• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.9-18
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• 2008

The fundamental objects of the Korean Grand Canal (KGC) Project are the rehabilitation(or restoration) of river corridor ecology, improvement of river water quality, reduction of flood damages, countermeasure of the huge rise in energy price and the high discharge of $CO_2$ due to the vast use of energy for highway logistics. The other important objects, like an increase of water in the river channel, are to provide people with the pleasure of seeing the water and intimacy (touchiness) with it, an increase of flood controllability, effects of dilution of river pollutants, dredging out sedimentary pollutant from the river bottom, the function of infrastructure to pare down the logistics (distribution) costs, and the opportunity to expand tourism. These kinds of fundamental concepts must be evaluated as future values in Korea and elsewhere.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.196-196
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• 2011

본 연구에서는 일본 다마천 자갈사주의 식생 이입 과정을 조사하고, 과도한 식생 이입에 영향을 미치는 하상토의 특성과 수리적 특성을 분석하여 자갈사주의 복원을 위한 방안에 관하여 조사하였다. 다마천 자갈사주는 넓게 분포하였던 자갈하천(white river)에 버드나무 등의 식생이 과다하게 성장하여(green river), 이를 억제하기 위한 대책을 수립하여 시행하였다. 또한 이곳에 서식하는 고유종(야생 국화)를 복원하기 위한 연구도 진행되었다. 다마천 자갈사주 식생번무의 원인으로, 자갈과 모래 채취, 하천 개수, 상류의 댐과 보의 축조를 들 수 있으며, 자갈사주를 복원하기 위한 종합적인 연구계획이 수립되어 사업이 시행되었다. 복원 대책으로 홍수터를 파고 모래톱 복원, 상류로부터 자갈과 모래 공급, 저수로 확장, 과다 성장한 버드나무나 아카시아 벌목, 표토 제거를 계획하였으며 이를 시행하였다. 모래톱은 성긴 조약돌로 포설하였으며, 다양한 높이로 조성하여 침수 빈도를 다양하게 변화시켰다. 가장 높은 모래톱은 5년 빈도로 하였다. 자갈사주의 복원 및 관리를 위한 모니터링 그룹도 발족하여 현재 자갈사주의 복원 모니터링이 진행 중이며, 이를 바탕으로 체계적이고 계획적인 복원 사업이 진행되고 있다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4B
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• pp.213-220
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• 2012

Old river channels have been formed by engineering a straight channel in Korea. This can be classified as wetland-type or land-type. The wetland-type old river channel uses parts of agricultural water supply. However, the channels have been neglected since there are problems associated with poor water quality, reduced water level, ecosystem disturbance, etc. Thus, river maintenance through preservation and restoration of old river channel can be very effective in watershed management. To achieve this, functional assessment of wetland-type old river channel is a priority need. This study applied the wetland-type channel in Mangyoung river for functional assessment. It was formed these channels with regard to the following four major criteria (Natureless, Habitat, Water-friendliness and Water quality) and 21 indices. The indices managed by measuring depending in weights. Consequently, wetland-type channel in Mangyoung river was in good condition both natureless and habitat, while it was a fragile environment in water-friendliness and water quality. In particular, the areas where it has insufficiency water and water suffering from eutrophication needs urgent improvement. This results will be used to utilize wetland-type old river channel as watershed management.

• 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.

• Korean Journal of Ichthyology
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• v.36 no.2
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• pp.139-155
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• 2024

Using the cytb gene region of the mitochondrial DNA of eight populations of Sarcocheilichthys nigripinnis morii and five populations of S. variegatus wakiyae, which belong to the genus Sarcocheilichthys from Korea, the genetic diversity and molecular phylogenetic relationships of each population were examined. As a result of the analysis, it was confirmed that the S. variegatus wakiyae population had higher genetic diversity than the S. nigripinnis morii population. In the phylogenetic tree of genus Sarcocheilichthys fish in Korea based on the cytb gene, the Yeongsan River (YSR) population of S. variegatus wakiyae forms a clade with the Tamjin River (TJR), Yeongsan River (YSR), and Seomjin River (SJR) population of S. nigripinnis morii, and genetic relationships that do not align with the current classification system were observed. Meanwhile, on the nuclear DNA phylogenetic tree, S. variegatus wakiyae and S. nigripinnis morii could be clearly distinguished, showing mitonuclear inconsistency where mitochondrial and nuclear DNA conflicted on the phylogenetic tree. The Seomjin River (SJR) population of S. nigripinnis morii was translocated to the Dongjin River (DJR) population, haplotype from which crossbreeding was presumed to have occurred was confirmed. Among the rivers flowing into the East Sea, the S. nigripinnis morii population is known to have been introduced and inhabit only the Hyeongsan River (HSR), and it is presumed to be a population formed by translocation from the Han River (HR) population, with a haplotype representing a unique genetic group also confirmed. The Han River (HR), Geum River (GR), and Mangyeong River (MGR) populations of S. nigripinnis morii formed a genetically identical population with S. czerskii and S. soldatovi distributed north of the Yalu River, and accordingly, a taxonomic reexamination was required through morphological and molecular phylogenetic studies by securing various specimens.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.822-829
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• 2011

