• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.2
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• pp.86-101
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• 2004

This study was conducted to present the ecological management of Goduk Riverside Restoration Area in Hangang, Seoul by analyzing the change of the vegetation structure. The survey site was classified into three groups. These were the vegetation restoration area, the dry plant area, and the swampy plant area. There were 141 taxa including naturalized plants and 13 species recorded in 2001 and 258 taxa including naturalized plants and 42 species were recorded in 2003 by monitoring. Monitoring results showed that the alien plants such as Humulus japonicus expanded continuously except in the vegetation restoration area. It was found that the growing status of planted shrub plants were poor, and the naturalized plants status was thriving, and the soil environment was bad in the vegetation restoration area. The alien plants such as Humulus japonicus and Aster pilosus dominated continuously in the dry plant area. The swampy native herb plants number was decreased, but the Humulus japonicus community was expanded caused by the soil drying in the swampy plant area. Soil analysis showed that the soil acidity, the available phosphates and the concentration of calcium were highly effected by cultivation. We propose ecological management as follows based on the results of the change of vegetation and soil characteristics. The vegetation restoration area should be managed by visitor's characteristics. Replanting vegetations should be based on soil characteristics. The removal of naturalized plants and established monitoring with plots is also needed. In the dry plant area and the swampy plant area, naturalized plants need to be removed in order to facilitate bio-diversity and monitoring.

• Journal of Korean Society on Water Environment
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• v.37 no.5
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• pp.369-380
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• 2021

In this work, we analyzed the effects of drought on the water temperature (WT) of Nakdong river basin major river sections using Standardized Precipitation Index (SPI) and WT data. The analysis was carried out on a seasonal basis. After calculating the optimal time scale of the SPI through the correlation between the SPI and WT data, we used the copula theory to model the joint probability distribution between the WT and SPI on the optimal time scale. During spring and fall, the possibility of environmental drought caused by high WT increased in most of the river sections. Notably, in summer, the possibility of environmental drought caused by high WT increased in all river sections. On the other hand, in winter, the possibility of environmental drought caused by low WT increased in most river sections. From the risk map, which quantified the sensitivity of WT to the risk of environmental drought, the river sections Nakbon C, Namgang E, and Nakbon K showed increased stress in the water ecosystem due to high WT when drought occurred in summer. When drought occurred in winter, an increased water ecosystem stress caused by falling WT was observed in the river sections Gilan A, Yongjeon A, Nakbon F, Hwanggang B, Nakbon I, Nakbon J, Nakbon K, Nakbon L, and Nakbon M. The methodology developed in this study will be used in the future to quantify the effects of drought on water quality as well as WT.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.3
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• pp.33-47
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• 2021

This study was conducted to investigate the influence of eco-friendly restoration in forested bog on the structure of benthic macroinvertebrate community. The benthic macroinvertebrates collected from the surveyed sites were composed of 1,071 individuals, 60 species, 40 families, 13 orders, 6 classes and 5 phyla. At the control and Site 3(small dam), the number of species and individuals were larger than that of other sites, and EPT group ratio was same as well. Considered by index, the dominance index (DI) was found the highest at the biotope area. The diversity index (H') and richness index (RI) were the highest at the control and Site 3. In addition, the ecological score of benthic macroinvertebrate (ESB) showed the highest at site 3, while the lowest at biotope area. The stability and recovery of benthic macrointebrates showed different according to restoration types at forested bog. After restoration project, the benthic macroinvertebrates were observed to get recovery at Site 3, and to have the highest communities stability at control and Site 3. At biotope areas (Site 4, Site 5 and Site 6) communities stability were the lowest, but showed different community stability values according to the presence of water. It is confirmed that the eco-friendly restoration projects indeed provided the better environment for the inhabitation of benthic macroinvertebrate community. The change of community index depending on the restoration projects suggests that the eco-friendly restoration can provide a more suitable environment for benthic macroinvertebrate ecosystem that prefers the stream environment.

