• Journal of Korean Society of Disaster and Security
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• v.16 no.2
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• pp.57-63
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• 2023

Recently, Heavy rains and super typhoons occurred by climate change cause a lot of damage in Korea. In order to reduce such damage, various types of river maintenance projects are being promoted, but it is difficult to maintain the balance of rivers in Korea with distinct flood and dry seasons. In particular, river structures installed as a river maintenance project cause various problems such as scouring of structures and their foundations during floods and river bed changes. In order to reduce such bed scour, various vanes are installed in the bend of the river, and various bed scour reduction effects appear depending on the size, arrangement, and shape of the vanes. The vane regenerates the secondary flow in the opposite direction to the secondary flow generated by the centrifugal force, thereby reducing scour around the outer bed and promoting deposition. The theory of this study uses the governing equation applying the continuity equation that satisfies the law of conservation of mass and the momentum equation that satisfies the conservation of momentum, and measures the overall average flow velocity change rate according to design factors to investigate the effect of vanes under various conditions. Both the average and cross-sectional flow velocities decreased in both the trapezoidal vane and the square vane. In addition, vanes installed perpendicularly or inclined to the direction of river flow generate a secondary flow in the opposite direction to the secondary flow generated by centrifugal force, thereby canceling the secondary flow of centrifugal force, so the effect of the vane appears.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.124-138
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• 2003

This paper aimed to analyze the relationship between alga3 bloom patterns and hydrological, limnological data which were collected from major reservoirs in Korea for 8 years (1990${\sim}$1997). Water temperature of river-type reservoirs showed wider seasonal fluctuations than that of lake-type. pH of lake-type reservoirs was low in winter season but high in summer season. In contrast, river-type reservoirs showed high pH in spring and autumn seasons as well, and very low in summer season. COD of lake-type reservoirs and Paldang reservoir was lower (2${\sim}$3 mg/L) than that of Geumgang and Nagdonggang reservoirs (6${\sim}$9 mg/L). Dissolved oxygen (DO) of river-type reservoirs was higher than that of lake-type reservoirs. Seasonal fluctuation pattern of DO saturation in river-type reservoirs was high (80 ${\sim}$100%) and remained relatively constant whereas lake-type reservoirs showed the highest level (93%) in late spring or early summer, which gradually decreased entering winter season(46${\sim}$06%). And monthly variation of DO saturation showed inverse proportion to water volume in lake-type reservoirs. Nutrients concentration in river-type lake is higher than lake-type. Seasonal fluctuation of nutrients (T-N, T-P) in lake-type reservoirs was relatively small than that of river-type reservoirs. Annual mean N/P mass ratio of lake-type reservoirs was higher than that of river-type. Transparency tended to related with the suspended solid concentration in river-type reservoirs. Algal bloom of lake-type and river-type reservoirs occurred at any time except rainfall and winter periods. And it dominated in summer and early autumn, respectively. Algal bloom of river-type reservoirs was higher than that of lake-type. Relationship between rainfall and chlorophyll- a in lake-type reservoirs was relatively high, however river-type reservoirs showed insignificant.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.39-42
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• 2012

본 연구는 충청남도 권역내 금강본류에 유입되는 23개 소하천을 대상으로 하여 각 하천의 BOD와 T-P의 수질을 분석하였다. 효과적인 수질개선대상하천 선정을 위하여 금강수계의 목표수질과 오염물질의 그룹화를 통하여 하천을 선정하였다. 수질오염총량관리지역 목표수질을 초과한 하천으로는 정안천, 방축천, 수철천, 강경천, 석성천, 금천, 은산천, 길산천으로 해당되며 이중 강경천과, 석성천은 2009년~2011년 3개년에 걸쳐 목표수질을 초과한 것으로 나타났다. 수질오염물질의 관계에 의한 하천 그룹화 분석결과 '환경정책기본법 시행령'의 하천생활기준 BOD농도가 3.0mg/L초과, T-P농도가 0.1mg/L초과하는 Group D에 해당하는 하천으로는 강경천, 방축천, 석성천, 길산천이 해당되었으며, 우선적으로 하천수질개선이 필요하다. 목표수질과 그룹화 결과를 토대로 수질개선이 필요한 우선순위 하천으로 강경천과 석성천이 해당되며, 이 두개하천의 수질오염물질의 개선이 단기적으로 이루어져야 할 것이다.

