 to June, 2002 years. Microorganisms of Gapcheon are three forms, 17 varieties, 105 species, 58 geneva, 31 families, and totalled 125 taxa. And zooidal micro-organisms, one varieties, 16 species, 12 genera, eight families, and totalled 17 taxa. Hydrogen ion concentration of the stream is ranged from 7.10 to 9.98 with great variation, especially high below bridges of Gasuwongyo and Mannyeongyo. The clean water quality of the stream is still maintained very well due to dense distribution of diverse aqua-tic and swamp plants. Furthermore, species diversity of microorganisms in the stream does help to purify the quality of water, and to keep the health of the Gapcheon as natural. More environmentally controlled and continuous efforts to keep the Gapcheon in a natural status and to purify the quality of water should be made by Daejeon Metropolitan City Officials who ave now spending about 6G,5()0 million won for overall conservation plans of the stream (from 1999 to 2003 years).

• The Korean Journal of Mycology
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• v.45 no.2
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• pp.153-159
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• 2017

We isolated 120 strains of wild yeasts from the water and riverside soils of Daejeoncheon and Gapcheon in Daejeon, Korea. We identified Debaryomyces udenii JSF601, Kazachstania telluris JSF602, Trichosporon faecale JSF614, Candida infanticola WJSL0039, Candida palmioleophila WJSL0048, Pichia spartinae WJSL0087, and Trichosporon coprophilum WJSL0093 from Daejeoncheon, and Leucosporidium golubevii WJSL0108 and Ustilentyloma graminis WJSL0118 from Gapcheon, as newly recorded yeast strains in Korea and investigated their microbiological characteristics. All of these previously unrecorded yeasts were oval- or ellipsoidal-shaped with ascospores, except C. infanticola WJSL0039, C. palmioleophila WJSL0048, and D. udenii JSF601. L. golubevii WJSL0108 and U. graminis WJSL0118 grew in vitamin-free medium, and C. infanticola WJSL0039 was halotolerant and grew in 10% NaCl-containing YPD broth. K. telluris JSF602 and P. spartinae WJSL0087 were thermophilic yeasts, which grew at $37^{\circ}C$.

• Journal of Korea Water Resources Association
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• v.44 no.1
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• pp.65-72
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• 2011

Natural streams meander, forming pools at the outer part of bend and riffles at the crossing. Pools are deep at a lower flow velocity, and riffles are shallow at a higher flow velocity. Attentions are being paid to pool-riffle sequences in meandering streams because pool-riffle sequences tend to increase biodiversity of the stream ecosystem. This study investigates the characteristics of distribution of bed sediment particles in the upstream reach of the Gap Stream, which is a tributary of the Geum River in Korea. The upstream part of the Gap Stream, the study reach, is a gravel-bed stream, showing a pool and three riffles due to meandering. The reach also includes pools at the upstream and downstream parts of the weir. The characteristics of bed sediment particles sampled at the wetland and in the side channel are studied, revealing that the median particle diameter in the riffle is about four times larger than that in the pool. In addition, flow simulations are carried out for ordinary discharge and design flood, and such parameters important to sediment transport as velocity, shear stress, dimensionless shear stress (or Shields number), and dimensionless shear velocity are provided to see the mobility of sediment particles in the pool-riffle sequence.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.2136-2140
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• 2008

Recently environmental and ecological river management have been held in high repute, therefore it needs to river restoration and management works considering topographical shape of river. This study estimated the change of topographical shape in Gab- and Yudeung-River using time-series aerial photos. Especially, we selected location points of river facilities as weir and bridge that were built and removed and the confluence of Gab- and Yudeung-River. And we investigated the change of time-series flux and flow-direction. Also, through the estimation of sediment by river flow together, it is possible to supply decision making data that is very important to instream flow and environmental and ecological river restoration in urban stream.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.356-360
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• 2007

