• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.792-802
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• 2009

The objective of this study is to construct the watershed management system with link of the non-point sources model and to estimate delivery ratio duration curves for various pollutants. For the total water pollution load management system, non-point source model should be performed with the study of the characteristic about non-point sources and loadings of non-point source and the allotment of pollutant in each area. In this study, daily flow rates and delivered pollutant loads of Nakdong river basin are simulated with modified TANK model and minimum variance unbiased estimator and SWAT model. Based on the simulation results, flow duration curves, load duration curves, and delivery ratio duration curves have been established. Then GIS analysis is performed to obtain several hydrological geomorphic characteristics such as watershed area, stream length, watershed slope and runoff curve number. As a result, the SWAT simulation results show good agreements in terms of discharge, BOD, TN, TP but for more exact simulation should be kept studying about variables and parameters which are needed for simulation. And as a result of the characteristic discharges, pollutants loading with the runoff and delivery ratios, non-point sources effects were higher than point sources effects in the small-scale test bed of Nakdong river basin.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.294-299
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• 2006

The Ministry of Environment in Korea has introduced Total Pollution Load Management System (TPLMS) in major 4 large rivers to protect the water quality from possible pollutants. In order to successfully achieve the TPLMS, the nonpoint source should be controled by applying the best management practices in highly polluted areas. Of the various nonpoint sources, the highways are stormwater intensive landuses because of its high imperviousness and high pollutant mass emissions. The EMC (Event Mean Concentration) is an important parameter to correctly determine the pollutant mass loadings from nonpoint sources. However, it has wide ranges because of various reasons such as first flush phenomenon, rainfall and watershed characteristics. Even though the EMC is closely related to the first flush phenomenon, the relationship have not proven until present. Therefore, in this paper, the dynamic EMC method will be introduced to clearly make the relationship between EMC and first flush phenomenon. Also by applying the dynamic EMC method to monitored data, we found that the highly concentrated stormwater runoff was washed off within 20~50 minutes storm duration. The first flush criteria for economical treatment was also determined to 5~10 mm (mean=7.4 mm) as a cumulative rainfall.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.487-496
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• 2019

Objective: The purpose of this study was to create soil contamination maps using QGIS (Quantum Geographic Information System) and suggest selection methods for soil pollution sources for preferential investigation in a soil contamination survey. Method: Data from soil contamination surveys over five years in Gyeonggi-do Province, South Korea (2013-2017) were used for making soil contamination maps and analyzing the density of survey points. By analyzing points exceeding the concern level of soil contamination, soil pollutant sources for priority management were identified and selection methods for preferred survey points were suggested through a study of the model area. Results: A soil contamination survey was conducted at 1,478 points over five years, with the largest number of surveys conducted in industrial complex and factory areas. Soil contamination maps for copper, zinc, nickel, lead, arsenic, fluoride, and total petroleum hydrocarbons were made, and most of the survey points were found to be below concern level 1 for soil contamination. The density of the survey points is similar to that of densely populated areas and factory areas. The analysis results of points exceeding the criteria showed that soil pollutant sources for priority management were areas where ore and scrap metals were used and stored, traffic-related facilities areas, industrial complex and factory areas, and areas associated with waste and recycling. According to the study of the model area, the preferred survey points were traffic-related facilities with 15 years or more since their construction and factories with a score of 10 or more for soil contamination risk. Conclusion: Soil contamination surveys should use GIS for even regional distribution of survey points and for the effective selection of preferred survey points. This study may be used as guidelines to select points for a soil contamination survey.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.201-213
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• 2007

