• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.475-491
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• 2016

The Changwon and Nam streams that run through the Changwon city were evaluated based on longitudinal and horizontal configurations and vegetation state in order to prepare a restoration plan. Riparian vegetation of the Changwon and Nam streams are normally dominated by herbaceous plants. However, the woody plants, Salix pseudolasiogyne, Rubus parvifolius, Salix koreensis, Robinia pseudoacacia, and Amorpha fruticosa have appeared. Planting to introduce various types of plants for landscape architecture has also been observed. Evaluation of naturalness based on the vegetation state of both Changwon and Nam streams showed very low naturalness of degree 1 or 2, with the exception of a few reaches of the upstream sector. In these few reaches of the upstream sector, Salix koreensis and Salix chaenomeloides showed heights at the subtree level, however, they were located at the position of shrubland close to the waterway. These reaches were, therefore, evaluated as degree 3 rather than degree 4 in naturalness. The result of diagnostic evaluation classified by reach indicated the requirement for active restoration, such as transformation of the channelized stream into a meandering one and a step-type cross section into a pool-type one, introduction of vegetation suitable to the region and site, and creation of an ecological network between the stream and the surrounding terrestrial ecosystems.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.311-321
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• 2018

The purpose of this study is to investigate effect of stream channel naturalness on ecological health by using environmental factors and Fish Assessment Index (FAI) in the Han River of South Korea. These samples and data have been released from the research project titled Stream/River Ecosystem Survey and Health Assessment, which was conducted in 444 sites in the Han river watershed from 2008 to 2016. All samples were classified into five groups according to a degree of morphological changes of stream. Water chemistry analyses indicated a decline in water quality by decreasing stream channel naturalness, it is assumed that channelized stream was vulnerable to aquatic pollution compared to the natural meandering stream. In the result of frequency of dominant species, sensitive species and insectivore such as Zacco koreanus, Rhynchocypris kumgangensis and Pungtungia herzi were frequently dominated in the natural meandering stream while tolerant species and omnivores such as Carassius auratus and Cyprinus carpio were more dominated in the channelized streams. The FAI in the channelized stream shows decline to average of $46{\pm}25$ compared with that of the natural meandering stream ($80{\pm}20$). The decrease in FAI was highly influenced by changes in matrixes of fish assemblage structure such as number of sensitive species (M3), portion of omnivores (M5) and insectivores (M6). Moreover, annual average FAIs from 2008 to 2016 were significantly correlated with water chemistry, especially TN, TP and BOD ($r^2=0.59$, p<0.0001). Taken together, all the results suggest that the stream channelization could negatively impact on the water quality and fish assemblage structure, leading to degradation in aquatic ecosystem health.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.85-95
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• 2015

Recent years, nationwide projects for ecological restoration are implemented with emerging issues on the stream ecosystem. In order to enhance effectiveness of the ecosystem restoration and reduce negative impact, the appraisal of effectiveness through the follow-up monitoring and the adaptive management process are executed in consecutive phase. In this study, planning phase, monitoring and adaptive management in Hakui stream which is part of An Yang stream restoration project is introduced as representative ongoing case of effective adaptive management. The aim of this study is to verify the adaptive management process and suggest direction of effective restoration. Restoration project of Hakui stream resulted in increasing number and diversity of species (vegetation, fish, bird, invertbrates, amphibian and reptilia) according to monitoring from 2004 to 2013, and enhancing natural river landscape by evaluation of river naturalness among 2001(before restoration), 2007 (after), 2015 (recent). However, excessive vegetation expansion or sediment deposition on channel over time caused unexpected results such as terrestrialization or degradation of habitats. Adaptive management action such as removing disturbance species (Humulus japonicus)(2007), coppicing willow (2007), release of march snail (2007), creation of wetland (2014) were implemented based on monitoring results. And then appraisal of management action was discussed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.2
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• pp.73-92
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• 2019

The purpose of this study is to establish the conservation and restoration areas for sustainable stream management by reflecting the ecological health, cultural characteristics, and the citizens' needs for stream uses. Therefore, we extended spatial ranges of stream evaluation to riparian areas in addition to stream sections. The evaluation indexes are stream naturalness, availability, biota assessment, and riparian characteristics such as land uses and legally protected areas. The grading system was unified with five classes. The spatial evaluation units for stream section are classified as right and left for laterally and 500m for longitudinally. For riparian areas, 30m and 100m of distance from the edge of stream are applied as spatial evaluation units. The six types of stream sections for management are conservation sections(priority/general) and restoration sections(priority/general) for ecological landscape and core and general sections for cultural landscape. The established system for evaluation and designating areas for stream management was applied to Jeonjucheon and Samcheon in Jeonju-si, and the conservation and restoration areas were designated reflecting the characteristics of urban and non-urban areas and left and right of stream sections. The results of this study will provide detailed guidelines for designating stream sections and practical management strategies for sustainable urban stream management.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.384-401
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• 2016

The vegetation assessment indicator has been developed recently as a biological part of the integrated assessment system for river environment to improve the efficiency of river restoration projects. This study carried out to test the vegetation assessment indicator and to reset its grade criteria on experimental streams. We classified and mapped vegetation communities at the level of physiognomic-floristic composition by each assessment unit. A total of 204 sampling quadrats were set up on the 68 assessment units at 5 experimental streams. By analyzing the vegetation data collected, we examined the appropriate numbers of sampling quadrats, the criteria of vegetation index score, classification of vegetation community, and grade criteria for vegetation assessment. The developed vegetation assessment indicator composed with the vegetation complexity index (VCI), the vegetation diversity index (VDI), and the vegetation naturalness index (VNI) was proved to reflect the current conditions of the streams sufficiently. The contribution of vegetation naturalness index to grading by vegetation assessment indicator was larger, but three indexes were closely correlated to each other. Also there was more clearer discrimination of grading with the application of adjusted criteria of vegetation assessment indicator and the standardized classification of vegetation community, but the stream segment type did not influence the vegetation assessment grade significantly.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.45-64
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• 2014

