• Journal of architectural history
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• v.28 no.6
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• pp.55-65
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• 2019

Ganggyeong, a city which is located at riverside of Geum River, played a role to connect the inland cities and the coastal cities through the Geum river waterway. In Chosun dynasty, Ganggyeong was one of the three major markets in Korea, and at the same time, it was one of the two river docks in Korea. However, after the railway was installed in Korea, railroad was more important than waterway in transporting logistics and in 1911 Honam railroad and Ganggyeong railway station was installed. Thus it was necessary to reorganize urban structure of Ganggyeong city from the traditional river-dock city to modern railroad city. In addition, urban infrastructure to prevent flood damage was needed because Ganggyeong suffered from floods and water shortages every year. Therefore, between 1910s and 1930s large-scale social infrastructures including road, water and sewage system, river bank, floodgate was constructed not only to revitalize the declining city but also to prevent flood damage and water shortages that hinder urban development. The installation of urban infrastructure has enabled the urban expansion and development of Ganggyeong city, and it is still served as a basic urban structure.

• Magazine of the Korean Society of Agricultural Engineers
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• v.20 no.3
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• pp.4739-4749
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• 1978

This studies were conducted to derive synthetic unitgraphs and triangular unitgraphs correlated with watershed characteristics which can be used to the estimation and control of flood for the rational development of Agricultural water resources. Derived Synthetic unitgraphs and Triangular unitgraphs can be applied to the ungaged watersheds were compared with average unitgraphs by observed data. Seven small watersheds were selected as studying basins Han, Geum, Nakdong, Yeongsan and Inchon river system. The results summarized for these studies are as follows: 1. Average unitgraphs by observed data and dimensionless unitgraphs for synthesis were derived for all river systems. 2. Peak discharge per unit area of the unitgraph, qp, was derived as qp=10-0.389-0.0424Lg with a high significance. 3. Formulas for the base width of unitgraph of 50 and 75 percent for peak flow for each water systems was adopted as Table 5. 4. The base length of the unitgraph, Tb, in hours in connection with time to peak, Tp, in hours was expressed as Tb =4.3Tp. 5. Peak discharge, Qp, were obtained as Table 6 by the Triangular form to all subwatersheds. 6. Relative errors in the peak discharge of the synthetic unitgraphs showed to be 7.3 percent to the peak of observed average unitgraphs except errors of peak discharge for Yeongsan river system. This indicates that Synthetic unitgraphs for the small watersheds of Han, Geum, Nakdong and Inchon river systems can be applied to the ungaged watersheds. On the other hand, It was confirmed that the accuracy of Instantaneous Unit Hydrograph with only 1.6 percent as relative errors was approaching more closely to the observed average unitgraph than that of synthetic unitgraph with relative errors. 23.9 percent for Yeongsan river system. 7. Errors in the peak discharge of the triangular unitgraph to the observed average unitgraph showed to be 0.6 percent to 7.5 percent which can be regarded as a high precision within the range of 200 to 500$\textrm{km}^2$ in area. On the contrary, application of triangular unitgraph within the range of 200$\textrm{km}^2$ in area has defined as a unsuitable method because of high relative errors, 26.4 percent to 61.6 percent.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.329-338
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• 2006

Phylogenetic relationships and DNA polymorphism among local populations of the Korean native catfish species, Liobagrus mediadiposalis, have been investigated based on mitochondrial cytochrome b DNA sequences. As a result, three genetically distinct groups of local populations were recognized based on the phylogenetic tree constructed. The first group was called "Nakdong-river group" that included the local populations from Geumho-river, Gyeongho-river, and Deokcheon-river; the second one was "Geum-river group"; the third one was represented as "Seomjin-river group" that included the samples from Seomjin-river, Dongjin-river and Geokum-do. The phylogeny also implied that the ancestral group of L. mediadiposalis have first evolved to Nakdong-river group, and later two local populations (Geum-river and Seomjinriver group) were diverged from the other lineage. DNA polymorphisms we observed were 4.4~4.7% between Geum-river group and Seomjin-river group, 5.1~5.5% between Seomjinriver group and Nakdong-river group, and 5.5~5.7% between Nakdong-river group and Geumriver group. These results indicated the long period of geographic isolation due to the river system in Korea caused such high degrees of DNA polymorphisms between local populations of L. mediadiposalis.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.60-70
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• 2018

The distribution of benthic macroinvertebrates was investigated at 1,157 sites of 7 main water systems in Korea, including 442 sites of Han River system (Namhan River, Bukhan River, Han River main stream, Anseongcheon, etc.), 305 sites of Nakdong River system (Nakdong River, Hyeongsan River, Taehwa River, etc.), 199 sites of Geum River system (Geum River, Sapgyocheon, Mangyeong River, Dongjin River, etc.) 102 sites of Seomjin River system (Seomjin River), 102 sites of Yeongsan River system (Yeongsan River, Tamjin River, etc.), and 7 sites of Jeju stream system. A total of 151 families were found in the whole survey sites, including 141 families in Han River, 122 in Nakdong River, 115 in Geum River, 106 in Seomjin River, 113 in Yeongsan River, and 50 in Jeju. Chironomidae (20.8%) was the most dominant species in Korea, followed by Hydropsychidae (17.1%), Baetidae (12.6%), Tubificidae (10.3%), Heptageniidae (8.6%), Ephemerellidae (6.3%), Asellidae (2.7%), Leptophlebiidae (2.4%), Planariidae (1.7%), and Tipulidae (1.6%). Substrates compositions consisted of large sand (22.6%), large gravel (18.4%), silt (10.5%), and boulder (8.2%). The mean stream width was 133.5 m and the mean watercourse width was 61.7 m. The mean water depth and velocity were 30.2 cm and $33.1cm\;s^{-1}$, respectively. Results of cluster analysis based on distributional characteristics of benthic macroinvertebrates were divided into six groups according to the frequency of benthic macroinvertebrate taxa which appeared in the study area. Finally, altitude, current velocity and substrate composition were the most influencial factors determining the distribution patterns of macroinvertebrate communities.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.283-291
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• 2014

