• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.15-26
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• 2020

There are fifteen non-point pollution management areas in Korea and three of them (Doam lake, Daegi district and Golji-cheon) are located in the upstream of the Namhan river watershed. Many efforts to reduce non-point sources (NPS) pollution have been conducted, however, water quality pollution in the watershed is still serious. To solve these problems, it is a priority to grasp water quality using statistical techniques. In this study, a trend analysis was conducted to evaluate the effect of NPS management in the watershed. The long-term trends from 1996 to 2018 of water quality properties were analyzed using data collected from the water environment information system. Seventeen monitoring stations were selected along the main stream in Namhan river basin. Monthly water quality properties (BOD, COD, TN, TP, TN/TP ratio, Conductivity, SS and Chlorophyll-a) were collected and analyzed by Mann-Kendall test and LOWESS. The results showed that the Conductivity tended to increase in all regions and was the highest level in Jijangcheon. Organic pollution such as BOD and COD tended to increase in the Jungseon area. SS did not show a large tendency, but it showed high concentration in the Doam watershed. In all regions, 40% of water quality properties showed a tendency to 'UP', 15% of water quality properties tended to 'DOWN', and 46% indicated no tendency. In order to determine the cause of this, additional research and measures for improvement are necessary. This study will be used for the establishment of water quality policy in the future.

• Journal of Environmental Impact Assessment
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• v.25 no.3
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• pp.222-232
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• 2016

Water Footprint is utilized to analyze direct and indirect water consumption for sustainable water resource management. This study aims to understand potential applicability of water footprint concept by analyzing the status of water consumption and related water policies in Seoul. We analyzed a direct gray water footprint and the blue water footprint in Seoul affected by the social and economic characteristics of the consumers in the city. In particular, in order to analyze the blue water footprint represented by both surface and underground water for the provision and consumption of products, we calculated the actual water consumptions of surface and underground water for 25 districts in Seoul. Our analysis in consideration of population and households indicates that Jung-gu has the highest blue water footprint followed by Jongro-gu, Gangnam-gu, Yongsan-gu, and Seocho-gu. Gray water footprint was calculated by estimating the amount of water for purifying wastewater to meet the water quality standard (above BOD 3.5ppm) for each district. As a result, Jung-gu has the highest gray water footprint, followed by Jongro-gu, Gangnam-gu, Yongsan-gu, Seocho-gu, and Youngdeungpo-gu. Our study suggests the potential value of using water footprint concept to complement the current limitations of water use management focusing on water supply control. We expect that our analysis will provide an important basis for considering water use management which is economically and socially more resilient and sustainable.

• Journal of Korean Society on Water Environment
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• v.37 no.5
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• pp.381-397
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• 2021

Off-flavor materials (geosmin and 2-methylisoborneol (2-MIB)) produced by microorganisms, such as, cyanobacteria and actinomycetes, cause freshwater use problems worldwide. Due to unpleasant taste and odor, these microorganisms have raised issues especially in drinking water resources. Recently, there has been increasing concern about 2-MIB and causal cyanobacteria, namely, Pseudanabaena, in Korea. However, material production and ecological dynamics remain largely unexplored. This study reviewed the distribution of Pseudanabaena, its species diversity, and the research trend of molecular ecology related to 2-MIB production in Korea. Based on published literature, we found that seven species of Pseudanabaena which include P. mucicola, P. limnetica, P. redekei, P. catenata, P. galeata, P. yagii, and P. cinerea appeared to occur in a variety of Korean water systems. All of these Pseudanabaena species were found in the North-Han River system (Lakes Soyang, Chuncheon, Uiam, and Paldang). Some of these species were also detected in other watersheds, but the precise species diversity was not identified. Species belonging to the Pseudanabaena genus are hard to classify through general microscopic alpha taxonomy, due to their very small cell size and similar morphological characters. Moreover, the potential of 2-MIB production cannot be detected by microscopic observation. Combining molecular ecological techniques, such as, environmental genomic materials (eDNA, eRNA) analyses to conventional methods could be useful to better understand the off-flavor material production and dynamics, thereby providing more efficient management strategies of freshwater systems.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.1008-1015
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• 2010

Discharged pollution load is varied as rainfall changes in the area with combined sewer system. Changes in discharged pollution load are directly related with those of sewer transfer flow. Therefore, it is important to identify the pattern of sewer transfer flow for the analysis of changes in discharged pollution load. This study reviewed the type of distribution of sewer transfer flow for 17 sewage treatment plants and developed simple formular to estimate sewer transfer flow as rainfall changes. 11 facilities showed to have some relation with rainfall in the change of sewer transfer flow but 6 facilities to have no relation. Relationships between rainfall amount and sewer transfer flow showed that 6 facilities out of 11 had relatively strong relationships above R2=0.5, which were considered to be affected directly by rainfall changes. The formular which explain the relationship between rainfall and sewer transfer flow can be applied in the analysis of rainfall effects on discharged pollution load, therefore, the more appropriate evaluation will be done.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.537-545
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• 2016

In order to cope with the new and strict government regulations for turbid water discharge from construction sites, this study tested whether synthetic fiber filters can replace conventional best management practices. The filter efficiency was about 10 to 60% with a varying filter depth of 5 to 15cm, presuming extreme storm flow conditions to be in the range of 800 to 1500m/day of filtration rates. Fiber filter acts exactly like a granular filter, i.e. the separation efficiency is directly and inversely proportional to filter depth and rate, respectively. Based on the operational data, we suggested the Log-Log design relationship, which can be used to determine the filter depth and area. Compared to the widely used gravel filter which treats the turbid water at the construction site, about 20% higher efficiency was obtained under similar operating conditions. Cleaning the filter through a simple hand-washing method at the time of break-through, achieved about 90% soil recovery.