This study was carried out to offer the ecological data for restoring and maintaining a local stream by analyzing the vegetation and flora in Geumsan Stream and Gisa Stream, Geumsan-gun, Chungcheongnam-do, Korea. As a result of comparison of realities of land use near Geumsan Stream and Gisa Stream, in Geumsan Stream, the ratio of residential areas, commercial and business places, and places of transportation facilities was high. With these types of land use aggregating densely in the center, farmlands were formed on both sides. On the other hand, in Gisa Stream, farmlands were distributed evenly in all sections. As a result of comparison of flora of the two streams, Geumsan Stream had a total of 166 taxons including 53 families, 131 genuses, 139 species, 23 varieties, and 4 forms, and Gisa Stream had a total of 142 taxons including 42 families, 111 genuses, 116 species, 21 varieties, and 5 forms. As a result of calculation of the Naturalization Index and Urbanization Index, the indices were analyzed to be 23.5% and 12.1% in Geumsan Stream and to be 21.8% and 9.7% in Gisa Stream, respectively. Hence, Geumsan Stream showed higher figures in both evaluation indices than those of Gisa Stream. In addition, as a result of calculation of the Actual Urbanization Index, which is the index supplemented by considering the species pool and area, it could be known that Geumsan Stream (0.0285) was urbanized more than Gisa Stream (0.0107) by about 2.7 times. A total of 18 plant communities were classified in Geumsan Stream and Gisa Stream. In Geumsan Stream, 14 vegetation types were identified, and it was analyzed that there are various vegetation types including Phalaris arundinacea community, Zoysia japonica community, Phragmites japonica-Phalaris arundinacea community, etc. evenly distributed. 11 vegetation types were identified in Gisa Stream, and it was examined that Phragmites japonica community is widely distributed in all sections.

• Journal of Environmental Policy
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• v.11 no.3
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• pp.67-96
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• 2012

The Ministry of Environment in Korea has been promoting the urban stream restoration project for paved streams in cities as the restored Cheonggyecheon. As an elementary study for suggesting policy implications for the project, cost and benefit criteria for an ex-post analysis on the Cheonggyecheon project is suggested in this study. The ex-ante analysis were reviewed critically by focusing on the cost and benefit criteria. Ex-post analysis plan in this study is developed considering the standard guideline of pre-feasibility, the theory of cost-benefit analysis, and the review results. The costs for compensating lands, amending conflicts, researching rivers, and maintaining water quantity were also included. For the benefits, this study proposes to estimate the benefits with the assessment on naturalness of stream. The results are expected to contribute to increase the efficiency of the urban stream restoration project and evaluate the project to match better with the meaning of the river restoration.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.317-328
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• 2013

The aim of this study is to compare the effects of the maintenance water supply methods on the ecological restoration of 5 urban streams such as Mugeo cheon, Yaksa cheon, Yeocheon cheon, Myeongjeong cheon and Cheokgwa cheon in Ulsan metropolitan city. Water quality of the streams have been innovatively improved and the ecosystems have gradually been restored by supplying maintenance water constantly. However, we found that if the maintenance water was in a state of higher salinity or low quality, even enough supply was not helpful and even harmful for ecological restoration. We confirmed that the most important things to create or maintain from the urban stream to the ecological stream are that facilities like a walkway construction should be installed at least, supplying appropriate maintenance water, and a connection with the main stream.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.647-657
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• 2018

This study was carried out to review as criteria for zoning at management plan for river restoration, in case of naturalness of river environment and suitability of water friendly activity suggested at assessment system of river environment in Korea. As a result of reviewing law and guidelines concerned, historic & cultural resources used as criteria for preservation zone, it was judged that the historical and cultural value as the preservation zone needs to be examined in connection with waterfriendly activity zone. In this study, we propose a sequential evaluation method to distinguish the waterfriendly activity zone by applying suitability of waterfriendly activity reflecting land use social characteristics, followed division of preservation and restoration zone at the first stage by the naturalness of river environment reflecting the natural environmental characteristics as a result of application to the test bed, Gap and Yudeung streams. In particular, it was concluded that the results of the present study provided more clear criteria for the problem that the last criteria for zoning did not reflect the difference between the left and the right side of stream, or the designation of the excessive water friendly zone. On the other hand, the criteria for designation in this study reflect the characteristics of various river environments as well as the setting of assessment unit based on the physical characteristics of rivers, and other legal regulations and local situations should be adjusted and supplemented in administrative procedures.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.189-203
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• 2013

The purpose of this study is to build a GIS database that can utilized to provide a multi-dimensional analysis of aquatic health ecosystem. Especially, it was to build a GIS database for comprehensive analysis using the aquatic ecosystem health. So we collected data on aquatic ecosystem health assessment, Korea Reach File(KRF), Stream Naturalness and Water Environmental Information System, and detailed analysis of the collected data was performed. In addition, the core objects were extracted from individual data and a related entity was derived by pulling out the items associated with thematic characteristics and classifying them. The establishment of GIS database makes it possible to support the decision making for the user to quickly understand the information of water environment. Therefore, the database will provide the information for the effective management on water environment.