• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.4
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• pp.1-10
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• 2022

A vegetative filter strip (VFS) is one of the best management practices (BMPs) to reduce pollutant loads. This study aims to assess the effectiveness of VFS in dense upland field areas. The study areas are agricultural fields in the Maedae (MD), Gaa (GA), and Jaun (JU) watersheds, where severe sediment yields have occurred and the Korean government has designated them as non-point management regions. The agricultural fields were divided into three or four clusters for each watershed based on their slope, slope length, and area (e.g., MD1, MD2). To assess the sediment trapping (STE) and pesticide reduction efficiency (PRE) of VFS, the Vegetative Filter Strip Modeling System (VFSMOD) was applied with three different scenarios (SC) (SC1: VFS with rye vegetation; SC2: VFS with rye vegetation and a gentle slope in VFS range; and SC3: VFS with grass mixture). For SC1, there were relatively short slope lengths and small areas in the MD1 and GA3 clusters, and they showed higher pollutant reduction (STE>50%, PRE>25%). For SC2 and SC3, all clusters in GA and some clusters (MD1 and MD3) in MD show higher pollutant reduction (>25%), while the uplands in JU still show a lower pollutant (<25%). With correlation analysis between geographic characteristics and VFS effectiveness slope and slope length showed relative higher correlations with the pollutant efficiency than a area. The results of this study implied that slope and slope length should be considered to find suitable upland conditions for VFS installations.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.287-295
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• 2017

In this study, rainfall runoff characteristics according to peak concentration were analyzed using the water quality and flow data in the Geumho river, and the direction of nonpoint source management such as monitoring and management period by pollution source was derived. Peak Water Quality Concentration is the concept that utilizes the extreme value as the concentration of non-point pollution control standard with the highest water quality in the rainwater runoff. Using this method, the evaluation factors such as cumulative precipitation(total precipitation), peak water quality concentration, cumulative precipitation up to peak water quality concentration, time to peak water quality concentration, and EMC to peak water quality concentration were examined and long- Rainfall runoff characteristics of nonpoint sources were analyzed. The results of the analysis suggested proper monitoring and management method to manage nonpoint source.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.15-32
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• 2011

This study was carried out to investigate the soil characteristics and propose the management for the Monument Beobsoo Marsh, Korea. The soil properties of O.M, $Ca^{2+}$, $Na^+$ and CEC were higher and the soil properties of pH_{1:5}$ and $P_2O_5$ were lower the studied sites than other marsh sites in Korea. Although the Heavy metals such as Pb, Hg, Cd, Cu, Zn, Cr and As were lower compare to the safety standard of soil pollution in Korea, the overall conservation management plan based on long-term monitoring should be considered just because it varied by the point and non-point source pollution within the studied marsh. The source of water pollution varied due to non-point polluting origins such as sewage inlet, degraded terrain for agriculture, fishing sites, sites of removed water grasses, pesticides, chemical fertilizers, as well as fallen leaves. The creation of an artificial marsh is recommended due to the soil environment of the studied sites may be changed owing to the accumulated contaminants from the sources of both of point or non-point contaminants. The establishment of the zones of core, buffer and transition which is basic management structure of the UNESCO MaB could be applied to manage the studied site. Simultaneously the promotion of voluntary participation and education of the local residents are needed.

• Journal of Korean Society of Rural Planning
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• v.7 no.1 s.13
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• pp.77-88
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• 2001

In order to evaluate the applicability of GWLF model which can efficiently estimate non-point and point source pollutant loadings in rural watershed including urban district, the model was applied to an experimental watershed. The model was calibrated using observed data such as daily runoffs, sediment yields, T-N, and T-P. Simulated daily runoffs and sediment yields by the model using calibrated parameters were in food agreement with the observed data. There were difference between the simulated and observed nutrient loading which was considered resonable. The simulated results by the model showed that T-N, T-P and sediment yields were dependent on the amount of stream runoff discharge and land use. GWLF model is believed to applicable to estimate amount of pollutant loading of non-point source pollution for the water qualify control of agricultural watersheds.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.686-692
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• 2012