최근 급속한 도시화로 인한 유역내 불투수 면적의 증가는 자연유역에 비해 짧은 도달시간과 높은 첨두홍수량을 유발하여 도시홍수 피해의 원인이 되고 있다. 이러한 도시지역 하천에서의 홍수량산정은 강우-유출관계를 근간으로 하는 HEC-HMS 모형 등을 주로 활용하고 있으며, 산정된 홍수량을 토대로 각종 치수대책을 수립하여 왔다. 그러나 도시지역내의 배수체계는 하천과 연결된 우수관로를 통해 이루어지도록 구성되어 있음에도 불구하고, 우수관로 시스템의 능력평가를 하천의 홍수량과는 별개로 평가하고 있다. 즉, 하천이 외수위에 대한 영향을 고려하지 않고 배수체계의 통수능력을 평가하여 배수능이 부족한 관거를 찾는 것으로 매우 근사적이고 비합리적인 대안을 제시하고 있는 실정이다. 따라서, 본연구에서는 도시하천의 홍수량 산정에 있어 우수관로를 통한 배수체계를 고려한 도심지의 홍수량을 산정하기위하여 도시하천의 비시가지역의 홍수량은 HEC-HMS모형으로 산정하여 XP-SWMM모형의 상류경계조건으로 두고 도심지의 모든 우수관로를 하천에 연결하여 홍수량을 산정하는 방법을 제시하였으며, 대상유역은 대전광역시를 관류하는 갑천에 대하여 적용하였으며, 갑천하구에 위치한 회덕수위표의 실측유량과의 비교를 통해 그 신뢰성을 평가하였다. 본 연구의 결과는 도시홍수예방과 침수범람도 작성 등의 도시침수해석 및 치수대책수립에 기초자료로 활용할 수 있을 것으로 기대된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.262-262
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• 2023

기후변화 및 도시화에 따른 강우 패턴의 변화는 수문 변화를 야기시키며, 이에 따른 영향을 평가하고 예측하기 위해서는 수문학적 모델을 통해 정량화하는 과정이 필요하다. 그러나 기존에 개발되어 사용되고 있는 대부분의 수문학적 모델은 해외에서 개발되어 국내 유역 특성을 반영하지 못하는 한계가 있다. 이러한 한계점을 극복하기 위해서 L-THIA ACN-WQ 2016과 2018 모델이 개발되어 적용성이 평가된 바 있다. 하지만 L-THIA ACN-WQ 모델의 경우 시단위 유량 및 수질 모의가 불가능한 한계점이 있다. 소규모 유역이나 도시화된 지역에서는 하루에 여러 번의 강우 이벤트가 발생하거나 단기간에 많은 양의 강우가 발생하는 경우가 많기 때문에, 이러한 강우-유출을 평가하기 위해서는 시단위 모의가 필요하다. 본 연구에서는 시단위 유량-수질 모의가 가능한 L-THIA sub-daily WQ 모델을 개발하였으며, 갑천 유역과 복하천 유역에서 적용성을 평가하였다. L-THIA sub-daily WQ 모델은 SCS-CN 방법과 Green-Ampt 방법을 함께 고려할 수 있도록 개발하였으며, 국내의 토지이용 및 강우 특성을 고려할 수 있도록 점근 CN과 강우 계급별 EMC를 활용하였다. 갑천 유역과 복하천 유역에서 시단위 유량 예측 결과 R2는 0.61~0.69, NSE는 0.61~0.65, PBIAS는 -4.0~-7.3으로 모의된 시단위 유량이 자연현상을 잘 모의하는 것으로 나타났으며, 수질 예측 결과 T-P와 SS가 자연현상을 잘 모의하는 것으로 나타났다. 따라서, 본 연구에서 개발된 L-THIA sub-daily WQ 모델은 점오염원을 포함하고 있는 도시유역에서 비점오염원에 평가에 활용될 수 있을 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.79-79
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• 2022

수치표고모형(digital elevation model)으로부터 추출한 하천망이 실제를 제대로 대변하기 위해서는 정확한 하천시점을 지정하는 것이 필요하다. 그러나, 아직까지 범용적으로 활용할 수 있는 하천시점 결정 방법은 개발되지 못한 실정이다. 하천시점의 결정 방법에 관한 연구가 미비한 근본적인 이유는 실측을 통한 하천시점 자료가 매우 부족하기 때문이다. 또한 하천시점의 위치를 조사하였더라도 하천시점은 시간에 따라 변화할 수 있기 때문에 일회성 하천답사로 하천시점의 위치를 단정할 수 없다. 이 연구는 실측을 통해 하천시점 결정요인에 대하여 이해를 구하는 것을 목표로 한다. 무갑천을 대상으로 하여 네 차례(2월, 4월, 5월, 8월) 현장답사를 수행하여 하천시점 위치를 파악하였다. 하천시점의 개수와 위치가 변화하는 것을 관찰하였고, 2월부터 5월까지 하천시점은 상류로 팽창하는 양상을 보이다 8월에 하류방향으로 수축하는 형태를 나타냈다. 이러한 거동의 원인으로는 2월부터 5월까지유역 내 식생 발달이 비교적 적고 강수량이 증가하여 하천시점이 팽창된 것으로 파악되었며, 8월에는 강수량이 이전의 조사기간 보다 증가하였으나 식생이 활발히 발달하여 하천시점이 수축된 것으로 파악되었다.