• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.2
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• pp.35-46
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• 2000

Environmental pollution has become more and more serious in urban areas since industrialization as most streams and rivers were developed heavily because of economic opportunism. Recently river restoration techniques, applied in advanced countries, have been introduced to Korea. But the application of river restoration techniques developed in advanced countries, has a lot of limitations in respect of economic loss during construction, suitability for the domestic situation and the problem of flood control. The method of minimizing the problems must take into consideration these issues, including economic considerations. So from these points of view this study intends to plan ecological river restoration and to create a nature friendly river in the case of the Chungrang river. The subject site is the upper part of Chungrang river, from the Nokchun bridge to Sang-kye bridge, where the ecosystem is well preserved in comparison with other parts of the river. The subject site is divided into 10 sections for plant state investigation. The result of plant-state investigation showed pioneer water plants such as Persicaria thunbergii, Oenanthe jaranica, Rumex crispus. appeared very often. On the basis of the existing plant state, this study has planned an appropriate plant state for the river and has planned for bank protection using a method of construction, which is suitable for natural river. In this study, first of all, it is intended to investigate the plant growth state of Chungrang river and try to plan a particular ecosystem for the river for the purpose of the revival of the natural river.

• Ecology and Resilient Infrastructure
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• v.1 no.2
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• pp.82-93
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• 2014

In recent years, "ecological river restoration" taking into account the flood control, water utilization and environmental aspects of rivers is actively being investigated. However, it is hard to understand the inhabitation conditions of living organisms that live on the river with distinct characteristics have been fully reflected, and with the use of limited methods, it ends in uniformed composition of artificial rivers and a mere customary stream channel maintenance, resulting in frequently disturbed stream channel habitats As a fundamental study for investigating the habitats of living organisms that live on rivers, this study intends to examine each habitat type by dividing domestic rivers into sand rivers and gravel rivers depending on the nature of rivers and dividing sections of each river into central river sections and natural river sections. As a result, more diverse habitat types of organisms were found in the gravel rivers rather than in the sand rivers, and the habitat types of organisms in the central river sections where the river restoration project have been already conducted reached approximately 56.3 % of those that appeared in the natural river sections.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1405-1411
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• 2012

This study deals with the case of "Close-to-Nature Improvement Work of Cheonancheon and Wonseongcheon in Cheonan", which has been completed at the end of 2009. The purpose of this study is to evaluate the result of this work and suggest a future direction of development and supplementation of this project. In the course of his study, theoretical researches about urban stream and restoration precedents, observational survey and user questionnaire and comparative analysis have been conducted. According to the study, the most prominent problems of Cheonancheon in comparison with Wonsungcheon are water pollution, low use and participation of residents. As location based future development concept, Cheonancheon as various event space for visitors, Wonsungcheon as recreational space for residents are suggested.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.431-451
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• 1996

The present studwas undertaken to classify and describe the riverside vegetation around Hanchon (36°27’-36°51’N, 128°15’-128°37’E), a tributary in the upper stream area of Nak-tong River, South Korea by methods of the ZM school of phytosociology. As a result the vegetation was divided into twenty three associations and communities belonging to ten classes. Reflecting various human impacts in the past, the associations and communities of the Artemisietea principis were most plentiful there. The vegetation units obtained in the present study were as follows: A. forest vegetation A-1 Fagetea crenatae:Zelkova serrata community, Larix leptolepis community; B. Shrub vegetation B-1 Salicetea sachalinensis:Salicetum gracilistylae, Salicetum graciliglandis assoc. nov., B-2 Rosetea sachalinensis:Salicetum gracilistylae, Salicetum graciliglandis assoc. nov., B-2 Rosetea multiflorae:Stephanandra incisa community, Lycium chinense community; C. Grassland vegetation C-1 Lemnetea minoris:Spirodela polyrhiza-Lemna paucicostata community, C-2 Bidentetea tripartiti:Polygonetum thunbergii, Polygonetum sieboldii-hydropiperis, Panico Polygonetum hydropiperis, Pharagmitetea :Oenantho- Phalaridetum arundinaceae, Phragmitetum japonicae, Miscanthetum sacchariflori, Phragmites australis community, C-4 Artemisietea principis:Artemisia princeps community, Impatiens textori community, Lactuco indicae-Humuletum japonicae, Pueraria lobata-Humulus japonicus community, Pennisetum alopecuroides community, C-5 chenopodietea:Echinochloa crus-galli var. orizicola community, Digitaria adsecendens community, Polygonum nodosum community, C-6 Miscanthetea sinensis: Miscanthus sinensis community, C-7 Plantaginetea:Eragrotis multicaulis-Plantago asiatica community. It is inferred that the endemic vegetation units in the riverside vegetation of Korea are very rare, because most of the vegetation units obtained in the present study are common with those of Japan. Among the above vegetation units, the Salicetum graciliglandis was established as a new association. On the other hand, the associations and communities of classes characterizing the riverside vegetation increased with a decrease of human impacts from the downstream to the upstream in Hanchon, while the number of the naturalized plants was the reverse. Also based on the present phytosociological work, the relation between the vegetation units and their environmental conditions and the restoration ecology and nature conservation of the riverside vegetation were discussed here in detail.

