• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.1
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• pp.20-33
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• 2006

Changing of industry structure and development of traffic and telecommunications requires a change of the knowledge about the space where the human beings reside. Step by step the world is being divided into specified utility blocks. Today there is a limit that only one local government can compete with another region in the world. This study provides decision support tools with the use of GIS on the regional level for regions competition. GIS establishes regions and analyzes their geographic environment data, which will help in local-government problem solving and provide framework data for similar regions to become the community. The wide-area GIS application can present an objective and rational basis for regulation of inefficient investments and excessive competition between adjacent regions. The study area is Gangwon-do. Considering specific features of Gangwon-do which preserved high-quality environment resources, river basins were taken as a basis among natural regional elements. The main object of analysis conducted were the facts relevant to environmental regulation. The Gangwon-do consists of three regions in this study: Yongdong region, North-Hangang region and South-Hangang region. The analysis of each region regulation cases showed the following: in Youngdong region the forests regulation rate is high, in North-Hangang region the military installations protection sector's rate as well as regulation rate for water resources protection is relatively high, in South-Hangang region the forest and water resources regulation rate is high. The percentage of forests and water regulation rate appeared to be rather high in Gangwon-do, which means that the value of forest and water resources there is very high.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.55-66
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• 2007

This study was conducted to analyze the distribution patterns of wintering waterbird communities in relation to local environmental factors in the urban streams of Seoul, Korea. A field survey was conducted at 66 sites of 5 tributaries and the main channel of the Hangang River in Seoul in January 2006. The total of 65 species and 39,560 individuals were recorded in the field survey. There were 48 species and 28,989 individuals in the Hangang River, 14 species and 1,395 individuals in the Tancheon stream, 15 species and 2,306 individuals in the Jungrangcheon stream, 22 species and 5,990 individuals in the Anyangcheon, 18 species and 283 individuals in the Changrungcheon stream, and 24 species and 597 individuals in Gokrungcheon stream. The dominant species were Anas platyrhynchos (22.65%), A. poecilorhyncha (14.01%), Aythya ferina (13.26%), Aythya fuligula (8.04%), and Mergus merganser (7.03%). Among the 16 species (with 30,650 individuals) of ducks, the dabbling and diving ducks were 8 species with 18,286 individuals and 8 species with 12,364 individuals, respectively. Through the principal component analysis, the study sites were classified into four main groups according to the similarity of their waterbirds' species compositions: 3 tributaries in the urban area (Group 1), 2 tributaries in the rural area (Group 2), one in the rural area, one in the urban area, the urban area in Hangang River (Group 3) and the main channel of the Hangang River in the urban area (Group 4). Species diversity index and species evenness were the highest in Group 1, while the lowest Group 2. Analysis on their environmental factors showed that the waterbirds wintering in urban streams of Seoul prefer broad water width, low water depth and broad resting sites.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.101-111
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• 2008

Hangang Parks have been played an important role as the source of various Civilian activities by providing a natural space near Han River ever since it was developed. Due to the local-heavy rain caused by recent climate change, the Hangang Parks tends to be easily overflowed. Evacuation of the park in emergency and its controlled system should be made for the sake of Civilian's safety. In this study, various basic data and several parameters were analyzed to simulate the hydraulic effect of Hangang Parks based on the outflow in $P1/4{\div}1/4^3$ Dam. Rising effects of flood water level were investigated through the one-dimensional and twodimensional numerical hydraulic models. Relationships of water level and travel time of flood between key station and centeral part of each park were also identified. It can be used to forecast the future flood water level of each individual park in Hangang Parks. Obtained results can be used to establish the rational plan of usage, management, citizen's safety, and emergency action plan of the Hangang Parks as the flood is occurred from the outflow of Paldang dam.