The purpose of the present study is to estimate the ecological instream flow for conservation and restoration of fish habitat in running water ecosystem which has very important status for stream environment. Estimation of the ecological instream flow in the present study was carried out by application of a two-dimensional depth averaged model of river hydrodynamics, River2D model. It can model fish habitat in natural streams and rivers and assess the quality of physical habitat accoriding to the species preferences for habitat suitability. Zacco platypus and Zacco temmincki were selected as target fish species in the study area of the Seomjin river. The Habitat Suitability Criteria (HSC) developed by Sung et al. (2005) were used for target fish species, life stages and habitat conditions in the study. Weighted usable area (WUA) was computed by the River2D model considering preferences of target fish species for velocity, depth, and channel substrate. The result revealed that the ecological instream flow of $10.0m^3/s$ is needed to maintain the target fish habitat at each life stage in the river.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1523-1536
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• 2014

Restoration is the process of reducing or reversing damage to an ecosystem so that it can function in its original manner. However, many restoration programs do not achieve this. In the Nakdong Estuary, the largest migratory nesting site in the center of the East Asian-Australasian flyway, an estuarine barrage was constructed in the 1980s that required site restoration following its completion in 1987 and the expansion of several large industrial complexes(Noksan and Jangrim) and a residential development(Myeongji). The goal of the restoration was to restore the function of the wetland to its pre-disturbance state. To achieve this, a restoration program was designed consisting of three stages. The first stage(1993-1995), saw the construction of three artificial wetlands(Shinhori, Daemadeung, and Eulsuk), the second(2003-2005) involved the dredging and returning of farmed lands to their natural state, and the third(2008-2012) focused on the rehabilitation and vegetation development of the wetlands. However, the project has not achieved all of the desired goals, and it is an example of the lapses in ecological restoration following anthropogenic disturbance. Issues that resulted in an incomplete restoration included the timing of the stages, noncompliance with the restoration plan, not directly monitoring the restoration or continuing the monitoring following completion of the development project, and the political subversion of the restoration plan. For the success of the restoration plan, it is necessary to avoid mistakes such as inconsistent monitoring, unequal levels of stakeholder involvement, and political interference.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.2
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• pp.70-77
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• 1999

This study was carried out to suggest an effective method for the rehabilitation of Close-to-Nature River and artificial wetland. The results on the revegetation methods by seeding and sodding of Phragmites japonica, Miscanthus sacchariflorus, Themeda triandra, and Pennisetum alopecuroides were summarized as follows. Seed germination of Phragmites japonica was 76.3% at $30^{\circ}C$, that of Miscanthus sacchariflorus was 68.7% at $20^{\circ}C$, that of Themeda triandra germinated 52.3% at $25^{\circ}C$, $30^{\circ}C$ constant temperature and that of Pennisetum alopecuroides germinated 86.7% at $30^{\circ}C/20^{\circ}C$ alternating temperature. Seed germination of Pennisetum alopecuroides exceeded 80% at $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$ constant temperature and $25^{\circ}C/15^{\circ}C$ alternating temperature. At 60 days after seeding, the ground coverage of Phragmites japonica, Miscanthus sacchariflorus, Themeda triandra, and Pennisetum alopecuroides reached 81%, 81 %, 74%, and 86% respectively in the soil media of vermiculite and peatmoss(1 : 1 by volume). In the results of sod experiment, Phragmites japonica, Miscanthus sacchariflorus, Themeda triandra, and Pennisetum alopecuroides were formed sod completely in soil composition type of vermiculite and peatmoss(1 : 1, v/v). Thus this media seems to be best sad production media for rehabilitation works of Close-to-Nature River and man-made wetlands. Phragmites japonica and Miscanthus sacchariflorus were not significantly different in shoot height and the number of tillers by different planting distance for the first one year of experiment. Pennisetum alopecuroides shows high possibility to be used for Close-to-Nature River rehabilitation works by seeding.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1239-1243
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• 2005

The water quality of the Ian Stream, a tributary of the Na14dong River, was estimated to provide an information in establishment of an ecological restoration plan for fan dam which will be constructed in near future. Seven stations were selected in upstream (3 stations) and downstream (4 stations) of Ian Stream, centering the construction site of Ian dam. Samples were collected at the surface water of 7 stations selected on May 1, June 16, and September 1 in 2004. The values of DO, pH, and BOD are satisfied Grade I for river water standard in nearly all sites. The concentrations of total nitrogen (TN) and total Phosphorus (TP) showed low level with ranges of $1.10\~2.25\;mgN/L,\;5\~14\;{\mu}gP/L$. However, the total and fecal conform bacteria were detected in nearly stations, especially high at the upstream stations. The number of fecal conform bacteria corresponds to the Grade III for river water standard. In addition, some metals (iron, manganese) were detected during dry season. As a consequence, general water quality of Ian Stream satisfied Grade I for river standard and it is expected that pollution loads from watershed is not significant. However, the detection of fecal conform, which is thought to be from livestock and residents, and some metals originating mimes watershed can have a potential health risk exists for aquatic organisms lived in Ian Stream. It needs to be solved by the construction of wastewater treatment plant to diminish the health risk from stream water polluted by fecal conform and metals, and to provide the safe ecological habitat for aquatic organisms.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.147-154
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• 2011

Physical habitat assessment models based on Instream Flow Incremental Methodology have been developed as a decision making tool to estimate appropriate discharge for environmental flow and water use management. These models, however, require extensive knowledge on various academic disciplines, complicated input data, and empirical data. We propose a Simplified Habitat (SIMHAB) simulation model for the estimation of physical structure of fish habitat and environmental flow at the planning stage. SIMHAB is applied to a river system for which physical and ecological data are available, and its applicability is investigated. Simulated results appeared to be similar to field survey data and those of such models as PHABSIM and River2D. However, SIMHAB requires much less input data. As such, the proposed model, SIMHAB can easily be applicable to river restoration projects including designing of physical habitat, estimation of environmental flow, and water resource management.