• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.615-624
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• 2004

The distribution pattern of water quality parameters and phytoplankton biomass in upper inflow rivers of lake Paldang had surveyed. In North-Han river system, nutrient concentrations and algal biomass was below the standard of mesoand oligotrophy from lake Soyang to lake Paldang, maintaining good water quality, except the N5 site located near the Chuncheon-Si, showing high nutrients concentrations and algal biomass. The algal biomass of the South-Han river system showed oligotrophic level in the upstream near the lake Chungju, and increased along the flow direction showing eutrophic level in the downstream within the lake Paldang area. On the other hand, the highest concentrations of nutrients were detected in the middle stream near the Yeoju-Si and Yangpyung-Gun rather than in the downstream suggesting algal biomass in lake Paldang would not come from the upper river area but come from the growth within the lake area using nutrients from the upper inflow river.

• The Korean Journal of Malacology
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• v.1 no.1
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• pp.1-4
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• 1985

The investigation of freshwater molluscs in the South Han River was carried out from 1984 and in 1985. The authors selected 12 stations and collected freshwater snails and mussels. We here publish the catalogue of molluscs in South and North Han River. The catalogue of molluscs in the South Han River is as follows; two classes, four orders, six families including twenty species(Semisulcospira coreana, Semisulcospira globus, Semisulcospira gottschei, Semisulcospira forticosta, Parafossarulus manchouricus, Gabbia misella, Radix auricularia coreana, Austroppepleaollura, Limnoperma lucustris, Lamprotula gottschei, Lanceolariaacrorhyncha, Unio douglasiae, Unio sp, Solenaia triangulalis, Anodonta fukudai, Anodonta woodiana, Corbicula felnouilliana, Corbiculafluminea, Corbicula sp).

• Journal of Industrial Technology
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• v.18
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• pp.399-404
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• 1998

The purposes of this research were constructed the database, based on graphing the present water pollution in Han-river due to livestock wastewater(LSW). The LSW was below 1% in respect to quantity but about 7% in respect to pollutants loading in overall Han-river. The ratio of untreated LSW is 18% to 28%, which was higher compared to the municipal and industrial wastewater. In other words, LSW was about 0.05 times of municipal wastewater in respects to quantity but 2 times in respect to the ratio of untreated wastewater. So, it was necessary for treating LSW. The pollutants loading due to livestock wastewater of the South Han-river, North Han-river and main stream were 19.7%, 19.4% and 4.0%, respectively. This was about 7% in overall Han-river. We separated the Han-river into upper, mid and down stream. As a result, we found that the livestock wastewater is the main water pollution source of upper Han-river.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.263-271
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• 2015

To evaluate the relationship between dynamics of cyanobacteria and odorous compounds, a monthly monitoring of water quality and phytoplankton were conducted at the three serial lakes (Lake Ui-am, Lake Cheong-pyeong and Lake Pal-dang) in the North Han River for 11 times from May 2014 to March 2015. In the three serial lakes, phytoplankton communities showed that seasonal changes in Bacillariophyceae-Cyanophyceae-Bacillariophyceae. Anabaena and Pseudanabaena were dominant species in August and September 2014. At the same time the odors (Geosmin, 2-MIB) were also detected with high concentration. Relationship between environmental factors and cyanobacterial abundance showed a significant correlation with Anabaena circinalis and geosmin (r=0.983, p<0.01). In the case of Pseudanabaena limnetica showed a significant correlation of total nitrogen (r=0.685, p<0.01) and NO3-N (r=0.723, p<0.01). In addition, similarly Pseudanabaena limnetica and 2-MIB (r=0.717, p<0.01) was high. The odorous compounds appeared in the North Han River water were considered to be a direct relationship with cyanobacteria.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.6
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• pp.152-161
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• 2006

This study is the primary study for analyzing the classifying characteristics of river wetlands in Korea and China. It is the first step for constructing the wetlands inventories and establishing the wetland conservation strategies in North-Eastern Asia. The case study sites are Han-river which is the representative river of Korea and Tu-men river which is flowing on the borderline of 3 nations, China, North Korea and Russia. The results are as follows : 1. The types of wetlands of Han-river in Korea and Tumen-river in China were classified by the methods of Koo(2002) which is focused on the topography and hydrology and Zhu(2002) which is emphasized the vegetation and habitats. 2. There are three features which are hydrology, topography and soil cover, and vegetation to classify the wetlands into each types. 3. According to the two wetland types by Koo and Zhu, classification system, wetlands in the case study area(Han river and Duman river) were classified by types. 4. In Koo's classifying system(2002), lots of Riverine, Lacustrins and Flat wetlands are found because the topographical and hydrological features are emphasized. On the contrary in Zhu's system(2002), there are lots of Palustrine wetlands because of emphasizing the vegetation. 5. By the topographic and geological characteristics of each sites, there are more wetland types in the lower Tumen river.

• KCID journal
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• v.9 no.2
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• pp.68-77
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• 2002

Return flow rate of agricultural irrigation for rice culture was investigated in the North Han river basin, Two small paddy watersheds were chosen and irrigation, drainage, infiltration and evapotranspiration were monitored and estimated during the irriga

• KCID journal
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• v.7 no.2
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• pp.57-65
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• 2000

The effect of land use of an alluvial watershed in the upper North Han river basin on groundwater quality were investigated. Existing 20 farm wells were selected as monitoring wells representing different land uses of residential, arable(paddy and field),

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.1
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• pp.187-196
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• 1988

Meander characteristics of the Han River System using autocorrelation coefficient and variance spectrum were analysed, and meander paths were simulated by direction and direction-change series in this paper. Better wavelength estimates are obtained from direction-change spectra, dominant wavelength had the increasing tendency in order tributaries of the North Han River System, the South Han River System and the Han River Downstream System. The meander characteristics of tributaries in the North Han River, the South Han River and the Han River Downstream System could be obtained from the results of direction and direction change spectra. Direction and direction-change autocorrelograms are generally of damped oscillatory form, and wavelengths estimated from direction-change autocorrelograms correlate closely with wavelength estimated from direction-change specta.

• Journal of Korea Water Resources Association
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• v.34 no.2
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• pp.119-130
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• 2001

At-site and regional frequency analyses of annual maximum 1-, 2-, and 3-days rainfall in Han River basin was performed and compared based on the regional L-moments algorithm. To perform regional frequency analysis, Han River basin was subdivided into 3 sub-basins such as South Han River, North Han River, and downstream regions. For each sub-basin, the discordancy and homogeneity tests were performed. As the results of goodness of fit tests, lognormal model was selected as an appropriate probability distribution for both South Han River and downstream regions and gamma-3 model for North han River region. From Monte carlo simulation, RBIAS and RRMSE of the estimated quantiles from regional frequency analysis and at-site frequency analysis were calculated and compared each other. Regional frequency analysis shows less RRMSE of the estimated quantiles than at-sites frequency analysis in overall return periods. The differences of BRMSE between two approaches increase as the return period increases. As a result, it is shown that regional frequency analysis performs better than at-site analysis for annual maximum rainfall data in Han River basin.

• 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.