• Journal of Environmental Policy
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• v.2 no.1
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• pp.1-29
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• 2003

This paper examines the dynamics of environmental policy development in Korea by reviewing some of the ways on how the policy windows have been opened. There are a lot of theoretical arguments about the major factors influencing policy development or changes. Many scholars have believed that severe pollution accidents or salient environmental episodes might have been the main motivation of environmental policy development. This line of argument seems valid, especially with the water pollution control policy in Korea. Water pollution control programs had rapidly expanded along with the series of water pollution accidents in the tap water sources from the late 1980s to mid-1990s. However, regarding other major env. issues, various other factors have played more important roles in the development of the relevant policies. In case of air pollution control policy international sport events such as, 1986 Asian Games, 1988 Summer Olympics, and 2002 World Cup Competition, have contributed for the development. The municipal solid waste management policy partly owed its development to the introduction of local autonomy system in the mid-1990s. Even the foreign currency crisis occurring in December 1997 helped the policy paradigm shift from rigid supply-oriented to soft demand-oriented approaches. After closely looking at the dynamics of environmental policy development in Korea, this paper tries to identify the logical background of the observed outcomes.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.249-268
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• 1997

This Study developed 'Environment Management Integrated Leader(EMIL)' program and evaluated the effect of the Program. The procedure of EMIL program development is as follows; 1) Identifying the training needs Through the interview and discussion with corporate environmental staff and research members, training need are collected. 2) Setting the training objectives 30 objectives are developed through specifying and organizing the training needs. 3) Determining the scopes of the program This program consists of the four scopes. First, the scope of Environmentally Acceptable Management is developed based on ISO 14000 and certification of environmentally friendly business. Second, the scope of Environmentally Acceptable Technology includes air pollution, water pollution, solid wasted management, and pollution prevention. Third, the scope of Integrated Environmental Management focuses on master plan, green marketing, green production, and green accounting. Finally, the scope of Integrated Environmental Concepts focuses on food pollution, environmental activities, and bio-diversity. 4) Selecting the training methods Various methods are used such as off-site visits, exercises, case study, workshop, discussion, role-playing as well as lecture. 5) Implementing the program 49 trainees participated the program for 6weeks. All trainees are working for D. Company Group. 6) Measuring training effects To evaluate the effects of the program, pre-post training evaluation method is used. The results are highly significant at all 4 scopes by the p<.01. This study has some implications in order to establish the environmental management climate. First, the development of new environmental education program for management is necessary. Second, Vast investment are required. Third, more systematic approaches are desired in environmental education. Lastly, more customized program development and implementation to fit in industries will accelerate the expansion of environmental concept.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.1-8
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• 1998

Chungju reservoir is a multipurpose dam lake located at the upstream of Nm Han river and known as having the biggest watershed and the second water volume in korea. Conclusions are made as follows. 1. Environmental characteristics of the reservoir appear to be as follows. Chungju reservoir has long hydaulic retention time, 60-160 days. Water column has oxygen depletion zone in hypolimnion. Chungju reservoir is found to be in the midst of eutrophication. Chlorophyll-a and other physical parameters are found to be significantly dependent. 2. Nitrogen to phosphorus ratio was 50-350 for the water samples taken from the reservoir in 1996. It is very important clue for water quality management in relation to phytoplankton growing kinetics. Variations in chlorophyll-a contents appear to be related closely to total phosphorus concentration.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.535-539
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• 2009

Evapotranspiration (ET) is one of the main factor to understand the hydrologic cycle on land surfaces of entire globe. It accounts for about 65% of precipitation returning to the atmosphere. Accurate estimation of the ET is essential to many applications of water resources management, hydrology, meteorology, climatology, and agriculture. Over the past few decades, there have been extensive efforts to develop and validate a number of ET models. Priestley-Taylor (P-T) and Food and Agriculture Organization Penman-Monteith (P-M) models are generally recognized as simple, but great operational approaches to estimate ET over different land cover types. In this study, we compare/validate different models of increasing complexity, P-T, P-M, and Common Land Model (CLM) in croplands, IA.

• Journal of Environmental Impact Assessment
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• v.20 no.4
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• pp.435-442
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• 2011

In this study, a regression model was developed for prediction of inflow temperature to support an effective thermal stratification simulation of Yongdam Reservoir, using the relationship between gaged inflow temperature and air temperature. The effect of reproductability for thermal stratification was evaluated using EFDC model by gaged vertical profile data of water temperature(from June to December in 2005) and ex-developed regression models. Therefore, in the development process, the coefficient of correlation and determination are 0.96 and 0.922, respectively. Moreover, the developed model showed good performance in reproducing the reservoir thermal stratification. Results of this research can be a role to provide a base for building of prediction model for water quality management in near future.