• Korean Journal of Plant Taxonomy
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• v.46 no.3
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• pp.306-313
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• 2016

A new variety, Hosta clausa Nakai var. geumgangensis M. Kim & H. Jo, was found in Geumgang River in Korea. This variety shares several characteristics (rhizomes with underground stolon, smooth scape and purple-colored anthers) with the $re{\acute{o}}lated$ varieties H. clausa Nakai var. clausa and H. clausa var. normalis F. Maekawa. However, H. clausa var. normalis has open flowers, capsules with seeds, purple-spotted petioles, long pistils, and long narrow perianth tubes, whereas this new variety has open flowers, seedless capsules, green-colored petioles, short pistils, and short narrow perianth tubes. Hosta clausa Nakai var. clausa has closed flowers and seedless capsules.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.47-55
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• 2010

Investigations on the inundation damage and improvement measures were carried out centering around the protected horticultural complex concentrated in lowlands on the side of Geum river, in Nonsan and Buyeo, Chungnam. Most greenhouses were single-span plastic houses in this area, and tomato, strawberry and watermelon were cultivated mainly. 45.8 % of whole farmhouse were experienced in damage by inundation, and a frequency of the damage was average once in 11 years. The most urgent problem at the greenhouse culture in this area was showed in order of drainage improvement, irrigation water resources and energy saving. Consideration items in drainage improvement project for protected horticulture were showed in order of extending drain pumps, extending drain canals, using concrete flume in drain ditch. It needs to consider systematic plans that can restrain new establishment of greenhouses on the lowland paddy field in drainage area. It is difficult to remove greenhouses which are already established or prohibit cultivation. Therefore we should impose minimum duty items so that greenhouse tillers can cope with inundation. And it is thought that managing agency need to minimize farmers damage by improving drainage ability and introducing maintenance pattern that is different from rice cropping.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1298-1306
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• 2010

그 동안 우리나라 수자원 관리의 주요 목적은 치수관리에 치중되어 있었으며, 이로 인하여 하상계수가 낮아지고 유황도 개선되어 도시 지역에서의 홍수발생은 거의 일어나지 않고 있다. 그러나 최근들어 급격한 산업화와 도시의 발달로 인하여 용수수요가 급증하여, 지속적이고 안정적인 용수공급이 한계를 나타내고 있으며, 또한 수질 악화 등과 같이 환경 문제 역시 발생하고 있다. 따라서, 수자원의 관리를 위하여 갈수기의 유출 특성을 파악하는 것은 매우 중요한 요소가 되었고, 이와 같은 문제들을 해결하기 위하여 갈수량의 조사는 필수적이다. 본 연구의 목적은 갈수량의 유출 특성을 파악하기 위해 2008년 금강 수계 수위관측소 지점에 대하여 유량측정을 수행하고, 측정된 성과를 기존 수위-유량관계곡선식에 적용하여 시계열 유량 자료를 획득하는데 문제가 없는지를 검토하였으며, 하천 지형 특성의 변화 및 수위 시계열의 변화 등을 파악하여 안정적인 갈수량 자료를 생산하는데 문제가 없는지 검토하였다. 금강 본류 및 1, 2차 하천의 41개 지점에 대하여 갈수량을 조사한 결과 안정적인 유량자료를 생산하는 지점은 9개소로 전체 중에 약 22%를 차지하고 있으며, 기존 수위-유량관계곡선식과 실측값 간에 오차가 발생하는 지점은 14개소로 전체 34%를 차지하고 있다. 또한 저수위 곡선식이 개발되지 않아 유량자료를 생산하지 못하는 지점이 18개소로 전체 약 44%를 차지하고 있는 것을 알 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.373-373
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• 2023