• Journal of Wetlands Research
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• v.23 no.2
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• pp.154-162
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• 2021

The naturally opened Han river estuary is a place where the flows of the Han river, Imjin river, Yaesung river meet with West Sea of Korea, so the hydrodynamic mechanism(Impact-Response) structure of Han river estuary is complex. Continuous observation and measurement due to the morphological characteristics at the estuary are required to maintain the estuary environment and river management facilities. However, the Sannam wetland(the study area) is in the military operation area. Therefore, Sannam wetland has the limited access under the control from military office. In 2020, there had a natural disaster due to flooding in August and COVID-19, and it made a survey hard. The noncontact survey technique, the analysis of LANDSAT images at Sannam wetland, was applied to analyze riverbed fluctuation and morphological transformation around Sannam wetland. LANDSAT images obtained from EarthExplorer, USGS and analyzed by QGIS. The analysis was performed based on the area and the distance near Sannam wetland. As a result, an erosion was happened on the downstream of the study area, and the upstream of the study area did not have any serious sediment transport. Considering the resolution of LANDSAT images, this noncontect survey technique is applicable to manage the study area. From the analysis of LANDSAT images, it is assumed that the tidal effect is greater than the inflow from the upstream. The pattern change of tidal response causes the damage of the river facilities near the Hangang river estuary.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.344-354
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• 2020

Identification of the target species of 2-MIB (2-methyllisoborneol) production is crucial in the management of off-flavor problem in the freshwater system. This study was conducted to identify 2-MIB-producing Pseudanabaena strains occurring in the North Han River system using molecular genetic method. Eleven phenotypes of Pseudanabaena were isolated from several mainstream sites of the North Han River, including Sambong-ri, Joam-myun, and Lake Uiam areas. Despite of morphological similarity of the strains, the phylogenetic analysis using 16S rDNA classified them into different species with low genetic similarity (40~55%). Isolated Pseudanabaena strains were converged to four species; Pseudanabaena cinerea, P. yagii, P. mucicola, and P. redekei. Among them, the 2-MIB synthesizing gene (mibC) was detected in P. cinerea, P. yagii, and P. redekei. However, actual 2-MIB production was detected only in P. cinerea and P. redekei based on gas chromatography analysis. This study is the first report of the molecular identification of Pseudanabaena strains and their 2-MIB production potential in Korea. The results of this study provides an evidence of species diversity of Pseudanabaena occurring in the North Han River.

• Korean Journal of Ichthyology
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• v.30 no.3
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• pp.144-154
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• 2018

This study investigated the characteristics of fish communities at the Hangang River in Seoul from Jun 2016 to March 2017. During the survey period, there were 56 species of 17 families collected from 5 survey stations. The species that appeared mainly in the brackish water was Coilia nasus, Leiocassis nitidus, Lateolabrax maculata, Repomucenus olidus, Trachidermus fasciatus, Mugil cephalus, Chelon haematocheilus, Synechogobius hastus, Tridentiger bifasciatus and Takifugu obscurus. The migration fish of Anguilla japonica, C. nasus, Plecoglossus altivelis, Hypomesus nipponensis and T. obscurus appeared in this surveyed area. Korean endemic species were 11 species (17.9%) and accounted for a low rate. There were 6 species (10.7%) exotic species including Cyprinus carpio, Carassius cuvieri, Hypophthalmichthys molitrix, Megalobrama amblycephala, Lepomis macrochirus and Micropterus salmoides. The dominant species by stations were Acheilognathus gracilis (St. 1) and Hemibarbus labeo (St. 2, 3, 4, 5). Regarding the tolerance guild according to water quality, there were 3 (7.1%) sensitive species, 24 (42.9%) intermediate species, and 28 (50.0%) tolerance species. Twenty (35.7%) were insectivore species, 18 (32.1%) were omnivore species, 14 (25.0%) were carnivore species, and 4 (7.1%) were herbivore species, indicating the dominating presence of insectivore and omnivore fish species.

• Journal of Korean Society on Water Environment
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• v.27 no.2
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• pp.200-209
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• 2011

