• Journal of Environmental Policy
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• 제8권3호
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• pp.181-206
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• 2009

The purpose of this paper is to analyze economic adequacy by estimating the benefit-cost for bird eco-park, eco-center, eco-river, and eco-waterway, which will be built in the new town of Kimpoo, Yangchon. This paper attempts an economic analysis for the development of an eco-friendly new town. The rates of B/C (benefit-cost) in all scenarios are over one. Especially, the B/C rate of the eco-center is the most efficient of the four eco-facilities by 5.02 - 3.75. In addition, the construction costs of the five eco-facilities are assumed to be 50 percent higher, though their economic soundness is maintained. This paper implies that providing ecological variety is one of the core components in constructing housing complexes and suggests that the construction of housing be harmonized with zero-carbon and energy efficient methods.

• Korean Journal of Environment and Ecology
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• 제32권2호
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• pp.154-164
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• 2018

We investigated the ichthyofauna and fish community structure of the Mudeungsan National Park, Korea from 2014 to 2016 to prepare a conservation plan. We collected 21 species of 6 families collected from 8 survey stations through skimming nets and cast nets during the period. The dominant and subdominant species were Zacco temminckii (43.0%) and Rhynchocypris oxycephalus (15.1%), respectively. The other abundant species were Z. platypus (11.2%), Pungtungia herzi (10.1%), Squalidus gracilis majimae (8.9%), and Z. koreanus (4.5%). Among the fish collection, 13 species (61.9%) were Korean endemic species, but, endangered species and exotic species were not found. Similarity indices based on species composition and abundance showed the clear division of the fish community into two river systems (Yongsan River drainage system (St. 1-7) and Seomjin River drainage system (St. 8)). The Youngsan River system was further divided into the uppermost (St. 1, 2, 4, 6, and 7) and the upper-middle (St. 3 and 5) regions. The number of species appearing in a year was similar at 19 to 20 throughout the survey period. However, the individual number of fish in 2015 (2,670) was 20% less than that of 2014 (3,366) and 2016 (3,429), respectively. The probable reason for this decline is the rapid decline of stream level in 2015 compared to the other years. During the survey period, river works were undergoing at 3 out of 8 stations, having created disturbance in fish habitat and especially impacted on benthic fishes.

• Journal of Wetlands Research
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• 제10권1호
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• pp.39-47
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• 2008

An eco-washland is increasingly getting attentions as a new alternative plan for management of water resources because of role as flooding control and ecological park without social and ecological side effects. However, there is a lack of study regarding technological development and ecological guidelines to create eco-washland. This study was carried out to suggest ecological guidelines necessary for engineering process to create eco-washland. A study site was the lower reach of Seokjang stream connecting to Yimjin river, a candidate of new eco-washland, and Kumsa area in Namhan river was selected as a reference site. The analysis of ecological characteristics focused on vegetation, fishes, and birds. Major vegetation communities, composed of dominant species such as Salix koreensis, Salix gracylistyla, Miscanthus sacchariflorus, Phragmites communis, etc., formed physical conditions along with other land uses including open water, sandbar, cultivated land, etc. Dominant species of fishes were some species belonging to Cyprinidae and Acheilognathinae, and in case of birds Anser albifrons, Anas platyrhychos, Anas poecilorhyncha belonging to waterbirds and Paradoxornis webbinanus dependent to forest edge were dominantly distributed. The results showed that complex wetland types associated with partially deep water and upland was the optimal eco-hydrological condition of washland. Cyprinidae and Acheilognathinae in case of fish and Egretta spp. (spring season) and Anas spp. (winter season) in case of bird were selected as target species for the these wetland types. Finally, a detail planning criteria to create habitats of these target species were discussed in terms of spawning, breeding, feeding, resting, refuge, nesting, etc.

• Animal Systematics, Evolution and Diversity
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• 제34권4호
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• pp.194-198
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• 2018

The genus Prionchulus Cobb, 1916 represents a group of predaceous nematodes belonging to the family Mononchidae Chitwood, 1937, and is found worldwide. However, only five species have been reported thus far from Korea. Prionchulus oleksandri Winiszewska and Susulovsky, 2003 is reported for the first time from Korea, from sediments collected from the Nakdong River. This species is distinguished from other Prionchulus species by its truncated lip region with small cephalic papillae and refringens vaginae. In this study, morphological characters(detailed morphometrics) of P. oleksandri are described and illustrated using optical microscopy. DNA barcode sequence information (the D2-D3 region of 28S rDNA, 18S rDNA, and internal transcribed spacer rDNA) is also provided for the molecular identification of the species.

• Korean Journal of Ichthyology
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• 제34권4호
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• pp.270-276
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• 2022

In 2020 and 2022, the habitat of brown trout (Salmo trutta) was investigated in the Soyanggang River in Chuncheon, Gangwon province. As a result of the fish survey, A total of 43 individuals brown trout were identified. The total length of brown trout was widely confirmed from 60 cm or more to less than 10 cm. In January 2020, sperm release and spawn were observed in male and female confirmed at the St. 1. Brown trout were identified stably settled in the Soyanggang River and continues to live. In addition, benthic macroinvertebrates that can act as food sources of brown trout and abundantly inhabited. The riverbed structure is evenly composed of fine gravel and gravel, which constitutes the conditions necessary for habitat and spawning. However, the spawning grounds, spawned eggs and hatched fry have not yet been clearly identified, so continuous research is needed.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2011년도 학술발표회
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• pp.185-185
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• 2011