To study the distribution characteristics of diatom communities in relation to the gradient of water quality and land-use, water samples and epilithic diatoms were collected from 90 sites including mainstream and tributaries, in the Geum River System (GRS) during no rainfall, May 2011. Of 239 taxa identified, Achnanthes convergens and Cymbella minuta were dominated over all the sites. Cluster analysis on the GRS divided into three groups. Group 1 (G1) is the mountainous upstream, a relatively good water quality, and mainly consisted of saproxenous species. Group 2 (G2) is the urban sites, polluted (high in electric conductivity, total phosphate and soluble reactive phosphorus), and saproxenous and common species. Group 3 (G3) is the agriculture sites, and polluted (turbidity, total nitrogen, nitrate), and saprophilous species. There were some discrepancies between abiotic and biotic variables in GRS; biologically similar between G1 and G2, but abiotically similar between G2 and G3. These differences may attribute to not only physiological characteristics of diatom cells, but complicate relationships between microhabitat and water quality. Thus, an urgent development of generalized or standardized methods to diminish the differences between epilithic diatom community and environments is advent.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.319-328
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• 2014

Dorang - the Korean term for headwater streams - occupy a large portion of the total stream length in a basin, and contribute significantly towards the quantitative and qualitative characteristics, and the ecosystem, of the main river. The Ministry of Environment of South Korea has supported the investigation of the status of Dorang in the nation's four major basins, since 2007. Without a widely accepted academic or legal definition of Dorang, however, there are limits to understand the distribution of Dorang at the national scale and to systematically compile a Dorang database. This paper, through a review of the stream classification system and Korean legal system delineating streams, defines Dorang as 1st and 2nd order streams according to the Strahler ordering method, in a 1:25,000 geographical scale. Analysis of the Geum River basin, with this definition, reveals that the total length of Dorang is 20,622.4 km (73.6% of total stream length), and the number of Dorang catchments is 23,639 (71.3% of the basin area). Further analysis of the geomorphological characteristics of Dorang catchments shows that the average total stream length is 1.1 km, average catchment length is 1.2 km, average drainage area is $0.4km^2$, and average drainage density is 3.08/km.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2322-2324
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• 2002

Korea Water Resources Corporation (KOWACO) operates nine hydroelectric power stations on the Han River, Nakdong River, Geum River & Seomjin River Areas. KOWACO will take the lead in improving the efficiency of water resources supply in this parer, KOWACO Generation Intergrated Operating System(GIOS) project will improve the generating plant, hydraulic structures, switchgear, and station controls, alarms and services for unmanned remote controlled operation by modern intergraed SCADA system. Mordern SCADA is used to cover all computer systems designed to perform the following main functions: - to collect data from industrial plant devices. - to process and perform calculations on the collected. - to present collected and derived data on displays on. - to accept commands entered by human operators and act on them such as sending control commands to plant devices.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.81-90
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• 2007

Watershed topographical information is required in hydrologic analysis, supporting efficient hydrologic model operation and managing water resources. Watershed topographical data extraction systems based on desktop GIS are abundant these days placing burdens for spatial data processing on users. This paper describes development of a Web-based Geographic Information Systems that can delineate the Geum River sub-basins and extract watershed topographical data in real time. Through this system, users can obtain a watershed boundary by selecting outlet location and then extracting topographical data including watershed area, boundary length, average altitude, slope distribution about the elevation range with Web browsers. Moreover, the system provides watershed hydrological data including land use, soil types, soil drainage conditions, and NRCS(Natural Resources Conservation Service) curve number for hydrologic model operation through grid overlay technique. The system operability was evaluated with the hydrological data of WAMIS(Water Management Information System) with the government operation Web site as reference data.

• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.148-158
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• 2014

In order to assess the effect of TMDLs management and improve that in the future, it is necessary to analyze long-term changes in water quality during management period. Therefore, long term trend analysis of BOD was performed on thirty monitoring stations in Geum River TMDL unit watersheds. Nonparametric trend analysis method was used for analysis as the water quality data are generally not in normal distribution. The monthly median values of BOD during 2004~2010 were analyzed by Seasonal Mann-Kendall test and LOWESS(LOcally WEighted Scatter plot Smoother). And the effect of Total Maximum Daily Loads(TMDLs) management on water quality changes at each unit watershed was analyzed with the result of trend analysis. The Seasonal Mann-Kendall test results showed that BOD concentrations had the downward trend at 10 unit watersheds, upward trend at 4 unit watersheds and no significant trend at 16 unit watersheds. And the LOWESS analysis showed that BOD concentration began to decrease after mid-2009 at almost all of unit watersheds having no trend in implementation plan watershed. It was estimated that TMDLs improved water quality in Geum River water system and the improvement of water quality was made mainly in implementation plan unit watershed and tributaries.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.436-446
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• 2015

It is suggested investigating method about the existing state of demand in this study. The total demand of 357 water amenity zones in 2014 is estimated based on the growth curve models. The effects of population density and distances between water amenity zones and metropolises populated over 1 million are investigated on each river system. The suitability like RMSE and MAPE of logistic and gompertz models are considered to select more suitable model for each water amenity zone. Demand for water amenity zones in 2014 is seemed to be rather high at Han Gang river system and Chungcheongbukdo after analyzing. The influence of population density is rarely effective except Geum Gang river system. The influence of metropolis on the demand for water amenity zones is higher at Geum Gang river system than others.