• KCID journal
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• v.21 no.1
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• pp.118-126
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• 2014

In this study, the use of the spur of riverbank technique is being investigated. The spur of the riverbank typically reduces the velocity of flow and protects the embankments by increasing friction along the water and the banks. This also has an effect in the rise of water level upstream. It is also used for the rectification of riverside line and restoration of the waterway through sedimentation near the spur of the riverbank. In this study, physical-scaled experiments are conducted to investigate the process of creating a mild meandering channel using the spur of the riverbank with varying water flows and sedimentation functions. The hydraulics observations are taken with respect to the varying heights and length of the riverbank's spurs and the distance between each spur for the formation of the mild meandering channel. It is observed that for 1.06 times of the meander length, it requires 2 times of the interval with each spur of river width. Similarly, 1.25L times of the meander length, it requires 0.5 times of the interval with each spur of river width. The sand accumulation is induced by the spur of riverbank when the spur of riverbank's heights are more than 40% of water depth and the length of the spur of riverbank needs under than 20% of river width for avoid exaggerated sand accumulation in the center of channel.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.325-330
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• 2011

In order to revive the ecological function of degraded rivers, a total restoration plan for riverbeds and riparians needs to be developed. Previous evaluations for rivers were mainly focused on the river's physical structures. Therefore, this research has developed indicators to evaluate a riparian restoration considering biodiversity. Through literature and previous cases review, 4 fields and 13 indicators are selected for the evaluation. Four fields are biodiversity, habitat diversity, connectivity and habitat functionality. In the biodiversity field, 4 indicators of the exuberant extent of herbaceous vegetation and their diversity, the exuberant extent of shrub and woody plants and their diversity, the number of plant communities and naturalized plants are included. Habitat diversity are comprised of 4 indicators of the longitudinal continuity of vegetation, the mixture of plant communities, the extent of plant type color fruit abundance and the distribution of vegetation. Connectivity includes 3 indicators of target distribution, the shore slope of low water channels and the extent of artificial embankment materials. Habitat functionality has 2 indicators of the status of food supply plants and the habitat functionality. The value weighting for the fields and indicators has been calculated based on the AHP(Analytic Hierarchy Process) method. 50 experts were surveyed with quantifiable questionnaire, among them 43 experts have more than 10 yesrs experiences in the nature restoration field. The selected and weighted indicators have been tested to the 12 sections in Gap stream located in Daejeon. In conclusion, the indicators are feasible and the selected indicators could be used to establish the direction and objectives of riparian restoration.

• Journal of Environmental Science International
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• v.16 no.7
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• pp.831-838
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• 2007

In order to improve the water environment at urban streams in Korea, several river restoration projects have been initiated for past few years. This study evaluates the impact of diverting water application at the riverhead of Onchun stream through the monitoring program for several water quality and ecological parameters. Various water quality parameters and ecological item such as benthic macroinverterates has been investigated between 09/05 and 12/06. Analysis indicates that the application of diverting water from Nakdong river to Onchun stream distinctly improved several water quality parameters such as, PH, BOD, TN, TP and concentrations of heavy metals. Low flow augmentation also improve ecological indicies such as the diversity index of benthic macroinvertebrates. Generally speaking, releasing addition water from head water of Onchun stream improves various water environmental characteristics.

• 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.

• Korean Journal of Environment and Ecology
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• v.21 no.5
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• pp.390-399
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• 2007

We analyzed the vegetation environment at the stream section of habitat in which Cottus koreanus lives. The plant communities were classified into Fraxinus rhynchophylla community, Acer ginnala-Salix koreensis community, Phragmites japonica-Salix gracilistyla community, Salix gracilistyla community, Phragmites japonica community, Robinia pseudo-acacia community, and Oenanthe javanica-Persicaria thunbergii community. The frequency of Phragmites japonica-Salix gracilistyla community was the most. And also the frequencies of Fraxinus rhynchophylla community and Salix gracilistyla community were high. In stream bank zone and terrace zone, the typically represented vegetation was the Fraxinus rhynchophylla community and Acer ginnala-Salix koreensis community and Phragmites japonica-Salix gracilistyla community, respectively. The rNCD of the top-priority plants applied to restoration of the vegetation in stream bank zone came out by the order of Ulmus davidiana var. japonica, Salix koreensis, Acer ginnala, Salix gracilistyla, and Fraxinus rhynchophylla. The rNCD in terrace zone was arranged by the order of Salix gracilistyla, Phragmites japonica, and Artemisia princeps. The spatial distribution of vegetation was the most greatly influenced by cross-sectional position of the surveyed stream, and this aspect is believed to be due to the habitat's physical stability. Species diversity also obviously makes a great difference depending on their surrounding physical stability.

• Journal of Korea Water Resources Association
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• v.40 no.12
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• pp.1007-1014
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• 2007

Recently, existing river improvement methods for flood control purpose have changed into nature friendly river improvement methods and the efforts to improve the river environment including river restoration have been made, and close-to-nature river improvement and nature friendly river restoration are actively conducted all over the country. In the present situation where various revetment methods are used after the introduction of the concept of close-to-nature river improvement, the environmental characteristics of rivers need to be considered to apply more suitable revetment methods. Therefore, as a precedent study for the development of revetment evaluation techniques and methods for close-to-nature river improvement, the present study suggested evaluation techniques using detailed survey items through field survey. Evaluation items of hydraulic stability consist of mode of streamline, stream bed gradient, flow velocity and tractive force ratio and those of environmental efficiency consist of revetment of vegetation, state of river water, land use of the terrace land on the river, vegetation and materials of the terrace land on the river. Each item was graded with the point 1 through 5. Hydraulic stability and environmental efficiency was evaluated by the points which were averaged in each items. As the result of the application of the proposed evaluation technique, it was found that a number of existing revetments excessively focus on hydraulic stability with little consideration about environmental term. It is expected that the proposed technique in the present study can be used as a base for providing guidelines to construct the design and construction of revetments in the future.