In this study, the Batter Assessment Science Integrating point and Nonpoint Sources (BASINS 3.0)/window interface to Hydrological Simulation Program-FPRTRAN (WinHSPF) was applied for assessment of Soyang Dam watershed. WinHSPF calibration was performed using monitoring data from 2000 to 2004 to simulate stream flow. Water quality (water temperature, DO, BOD, nitrate, total organic nitrogen, total nitrogen, total organic phosphorus and total phosphorus) was calibrated. Calibration results for dry-days and wet-days simulation were reasonably matched with observed data in stream flow, temperature, DO, BOD and nutrient simulation. Some deviation in the model results were caused by the lack of measured watershed data, hydraulic structure data and meteorological data. It was found that most of pollutant loading was contributed by nonpoint source pollution showing about $98.6%{\sim}99.0%$. The WinHSPF BMPRAC was applied to evaluate the water quality improvement. These scenarios included constructed wetland for controlling nonpoint source poilution and wet detention pond. The results illustrated that reasonably reduced pollutant loadin. Overall, BASINS/WinHSPF was found to be applicable and can be a powerful tool in pollutant loading and BMP efficiency estimation from the watershed.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.528-536
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• 2016

The purpose of Total Pollution Load Control at Tributary is to obtain maximum improvement effect of water quality through finding the most impaired section of water-body and establishing the proper control measure of pollutant load. This study was implemented to determine the optimal management of reach, period, condition, watershed, and pollution source and propose appropriate reduction practices using the Load duration curve (LDC) and field monitoring data. With the data of measurement, LDC analysis shows that the most impaired condition is reach V (G4~G5), E group (flow exceedance percentile 90~100%) and winter season. For this reason, winter season and low flow condition should be preferentially considered to restore water quality. The result of pollution analysis for the priority reach and period shows that agricultural nonpoint source loads from onion and garlic culture are most polluting. Therefore, it is concluded that agricultural reuse of surface effluent (storm-water runoff with non-point sources) and low impact farming that includes reducing fertilization and controlling the height of drainage outlet are efficient water quality management for this study watershed.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1117-1127
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• 2018

This study was carried out to gather basic data for the purpose of proposing a plan to improve the water quality and conserve the aquatic ecosystem of the Singu Agricultural Reservoir in Korea. The water quality, sediment composition, benthic macroinvertebrate distribution, and fish distribution in the Singu Reservoir were analyzed; the reservoir is located close to farmlands, forests, villages, and livestock breeding areas. The results of the water quality analysis are as follows: 5.8~7.8 mg/L for dissolved oxygen, 13.1~20.7 mg/L for chemical oxygen demand, 14.4~18.8 mg/L for suspended solid, 0.96~1.70 mg/L for total nitrogen, 0.07~0.11 mg/L for total phosphorous, and $41.9{\sim}49.8{\mu}g/L$ for $chlorophyll-{\alpha}$. In total, 75 benthic macroinvertebrate specimens belonging to 4 classes, 7 orders, 14 families, and 17 species were recorded. The ecological scores of the benthic macroinvertebrate communities ranged from 11 to 23. Fish specimens recorded belonged to two families and four species. The dominant fish species were Carassius auratus and Pseudorasbora parva, both of which are water-pollutant tolerant species.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.431-440
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• 2014

To propose the improvement and management plans to strengthen the pollutant removal efficiency of dam reservoir's constructed wetlands(CWs), the operation status and configuration of CWs (including water depth, operational flow, water flow distribution, residence time, and pollutant removal efficiency, aspect ratio, open water/vegetation ratio etc.) were analyzed in 10 major wetlands constructed in dam reservoirs. The pollutant concentrations in the inflows of the studied CWs were lower than those of American and European constructed wetlands. Especially, organic matter concentrations in all of inflows were below 3 mg/L(as BOD) due to advanced treatment of sewage disposal plant and an intake of low concentration water during dry and normal seasons. The average removal efficiency of total nitrogen(TN) and total phosphorus(TP) for 10 CWs ranged from 7.6~67.6%(mean 24.9%) and -4.9~74.5%(mean 23.7%), respectively, showing high in wetlands treating municipal wastewater. On the other hand, the removal efficiency of BOD was generally low or negative with ranging from -133.3 to 41.7%. From the analysis of the operation status and configuration of CWs, it is suggested that the low removal efficiency of dam reservoir's CWs were caused by both structural (inappropriate aspect ratio, excessive open water area) and operational (neglecting water-level management, lack of facilities and operation for first flush treatment, lake of monitoring during rainy events) problems. Therefore, to enable to play a role as a reduction facility of non-point source(NPS) pollutants, an appropriate design and operation manuals for dam reservoir's CW is urgently needed. In addition, the monitoring during rainy events, when NPS runoff occur, must be included in operation manual of CW, and then the data obtained from the monitoring is considered in estimation of the pollutant removal efficiency by dam reservoir's CW.