Mapping of artificial levee lines, one of major tasks in river zone mapping, is critical to prevention of river flood, protection of environments and eco systems in river zones. Thus, mapping of artificial levee lines is essential for management and development of river zones. Coastal mapping including river zone mapping has been historically carried out using surveying technologies. Photogrammetry, one of the surveying technologies, is recently used technology for national river zone mapping in Korea. Airborne laser scanning has been used in most advanced countries for coastal mapping due to its ability to penetrate shallow water and its high vertical accuracy. Due to these advantages, use of LiDAR data in coastal mapping is efficient for monitoring and predicting significant topographic change in river zones. This paper introduces a method for construction of a 3D artificial levee line using a set of LiDAR points that uses normal vectors. Multiple steps are involved in this method. First, a 2.5-dimensional Delaunay triangle mesh is generated based on three nearest-neighbor points in the LiDAR data. Second, a median filtering is applied to minimize noise. Third, edge selection algorithms are applied to extract break edges from a Delaunay triangle mesh using two normal vectors. In this research, two methods for edge selection algorithms using hypothesis testing are used to extract break edges. Fourth, intersection edges which are extracted using both methods at the same range are selected as the intersection edge group. Fifth, among intersection edge group, some linear feature edges which are not suitable to compose a levee line are removed as much as possible considering vertical distance, slope and connectivity of an edge. Sixth, with all line segments which are suitable to constitute a levee line, one river levee line segment is connected to another river levee line segment with the end points of both river levee line segments located nearest horizontally and vertically to each other. After linkage of all the river levee line segments, the initial river levee line is generated. Since the initial river levee line consists of the LiDAR points, the pattern of the initial river levee line is being zigzag along the river levee. Thus, for the last step, a algorithm for smoothing the initial river levee line is applied to fit the initial river levee line into the reference line, and the final 3D river levee line is constructed. After the algorithm is completed, the proposed algorithm is applied to construct the 3D river levee line in Zng-San levee nearby Ham-Ahn Bo in Nak-Dong river. Statistical results show that the constructed river levee line generated using a proposed method has high accuracy in comparison to the ground truth. This paper shows that use of LiDAR data for construction of the 3D river levee line for river zone mapping is useful and efficient; and, as a result, it can be replaced with ground surveying method for construction of the 3D river levee line.

• Development and Reproduction
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• 제24권1호
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• pp.63-70
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• 2020

This study aimed to investigate early life of Coreoperca herzi living in Han River and compare morphological differences between different groups during the development in order to provide basic data for relevant taxonomic research. On average, one female individual spawned 541 to 861 eggs (average 701) at once. After 259 hours, the tail broke out of the egg membrane and hatching began. Immediately after hatching, the larvae were average 7.81±0.10 mm (n=5) in total length. 60 days the juvenile was average 35.9±1.30 mm (n=5) in total length. The white spots spread to the rest of the body, rending the same pattern as that on the body of their broodstock fish.

• Journal of Korea Water Resources Association
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• 제42권5호
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• pp.407-414
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• 2009

A quantitative analysis was conducted to study the impacts of artificial flow alteration on fish habitate condition change in the Geum River downstream the Daechung Multi-purpose Dam (DMD). River Analysis Package (RAP) was employed for the analysis and three fish species of black shiner, long nose barbel and Korean shinner were selected as icon species. The results of the analysis showed enhaced fish habitat conditions during low flow seasons in spring and fall after DMD construction, while the impact of the Youngdam Multipurpose Dam located upstream the DMD was insignificant. This result could be attributed to the fact that the increased flow during dry seasons helped create preferable habitat conditions for the fish species tested in this study.

• Korean Journal of Ecology and Environment
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• 제56권1호
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• pp.1-13
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• 2023

Targeting Microcystin (MC), which is most abundantly detected in the North-Han River water area, we analyzed the relationship between the MC biosynthesis gene (mcyA gene), cyanobacteria cell density, and MC concentration, derived an RNA-MC conversion formula, and derived the cyanobacteria. The concentration of MC present in cells was predicted. In the North-Han River waters, the mcyA gene was found mainly at downstream sites of the North-Han River after Muk-Hyeon Stream junction, and higher copy numbers were found on average than other sites. In the Uiam Lake waters upstream of the North-Han River, the mcyA gene copy number increased at the Kong-Ji Stream point, and after September, the mcyA gene copy number decreased throughout the North-Han River waters. The expression of the mcyA gene was concentrated in the short period of summer due to the spatio-temporal difference between upstream and downstream water bodies. The mcyA gene expression level was not only highly correlated with MC concentration, but also correlated with the cell density of Microcystis aeruginosa and Dolichospermum circinale, which are known to biosynthesize MC. Six conversion formulas derived based on the RNA-MC relationship showed statistical significance (p<0.05) and exhibited high correlation coefficients (r) of 0.9 or higher. The expression level of MC biosynthesis gene present in eRNA determines the synthesis of cyanotoxin substances in water, quickly quantifies gene activity, and can be fully utilized for early warning of MC development.

• Korean Journal of Ecology and Environment
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• 제50권2호
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• pp.195-206
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• 2017

We described a spatial distribution pattern and floral diversity on the Paspalum distichum community occurring at the ecological parks of Hwamyeong, Daejeo, Samnak, and Maekdo in the Nakdong river estuary. A total distribution area of P. distichum community was $303,462.6m^2$. Its largest area was found in Samnak eco-park ($185,910.1m^2$). The most richness of knotgrass patches in each ecological park was determined Maekdo eco-park (87). Cover class level-5 shows the largest area ($260,663.2m^2$). A total of 73 taxa (34 families, 55 genus, 65 species, and 8 varieties) were listed up on the P. distichum community. A welldeveloped population of knotgrass was found predominantly at sites linked into human impacts at the riverine floodplain, the stream courses flowing through the parks, and the man-made channels and wetlands. Finally we proposed an ecological management strategy for knotgrass population in the study area.