• Journal of The Geomorphological Association of Korea
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• v.28 no.2
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• pp.1-13
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• 2021

It is very important to secure sufficient river maintenance flow for the ecosystem, since the ecosystem in the downstream section of the dam is greatly affected by the stream maintenance flow from the dam. However, the amount of discharge from the Seomjingang Dam is decreasing year by year, this study estimated the ecological flow required for the downstream section of the Seomjingang Dam, which is known as the habitat of the endangered Acheilognathus somjinensis, in order to secure the river flow of the Seomjingang Dam. For this purpose, the proper discharge was calculated using the PHABSIM model, which is a hydrological survey and physical habitat simulation method, and the proper discharge of other fish species were also comprehensively reviewed. As a result of this study, the current river maintenance flow at the Seomjingang Dam partially satisfies the ecological maintenance flow including the Acheilognathus somjinensis in the downstream section of the Seomjingang Dam. However, this is recognized as the minimum discharge to maintain the ecology in the downstream section of the Seomjingang Dam, and it would be more desirable to secure larger river maintenance flow than this. This study can contribute the determination of the river maintenance flow of the Seomjingang Dam by proposing the river maintenance flow considering the fish habitat environment in the river.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.314-325
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• 2014

We studied fish fauna at 10 study sites in Ungcheon stream for 4 times from April to October, 2011 to investigate the influence of artificial structures such as dam (with fish-way) and weir (without fish-way), and abandoned mine on fish community. A total of 12 families, 36 species of fishes were collected. Dominant species was Zacco platypus (23.4%) and subdominant species was Zacco koreanus (20.5%). Ten species (27.8%) of Korean endemic species and Micropterus salmoides, exotic species, were observed during the study period. Endangered species of Korea such as Pseudopungtungia nigra and Liobagrus obesus, and Korean endemic species, Coreoperca herzi, which are vulnurable for water quality and had been observed in previous study, were not identified in this study. According to the cluster analysis, Ungcheon stream were divided into three groups consisting upstream (St.1, St.2, St.3), midstream (St.4, St.5, St.6, St.7), downstream (St.8, St.9, St.10). Community structure similarity between upper and lower site of Boryeong dam with fish-way (St.6-St.7) was high, whereas that of weir, lack of fish-way (St.7-St.8) showed little similarity indicating that fish-way was required. According to the canonical correlation analysis, high level of conductivity and salinity at upstream was detected and Misgurnus mizolepis, and endemic species of Korea such as Silurus microdorsalis, Coreoleuciscus splendidus and Iksookimia koreensis were observed at this part of the stream. Since Korean endemic species, Squalidus gracilis majimae cohabit with exotic species, M. Salmoides at downstream whose width is wide and water velocity is low, protection was needed for these endemic species.

• Journal of Environmental Impact Assessment
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• v.23 no.2
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• pp.75-87
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• 2014

In order to analyze environmental impact of livestock manure and organic fertilizers, this study investigated livestock-breeding and pollution loads, the status of individual and public livestock manure treatment facilities, and the status of production, supply and components of compost and liquid fertilizers in the Nonsan area. Also, on a trial basis, this study investigated the life cycle of the environmental impact of livestock manure and its organic fertilizers on stream, groundwater, and agricultural soil. The results are as follows. Firstly, were detected the range of $0.13{\sim}1.32{\mu}g/L$ of As, $0.004{\sim}0.467{\mu}g/L$ of Cd and $0.5{\sim}9.2{\mu}g/L$ of Pb as a harmful substances which show lower concentrations than person preservation criteria of water qualities and aquatic ecosystem. However, it is not clear that heavy metals affect environment such as stream, groundwater and agricultural soil. Secondly, this influence could change according to investigation time and treatment efficiency. As were detected large amounts of persistent organic pollutants(e.g. $14.24{\sim}38.47{\mu}g/L$ of acetylsalicylic acid, $1.17{\sim}2.96{\mu}g/L$ of sulfamethazine, and $2.25{\sim}174.09{\mu}g/L$ of sulfathiazole) in effluent from livestock farms and small amounts of sulfathiazole($ND{\sim}1.63{\mu}g/L$) in the stream, it is necessary to monitor POPs at individual and public livestock manure treatment facilities. However, significant environmental impact did not appear at groundwater and agricultural soil in the test area supplied with liquid fertilizers. These results could be applied to investigate the environmental impact of livestock manure through a comprehensive livestock manure management information system.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.535-545
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• 2011