기후변화로 인한 홍수재해는 우리나라를 포함한 모든 전세계의 이슈로 우리 앞에 다가와 있다. 수자원 인프라가 잘 구축된 우리나라와 달리 저개발국가로써 관련 인프라가 미흡한 국가의 경우대규모 예산 투입이 필요한 댐, 제방 등의 수자원 인프라 시설보다는 비구조적대책인 홍수예경보시스템 구축을 통해 재해취약지역내 우선적으로 도입하는 유역단위 비구조적인 홍수관리계획이 필요하다(김광기, 2022). 본 연구에서는 2012년 금강권역을 대상으로 구축된 홍수예측모형에 대한 개선을 위해 최신 하도자료와 시설물 현황 자료를 반영하여 수리학적 모형을 신규 구축하였다. 이를 위한 수리학적 홍수추적 모형은 FLDWAV 모형을 사용하였으며, 모형의 대상구간은 금강 상류에 위치한 용담댐에서부터 대청댐 구간까지 189.32 km 구간을 선정하였다. 대상구간은 총 773개의 하도단면으로 구성하여 대상하천에 대한 지형변화를 최대한 반영하고자 하였으며, 홍수사상은 유량이 많은 홍수사상뿐만 아니라 저유량에서도 모형의 정확도를 확보하기 위해 다양한 사상을 선정하여 보정과 검증을 실시하였다. 본 연구에서 구축된 금강의 용담댐에서 대청댐 구간에 대한 수리학적 해석모형은 다양한 홍수사상을 대상으로 모형에 대한 보정과 검증을 실시함으로써 보다 정확도 높은 홍수예경보시스템을 구축하여 하천 재해 발생을 예방하는데 활용할 수 있을 것으로 기대한다.

• Parasites, Hosts and Diseases
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• v.52 no.4
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• pp.391-397
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• 2014

We evaluated the status of Clonorchis sinensis infection and potential risk factors among residents of riverside areas (Geumgang) in Muju-gun, Jeollabuk-do (Province), Korea. From January to February 2010, a total of 349 (171 males, 178 females) stool samples were collected and examined by the formalin-ether concentration technique. Also, village residents were interviewed using questionnaires to obtain information about C. sinensis infection-related risk factors. Overall egg-positive rate of C. sinensis was 13.2%. Egg-positive rates were significantly higher in males, farmers, and residents who had lived there more than 20 years, and in residents who had eaten raw freshwater fish than in opposite groups, respectively. However, there was no significant difference between age groups, education levels, cigarette smoking, alcohol drinking, health status, past history of infection, and experience of clonorchiasis medication and examination. Logistic regression analysis was performed to determine risk factors for clonorchiasis. On univariate analysis, the odds ratios for males, farmers, those who had lived there more than 20 years, and who had eaten raw freshwater fish were 2.41, 4.44, 3.16, and 4.88 times higher than those of the opposites, respectively. On multivariate analysis, the odds ratio of residents who had eaten raw freshwater fish was 3.2-fold higher than that of those who had not. These results indicate that residents living in Muju-gun, along the Geum River, Korea, have relatively high C. sinensis egg-positive rates, and the habit of eating raw freshwater fish was the major factor for the maintenance of clonorchiasis.

• Korean Journal of Plant Taxonomy
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• v.40 no.4
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• pp.247-250
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• 2010

We report Polygonum plebeium R.Br. (Polygonaceae) as an unrecorded species from the Geumgang River, Buyeo-gun; Galmae-dong, Guri-si; the Chungju Reservoir, Jecheon-si; the Daecheong Reservoir, Okcheon-gun; and the Daecheong Reservoir, Daejeon, in Korea. It is distinguished from P. aviculare by pedicels that articulate in the middle and by its smooth and shiny achenes. The new Korean name, 'Ae-Gi-Ma-Di-Pul', is given considering the small-sized plant. In this study, a description and illustrations of the species and photos of the habitat are provided.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.237-249
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• 2020

The goal of this study was to isolate wild yeasts from waters and soils in Sangjubo of Nakdong river and Daechung dam in Daejeon city, Korea and investigate characteristics of previously unrecorded novel wild yeasts. In total, 94 strains from 39 different species of wild yeasts were isolated from 47 soils and waters samples obtained from Sangjubo in Nakdong river. Among these, 3 strains, including Rhodosporidium azoricum JSL-GRU-009, represented novel yeast strains which were previous recorded. Two hundred nine strains from 105 different species of wild yeasts were isolated from 130 soils and water samples obtained from Daechungdaegyo and Daechung dam of Shintanjin in Daejeon city, Korea. Ten strains including Bullera pseudoalba JSL-GRU-005 also represented newly recorded strains in Korea. All the 13 previously unrecorded yeasts were oval or global in shape, and nine strains, including R. azoricum JSL-GRU-009, formed ascospores. Ten strains grew well in vitamin-free medium. R. azoricum JSL-GRU-009 grew well in 20% glucose-containing yeast extract-peptone-dextrose (YPD) medium and 3 strains, including Rhodotorula oryzicola JSL-GRU-003, grew well in 5% NaCl-containing YPD medium.