• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.13-20
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• 2013

An emergy concept was used to evaluate the contributions of the Youngsan River Estuary to the Korean economy from systems and ecosystem service perspectives. Total emergy input to the estuary was $9.42{\times}10^{20}$ sej/yr with the chemical potential of river inflow accounting for 73% of the total and tidal energy for the remaining 27%, reflecting the unique environmental characteristics of estuaries where rivers meet sea. From the systems perspective, the estuary ecosystem contributed 179.9 billion em\/yr (14.91 million em\/ha/yr or 13,526 em$/ha/yr). Four ecosystem services of the Youngsan River Estuary were selected for the emergy evaluation: fishery production, pollutant removal, aesthetic function, and scientific research information. Aesthetic function contributed the most to the Korean economy with 179.9 billion em\/yr, followed by fishery production (101.1 billion em\/yr), pollutant removal (32.6 billion em\/yr), and scientific research information (934 million em\/yr). Emergy-based values of the selected ecosystem services of the estuary were higher than those calculated by economic methodologies.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.254-259
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• 2012

The discharge characteristics of Volatile Organic Compounds (VOCs) from seven wastewater treatment plants and two industry drains at Nakdong River basin were investigated. Four Sampling campaigns were conducted between May 2008 and November 2008, and tested for 17 VOCs. As results, eight VOCs were detected at some sampling sites, but their concentration levels were low; 0.19~3.41 ${\mu}g/L$, dependent on each sampling location and substance. However, proper management plans such as supervising and monitoring systems for VOCs are needed to control those pollutants since VOCs might affect human health as well as aquatic ecosystems with extremely low concentration levels.

• Animal Systematics, Evolution and Diversity
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• v.2 no.2
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• pp.1-12
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• 1986

Genetic and morphological variation among seven populations of two species of the genus Liobagrus that had been collected from six separate river systems in Korea were analyzed by means of starch electrophoreiss and discriminant function analysis . The degree of genic variation among three population of L.andersoni was P=21.3%, H=0.068 , and that of four population of L.mediadiposalis was P=16.3%, H=0.560. Rogers' gentic similarity coefficient (S) of L.andersoni and L.mediadiposalis were S=0.592 , S=0.675 respectively. In morphometric characters of L. andersoni, the population from Kum River was distinctly different from other conspecific populations.

• Journal of Environmental Health Sciences
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• v.15 no.1
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• pp.33-49
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• 1989

Pollution in the rivers has received considerable attention in recent years, particullary with reference to the effect due to increasing concentration of heavy metals. The metals are toxic to the ecosystem as a whole and to man in particular, since he is at the end of a variety of food chains by virture of his varigated diet. In addition, numerous laboratory tests have established that certain metals, such as Cd, pose a threat to a wide variety of aquatic organisms at concentrations as low as a few $\mu$g/1. Before the biological effects of heavy metals in impacted ecosystems can be completely assessed, however it is necessary to provide data on the concentration of heavy metals in such systems. This study was performed to investigate the concentration level of heavy metals in water, fish and sediments from upstream ($S_1-S_4$) to downstream ($S_5-S_9$) of the Mankyung river. Samples of water, fish, and sediments were collected along the tributaries of the Mankyung from September to October in 1987 and analyzed for lead, cadmium, copper, and zinc by atomic absorption spectrophotometer. From the data presented in this study, we can infer that the concentrations of the heavy metals investigated both in water and sediments are similar to those found in literature for unpolluted regions. The results obtained from the analysis of the edible tissue of the C. auratus show low concentration levels of the four heavy metals investigated. We conclude that the area is still relatively unpolluted and recommended continuing the monitoring of heavy metal concentrations to improve our understanding of their cycle in the river environment.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.305-305
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• 2022

A better approach for assessing meteorological drought occurrences is increasingly important in mitigating and adapting to the impacts of climate change, as well as strategies for developing early warning systems. The present study defines meteorological droughts as a period with an abnormal precipitation deficit based on monthly precipitation data of 18 gauging stations for the Han River watershed in the past (1974-2015). This study utilizes a Bayesian parameter estimation approach to analyze the effects of climate change on future drought (2025-2065) in the Han River Basin using the Coupled Model Intercomparison Project Phase 6 (CMIP6) with four bias-corrected general circulation models (GCMs) under the Shared Socioeconomic Pathway (SSP)2-4.5 scenario. Given that drought is defined by several dependent variables, the evaluation of this phenomenon should be based on multivariate analysis. Two main characteristics of drought (severity and duration) were extracted from precipitation anomalies in the past and near-future periods using the copula function. Three parameters of the Archimedean family copulas, Frank, Clayton, and Gumbel copula, were selected to fit with drought severity and duration. The results reveal that the lower parts and middle of the Han River basin have faced severe drought conditions in the near future. Also, the bivariate analysis using copula showed that, according to both indicators, the study area would experience droughts with greater severity and duration in the future as compared with the historical period.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.673-678
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• 2011