This study was carried out to suggest the baseline data necessary for vegetation restoration by naturalness assessment of riverine wetland within stream corridor. We selected stream reach both of near nature and urbanized by Nonsan stream and Hongchun river as experimental site. Composition of vegetation community and land use pattern between two sites indicated considerable difference, which imply for many different watershed property and process disturbed each other at river ecosystem. Naturalness of the sampled reaches showed that near nature is in better condition for riverine wetland than urbanized of all two sites. However, the prevalence index of Hongchun river within its natural state was lower than that of Nonsan stream, because the index included some vegetation communities occurred at upland fringe and bank slope. In conclusion assessment system using prevalence index would be considered an effective method for evaluating of natural states of riverine wetland.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.462-468
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• 2004

Most of the surveys of periphyton carried out for environmental and ecosystem health assessment of streams have considered the impact made on their fixative substrates (stones, rocks, sand, silt, clay and other abiotic matters), but there has been virtually no research that considered moving substrates. This study attempted to make an analysis and assessment of the habitat environments of the microalgae attached to the skin surfaces of fish living in small streams, with a focus on their species composition and community structure. The dominant fish in the this survey were Zacco temmincki and Zacco platypus, which are usually found in the streams, and rivers, and they accounted for 62% and 19%, respectively, in relative abundance. Substrates of fish, a representative organism with the trait of moving a long distance, show a marked contrast with those of organisms fixed at a certain place. Characteristics of both the upstream and the downstream reach well reflected in the microalgae attached to the skin surface of fishes, of which diatoms took the major composition. The result of this observation is considered to be useful to provide basic data in assessment of stream health. Also it may be suggested as a biological tool for the assessment of aquatic environment in the future.

• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.74-82
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• 2003

This study was carried out to understand how the bird community would change in a stream ecosystem after implementation of close-to-nature river improvement techniques conducted on the Gwacheon, Seocho and Hakyeul reaches in the Yangiae Stream, 'Seoul. At the Gwacheon reach, the number of species and individuals tended to decline. However, at the Seocho reach, the number of species was increased while the number of individuals appeared to be not changed greatly. Especially, density of Dabbling Ducks were rapidly increased. At the Hakyeul reach was both the number of species and the number of individuals were increased. Density of Herons and Dabbling Ducks rose, while density of Wagtails was decreased suddenly. Except the Gwacheon reach, the survey areas were gradually improved in species richness and density after the construction of river improvement. We suggested that the naturally-formed meandering (channel) bar, restoration of riparian vegetation and artificial ponds were helpful for birds habitation, however bicycle path constructed in flood plain was negative.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.371-378
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• 2014

The subject of this study is the Gongchon-cheon which is one of the largest streams in Incheon and is closely related to lives of citizen. Comparative analysis is made on the changes of the environment and the ecological condition of Gongchon-cheon after the stream naturalization construction which is completed in July 2009. From the results of the survey, 32 species in 2004, 22 species in 2009 and 46 species in 2010 have been recorded. The number of the species decreased from 2004 to 2009 due to the disturbance of the river environment, and it increased in a short time from 2009 to 2010 because of the recovery of the environment. It demonstrates the stream naturalization construction providing enough environments (dikes and rapids) for the benthic macro invertebrates. The result of the present study is similar with the river's biology index, ESB index, and KSI index, and also it is similar with the pattern of the appearance, which illustrates that the species decreased during the naturalization construction, and increased after the stabilization since the finish of the naturalization construction, and it has been confirmed that the naturalization construction provides the better environment for the inhabitation of organisms.