• Journal of Wetlands Research
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• v.20 no.1
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• pp.43-53
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• 2018

Laguna Lake is the largest inland fresh water body in the Philippines. It primarily serves as a site for aquaculture, hydropower, transportation, and water supply industries. Due to Laguna Lake's diverse functionalities, competition among water users became prominent. Water quality began to deteriorate due to various pollutant contributions in this process, thereby affecting the soundness of the aquatic ecosystem. This study was conducted to evaluate the current water quality management policy from the viewpoint of ecological environment through the evaluation of the water quality of Laguna Lake. Concentrations of water pollutants such as ammonia ($NH_3$), biochemical oxygen demand (BOD), chloride ($Cl^-$), pH, and total suspended solids (TSS) exceeded the water quality standards of the Philippines' Department of Environment and Natural Resources (DENR). The water quality of the lake was also affected by the pollutant load due to agriculture and urban stormwater runoff in the watershed. The salinity and contaminated water from Pasig River also affected the water quality of Laguna Lake. Long-term water quality analysis showed that the water quality of Laguna Lake is also influenced by rainfall-related seasonal variations. The results of the water quality analysis of Laguna Lake indicated that the environmental management techniques of the Philippines should be changed from the conventional water management into an integrated watershed management scheme in the future. It is therefore necessary to study and introduce advanced watershed management measures in the Philippines based from the policies of other developed countries.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.26-36
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• 2009

Combined sewer system (CSS) has been built in the most urban areas across the nation. During dry weather conditions, CSS works fine. But during heavy rain storms, combined sewage frequently overflows into the stream. This study simulated the hydrologic cycle and pollutant loads (BOD, SS, TN and TP) in the Mokgamcheon watershed considering combined sewer overflows (CSOs). PC storm water management model (PCSWMM) was used for continuous simulation and CSOs are considered using the flow divider. Sensitivity analysis, calibration and verification for water quantity and quality are carried out. To verify CSOs, field measurements of CSOs are compared with simulated results. As a result, 41.3% of precipitation flows into the stream directly and 1.1% of water supply flows into stream as CSOs. 6.5% of BOD total loads, 12.0% of SS, 13.6% of TP, and 29.2% of TN are from CSOs. This result will be effective to the integrated watershed management for sustainability.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.704-716
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• 2018

The aim of this study is to examine the characteristics analysis of the discharge and water quality based on TPLMS (Total Pollution Load Management System) in the Jinwi River unit basin, and to propose a management plan by selecting the point that needs improvement of water quality in order to achieve the target water quality. We evaluated the discharge and water quality characteristics, statistical analysis, daily delivery load and daily delivery density, grade classification, for 14 total pollution load site's from 2014 to 2016 year in Jinwi river unit basin. The average discharge of Jinwi river unit basin is $22.411m^3/s$ and discharge of Hwangguji River is 32.8% and the water quality characteristics along the tributary river were clarified spatially. As the result, it was analyzed that Seongeun River is an indirect indicator of organic pollutants, Gwanri River is a seasonal factor, Osan River and Hwangguji River both affect water quality. Estimation of delivered pollutant loads at the HG-3 site was 6,470.4 BOD kg/day, 6,846.7 TN kg/day and delivered pollutant loads density increased to $220.9BOD\;kg/day/km^2$, $22.4TP\;kg/day/km^2$ at the HG-4 site. This result demonstrates that the total pollution load site needed to improve water quality of the Jinwi River unit basin was HG-3 site.