The purpose of the study is to optimally manage sewage treatment plant with analysis of phosphorus contribution and improvement of water quality contributing rate in the effect of inflowing point of effluent and Pal-Dang lake after reducing T-P discharge from large scale public sewage treatment plant at upstream of Pal-Dang lake. Also, this study, for enforcement of T-P in effluent, plans optimal management of effluent T-P through examining propriety of environmental, technological, and economical aspect such as water quality standard of domestic and foreign T-P and related policy. In regarding optimal management of T-P discharged from public sewage treatment plant located in upstream of Pal-Dang lake, the study drew following conclusions. With the optimal management of public sewage treatment plant, it showed that a pollution level became higher in the order of Sumgang E in South-Han river, C in Dalcheon, B1 B2, A in North-Han river, and J in Kyungancheon, and it is required reduction of T-P first. The highest value in analysis of benefit-costs from sewage treatment plant in the selected research area was Kyungan B, and the others are with the order of Jojong A, Bokha A, Kyungan A, and Yanghwa A. With result of this study, all 14 areas are required more enforced phosphorus treatment. The study resulted that the most top priority areas were Hangang F, Sumgang B, and Gyungan A, top priority areas were Bokha A, Dalcheon B, and Cheongmi A, priority areas were Hangang E, Heukcheon A, Gyungan B, and Jojong A, and potential areas were Sumgang A, Yanghwa A, Dalcheon A, and Hangang D. It seems to be appropriate to apply 0.2 mg/L of T-P treatment for water supply source reservation, 0.5 mg/L for the other areas by locally, and 0.2~0.5 mg/L for biological nitrogen phosphorus treatment method and 0.5~1 mg/L for Conventional Activated Sludge by technologically. Also, it may be appropriate to apply 0.2 mg/L for the most top priority area(I), 0.3 mg/L for the top priority area(II), 0.4 mg/L for priority area(III), and 0.5 mg/L for potential area(IV) by the separation of priority area.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.403-408
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• 2017

This study aims to set up the basic data to manage the waterfowl habitat through the analysis of the changes of physical structure according to the time series of Hangang(Riv.) as water birds' habitat. Study area was 41.5km in length from Paldang bridge to Hangju bridge. during total length of 497.52km and horizontal boundary was based on the protected lowland in year 1975. As the analysis result of land use from the center of water to adjacent road to the river, ratio of year 1975 was in order of sedimentary land(22.7%), surface water(20.7%), built-up area(16.9%), field(16.2%), paddy field(15.9%), and afterwards most of the areas were changed through the construction of arterial highway and submerged weir in order to use Hangang(Riv.). In year 1985, the area ratio of protected lowland(57.8%) and surface water(32.8%) dramatically increased. After construction of river bank the recreational areas continually increased and relatively natural areas decreased. In year 2005, the area ratio of protected lowland was enlarged to 57.6% and surface water also to 33.3%. While the length of both riversides and naturalness decreased by 10.9%, 91.5% respectively in year 2005 compared to year 1975, the depth of water increased by 1.46m. Comprehensively, the flow of changes by physical structure in Hangang(Riv.) for 30 years was divided into two periods. The main characteristics in the first period were decrease of riverside area and enlargement of the surface water through the massive construction before middle of year 1980, and afterwards revetments were intensively artificialized with changes of land use for amusement area. In terms of water fowl habitat, Hangang(Riv.) which previously had various types of habitat condition was changed into simplified habitat for few of species, and the active improvement apporach was needed for habitat diversity.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.250-256
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• 2005

A benthic faunal survey of the Hangang Estuary located in the northwestern part of South Korea was performed in October 2004. A total of 11 species identified, which were comprised of two species of molluscs bivalves (Limnoperna fortunei and Corbicula felnouilliana) in two families, two species of annelids polychaetes (Neanthes japonica and Nephtys caeca) in two families, and seven species of decapods (Palaemon carinicauda, P. annandalei, P. modestus, Ilyoplax deschampsi, Eriocheir sinensis, Eriocheir leptognathus and Sesarma dehaani) in four families. Four of the 11 species in six families, Limnoperna fortunei, Neanthes japonica, Nephtys caeca and Palaemon modestus, were newly found in this study area. Eleven species were presently listed with brief ecological remarks.

• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.182-190
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• 2020

The endangered Pseudopungtungia tenuicorpa were reintroduced to the Jojongcheon Stream in the Hangang River 2011~2012 as part of the restoration project. Since then, the restoration project has been evaluated as a failure because the P. tenuicorpa were not collected from the discharge site 2014~2016. This study was conducted 2017~2019 to verify that the P. tenuicorpa restoration project failed. Six locations were selected, including the discharge site, and the fish collection method used skimming nets, cast nets, long bag set nets, and scuba diving. In the survey results, 13 individuals were collected in a 0.5 km section, including the discharge station. The P. tenuicorpa habitat was approximately at a water depth of 0.5 m to 2 m in run water flow with the boulders and rocks. The age of the collected P. tenuicorpa were 0+ to 3-years-old, and the generation alternation was occurring stably. Thus, the P. tenuicorpa restoration project was evaluated as partially-successful, as the P. tenuicorpa, re-introduced to the Jojongcheon Stream, settled in its habitat with stable generation alternation.