This study illustrates how to design and evaluate a non-point sources management detention pond using SWMM. In particular, special attention is given to the orifice design. In SWMM, orifice properties that need to be defined include its height above the bottom of the storage unit, its type, its geometry and its hydraulic properties. Among the various characteristics of orifice, the orifice hole size which is closely related to hydraulic retention time is focused in this study. Sensitivity analysis of orifice size in annual non-point sources reduction efficiency is carried out. In addition, a methodology which can be used to design a virtual junction in SWMM has been proposed to quantify water quality improvement triggered by the detention pond installation. As a result, it is recommended that a detention outlet should be designed to be about 2 to 3 days of hydraulic retention time.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.96-99
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• 2003

Land cover map is a typical GIS database which shows the Earth's physical surface differentiated by standardized homogeneous land cover types. Satellite images acquired by Landsat TM were primarily used to produce a land cover map of 7 land cover classes; however, it now becomes to produce a more accurate land cover classification dataset of 23 classes thanks to higher resolution satellite images, such as SPOT-5 and IKONOS. The use of the newly produced high resolution land cover map of 23 classes for such activities to estimate non-point sources of pollution like water pollution modeling and atmospheric dispersion modeling is expected to result a higher level of accuracy and validity in various environmental monitoring results. The estimation of pollution from non-point sources using GIS-based modeling with land cover dataset shows fairly accurate and consistent results.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.11-22
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• 2002

This study analyzes the river system and water quality conditions of Bukchun in order to establish a basic plan for Preparing a natural learning and experimental area of environmental ecosystem in Bukchun, Gyeongju. It also tries to establish an integrated plan for water management of Bukchun stream based on water contaminants. In addition, after analysing the water quality at 13 points during the non-rainy season, the effluent of municipal wastewater was of relatively better quality with I ~ II grade, below the water quality standard of the river, except in points near Samsung apartments. However, analysing the Hyeongsangang and the effluent of Bomunho and Duckdongdam in rainy season, the water quality was II ~ III grade according to environmental standard. The water Quality of those samples was strongly dependent of non-point source.

• Magazine of the Korean Society of Hazard Mitigation
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• v.9 no.2
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• pp.52-60
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• 2009

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1271-1276
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• 2020

The geometrical efficiency of a source-to-detector configuration is considered to be necessary in the calculation of the full energy peak efficiency, especially for NaI(Tl) and HPGe gamma-ray spectroscopy detectors. The geometrical efficiency depends on the solid angle subtended by the radioactive sources and the detector surfaces. The present work is basically concerned to establish a new mathematical approach for calculating the solid angle and geometrical efficiency, based on conversion of the geometrical solid angle of a non-axial radioactive point source with respect to a circular surface of the detector to a new equivalent geometry. The equivalent geometry consists of an axial radioactive point source with respect to an arbitrary elliptical surface that lies between the radioactive point source and the circular surface of the detector. This expression was extended to include coaxial radioactive circular disk source. The results were compared with a number of published data to explain how significant this work is in the efficiency calibration procedure for the γ-ray detection systems, especially in case of using isotropic radiating γ-ray sources in the form of point and disk shapes.

• Journal of Korea Water Resources Association
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• v.37 no.11
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• pp.897-913
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• 2004

There has been continuous efforts to manage the water resources for the required water quality criterion at river channel in Korea. However, we could not obtain the partial improvement only for the point source pollutant such as, wastewater from urban and industrial site through the water quality management. Therefore, it is strongly needed that the Best Management Practice(BMP) throughout the river basin for water quality management including non-point source pollutant loads. This problem should be resolved by recognizing the non-point source pollutant loads from upstream river basin to the outlet depends on the land use and soil type characteristic of the river basin using the computer simulation by distributed parameter model based on the detailed investigation and the application of Geographic Information System(GIS). Used in this study, Annualized Agricultural Non-Point Source Pollution (AnnAGNPS) model is a tool suitable for long term evaluation of the effects of BMPs and can be used for un gauged watershed simulation of runoff and sediment yield. Now applications of model are in progress. So we just describe the limited result. However If well have done modeling and have investigated of propriety of model, well achieve our final goal of this study.