• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.651-658
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• 2005

The Non-parametric Analysis is powerful in data test especially for the non- normality water quality data. The data at three monitoring stations of the Tam-Jin River were evaluated for their normality using Skewness, Q-Q plot and Shapiro-Willks tests. Various constituent of water quality data including temperature, pH, DO, SS, BOD, COD, TN and TP in the period of January 1994 to December 2004 were used as dataset. Shapiro-Willks normality test was carried out for a test 5% significance level. Most water quality data except DO at monitoring stations 1 and 2 showed that data does not normally distributed. It is indicating that non-parametric method must be used for a water quality data. Therefore, a homogeneity was conducted by Mann-Whitney U test (p<0.05). Two stations were paired in three pairs of such stations. Differences between stations 1, 2 and stations 1, 3 for pH, BOD, COD, TN and TP were meaningful, but Tam-Jin 2 and 3 stations did not meaningful. In addition, a narrow gap of the water quality ranges is not a difference. Categories in which all three pairs of stations (1 and 2, 2 and 3, 1 and 3) in the Tam-Jin River showed difference in water quality were analyzed on TN and TP. The results of in this research suggest a right analysis in the homogeneity test of water quality data and a reasonable management of pollutant sources.

• Journal of Korea Water Resources Association
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• v.51 no.12
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• pp.1237-1245
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• 2018

We developed the assessment method for weekly groundwater resources management vulnerability. To consider the effect of precipitation on groundwater level, we calculated correlation coefficient between groundwater level and precipitation applying critical infiltration concept. We developed the vulnerability assessment criteria and calculated weights for criteria using the entropy method. Weekly groundwater resources management vulnerability of small administrative districts were estimated using developed method in this research. The developed method can be a basis for the establishment of the spatio-temporal groundwater resources management plan.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.160-162
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.149-152
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• 2012

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.222-222
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• 2020

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.743-753
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• 2012

The hydrologic models, capable of simulating groundwater recharge for long-term period and effects on it of crops management in the agricultural areas, have been used to compute groundwater recharge in the agricultural fields. Among these models, the Soil and Water Assessment Tool (SWAT) has been widely used because it could interpret hydrologic conditions for the long time considering effects of weather condition, land uses, and soil. However the SWAT model couldn't represent the spatial information of Hydrologic Response Unit (HRU), the SWAT HRU mapping module was developed in 2010. With this capability, it is possible to assume and analyze spatio-temporal groundwater recharge. In this study, groundwater recharge of rate for various crops in the Mandae stream watershed was estimated using SWAT HRU Mapping module, which can simulate spato-temporal recharge rate. As a result of this study, Coefficient of determination ($R^2$) and Nash-Sutcliffe model efficiency (NSE) for flow calibration were 0.80 and 0.72, respectively, and monthly groundwater recharge of Mandae watershed in Haean-myeon was 381.24 mm/year. It was 28% of total precipitation in 2009. Groundwater recharge rate was 73.54 mm/month and 73.58 mm/month for July and August 2009, which is approximately 18 times of groundwater recharge rate for December 2009. The groundwater recharges for each month through the year were varying. The groundwater recharge was smaller in the spring and winter seasons, relatively. So, it is necessary to enforce proper management of groundwater recharge during droughty season. Also, the SWAT HRU Mapping module could show the result of groundwater recharge as a GIS map and analyze spatio-temporal groundwater recharge. So, this method, proposed in this study, would be quite useful to make groundwater management plans at agriculture-dominant watershed.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.211-211
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• 2020

The concept of virtual water has been largely applied in the study of regional, national, and global water flows with particular emphasis on water scarcity. Despite water traditionally being managed locally, certain global forces influence the local water resource scarcity/availability and hence virtual water exchanges worldwide. It is therefore of necessity that the significant forces be examined to understand the relationship between available water in a region and the variability and trends in environmental, social, and economic factors that are of utmost importance in the formulation of water resources management policies. This study therefore reviewed recent literature from 2003 - 2019 to determine the significant indicators of virtual water trade at different spatiotemporal levels. The study examined and compared the major approaches to virtual water trade flows accounting, and also identified and discussed policy implications and future research options concerning the analysis of virtual water trade. Available information has shown that virtual water trade is significantly influenced by economic (GDP, Demand-Supply of goods and services), geographical (Distance), institutional (population) and environmental (water availability, arable land, precipitation) factors. Reports further show that the selection of a given approach for virtual water trade flows accounting will depend on the scope of the study, the available datasets, and other research preferences. Accordingly, this study suggests that the adoption of multidisciplinary approaches to virtual water trade, taking into consideration the spatial and temporal variations in water resources availability and the complexity of environmental and socioeconomic factors will be pivotal for establishing the basis for the conservation of water resources worldwide.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.373-379
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• 2006

We investigated the relationship of the organic pollutant index in wastewater where the high percentages of an organic load to a water body was found. Measuring of TOC was to identify the relationship with COD and BOD which were used already. The correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD were effected by the types of industry such as paper, textile, chemical, food and metal industries. In food industry it was found that the highest correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD as 0.967, 0.969 and 0.990, respectively. There is low correlation coefficient in many cases. Hence it was impossible that the use of TOC for the water standard or monitoring instead of COD and BOD directly. However it can be used as alternative index to management a water process in the case of waste water where there was found high correlation coefficient of TOC/ COD, BOD/COD and TOC/BOD. It was sure that the water quality of river body can be protected if we use these the relationship among organic index.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.4
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• pp.281-291
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• 2012

In this study, WET (whole effluent toxicity) test with Skeletonema costatum, Tigriopus japonicus and Paralichthys olivaceus and ERA (environmental risk assessment) were conducted to assess the unacceptable effect on marine ecosystem by emitting the treated discharge water from 'ARA Plasma BWTS' BWMS (ballast water management system) using filtration, Plasma and MPUV module. 34 psu treated discharge water from ARA Plasma BWTS shown slight chronic toxicity effect on the P. olivaceus ($7d-LC_{50}{\Rightarrow}100.00%$ treated discharge water, $7d-LC_{25}{\Rightarrow}85.15%$ treated discharge water). Bromobenzene, chlorobenzene and 4-chlorotoluene in 34 psu treated discharge water from ARA Plasma BWTS were higher than in the background original content of seawater. The PECs (predictive environmental concentrations) of bromobenzene, chlorobenzene and 4-chlorotoluene calculated by MAMPEC (marine antifoulant model to predict environmental concentrations) program (ver. 3.0) were 3.34E-03, 2.10E-03 and 1.73E-03 ${\mu}g\;L^{-1}$, respectively and PNECs (predicted no effect concentrations) of them were 1.6, 0.5 and 1.9 ${\mu}g\;L^{-1}$. The PEC/PNEC ratio of bromobenzene, chlorobenzene and 4-chlorotoluene did not exceed one and 3 substances did not consider as persistence, bioaccumulative and toxic. Therefore, it was suggested that treated discharge water from ARA Plasma BWTS did not pose unacceptable effect on marine ecosystem.

• Journal of Korea Water Resources Association
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• v.38 no.9 s.158
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• pp.779-790
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• 2005

A concept of sustainable development has become a major concern in international debate on water resources development and environmental conservation. Although sustainable water resources development and management takes a significant amount of concern in the development research, its applicability has not been insufficient in practices. The purpose of this study is to address a definition of sustainable water resources development and management and to illustrate relevant indicators. The study has also attempted to develop localized indicators hence to assess an availability of water resources development and management and to evaluate the water resources in Korea with the indicators which have been developed in other countries.