Water samples from several wastewater treatment plants and two industry drains in Gyeongsangbukdo were investigated for concentration levels of micropollutants. Samples were taken totally four times from May to November of 2008 and tested for seven factors including pesticide, 1,4-Dioxane and Perchlorate which had been big issues for Nakdong river because of their contaminations. As results, 2,4-D, Alachlor, and BEHA were not detected while BEHP was detected at some sampling sites. 1,4-Dioxane and Perchlorate were also detected in wide ranges from several sampling sites. Therefore, continuous supervising and monitoring systems needed to be invested for proper management for micropollutants since those micropollutants could affect human health and aquatic system with low concentration levels.

• Journal of Species Research
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• v.1 no.2
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• pp.240-248
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• 2012

We used a non-invasive technique with microsatellite primers to investigate genetic variation among Eurasian otters Lutra lutra in eastern South Korea. We collected twenty two otter spraints in January and six in August 2008. We used spraints from five dead otters from five different river systems for the present genetic analysis. We extracted DNA from 20 spraints from the January sample. Ten microsatellite primers (Lut435, Lut453, Lut457, Lut604, Lut615, Lut701, Lut715, Lut717, Lut733, and Lut832) for Eurasian otters were tested, and four loci were successfully amplified for further analyses. The results of genotyping the otter population with microsatellite loci lead to the identification of 9 individuals from the Ungokcheon Stream. The Ungokcheon population also showed a genetic structure represented by the Hardy-Weinberg equilibrium.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.63-67
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• 2012

A comparative study of bile acid components from four lamprey species revealed that mature male chestnut lamprey Ichthyomyzon castaneus can produce 3 keto petromyzonol sulfate (3kPZS) while mature males of Pacific lamprey Lampetra tridentata, river lamprey Lampetra fluviatilis and American brook lamprey Lethenteron appendix produce petromyzonol sulfate (PZS). Identification of 3kPZS from a group of ancient lamprey species and of PZS from recently derived species led to a speculation that differentiation of bile acid biosynthetic systems has taken place during the course of evolution. Further studies on the biological functions of different bile acids in the adult lampreys are required to understand the evolution of chemical communication in lampreys.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.423-430
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• 2008

As of September 2008,45 Automatic Water Quality Monitoring Systems (AWQMS) have been installed at different sites on the 4 rivers to detect early the presence of pollutants in water and to issue an alarm. We count the number of issuing alarms by AWQMS, however, we will find the alarm has hardly been issued. The reasons for the scarcity of alarm issue are extensively being examined. The National Institute of Environmental Research attributes wrong alarm criteria for each AWQMS station to one the reasons. In this study, a suggestion has been made to modify the current alarm criteria to correspond with characteristics of river water quality. The current system with only two criteria (low and high) should be replaced as four-criteria systems (low, medium, high, and severe) based on cases of other advanced countries and stream conditions of Korea. The highest value of data collected for 5 years was suggested as the alarm criteria for each parameter. Meanwhile the alarm criteria for VOCs, phenol and heavy metals were established as same as drinking water quality criteria.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.612-615
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• 2007

Water quality modelling is an ideal tool of simulating physical, chemical and biological changes occurring in water systems. It has been utilized in a number of GIS-based water quality management and analysis applications. However, there is a need of a decision making process to translate the modelling result into an understandable form thereby implement the modelling results to the real world. This paper outlines a new water quality index called the QUAL2E's water quality index (QWQI) based on the water quality modelling using QUAL2E. The development mainly includes four steps: variable selection, sub-index development, weight assignment and sub-index aggregation. An experiment of applying the index and GIS to the Sapgyo River in Korea was implemented. Different from other water quality indices for general water uses, the index is specifically used for the simulated water quality indicators. The index can provide a simple and easy-to-understand decision support. Furthermore, interfacing with GIS, the decision analysis can be performed within a spatial environment. However, more study needs to be made in the future including the improvement of aggregation function.