• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.135-147
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• 2018

In order to investigate the runoff characteristics of nonpoint source pollutants in the Lake Doam watershed, water quality and flow rate were monitored for 38-rainfall events from 2009 to 2016. The EMC values of SS, COD, TN and TP were in the range of 33~2,169, 3.5~56.9, 0.09~7.65 and $0.06{\sim}2.21mg\;L^{-1}$, respectively. As a result of analyzing the effect of rainfall factor on the nonpoint source pollutant load, EMCs of SS, COD and TP showed a statistically significant correlation with rainfall (RA) (p<0.01) and SS showed highly significant correlation with maximum rainfall intensity (MRI, R=0.48). The load ranges of SS, COD, TN and TP were 10.4~11,984.6, 1.1~724.4, 0.6~51.6 and $0.03{\sim}22.85ton\;event^{-1}$, respectively, showing large variation depending on the characteristics of rainfall events. The effect of rainfall on the load was analyzed. SS, COD and TP showed a positive correlation, but TN did not show any significant correlation. The annual load of SS was the highest with $88,645tons\;year^{-1}$ in 2011 when rainfall was the highest with 1,669 mm. The result of impact analysis of nonpoint source pollution reduction project and land-use change on runoff load showed that pollutant load significantly reduced from 2009 to 2014 but SS and TP loads were increased from 2014 to 2016 due to increase in construction area. Therefore, we suggested that nonpoint source pollution abatement plan should be continued to reduce the soil loss and pollutants during rainfall, and countermeasures to reduce nonpoint source pollution due to construction need to be established.

• Journal of Korea Water Resources Association
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• v.48 no.9
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• pp.695-709
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• 2015

The inflow of nonpoint pollution sources due to sustainable development and urbanization is gradually increasing and causes a diversity of water pollution. There are lots of difficulties to find a solution as the problems related to variation of hydrological and natural phenomenon. A differentiated method to estimate the nonpoint pollution sources has been proposed using rainfall and characteristics of urbanization and observed data from sewage treatment districts in the study. The types of nonpoint pollution sources on an assumption of combined sewer system have been classified as three types which are inflow of rainfall, bypass of sewage treatments, and combined sewer overflows from a river. Three types for estimation of nonpoint pollution sources applied more accurately to generate a amount of nonpoint pollution loads. This study is expecting a wide application for effective water resource management on TMDL (total maximum delivery load) unit watershed and sewage treatment districts.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.220-225
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• 2009

This study evaluates the water quality of the river near the alpine farmland in the upper Naerin stream, which is a typical stream of the upper Bukhan River with muddy water generation, by the flow examination, it aims to estimate the characteristics of nonpoint sources flowing out from the investigated area and figure out effective methods to reduce them. According to the result of water quality examination, the average BOD of the area not affected by the cultivated land among the areas of the upper Naerin River was 0.47mg/l, and total phosphorous was 0.007mg/l; thus, it maintained the cleanliness level of Ia. The average BOD of the area with the alpine farmland was 0.52mg/l, which was similar to the one of the non-cultivated land. But total phosphorous concentration was 0.023mg/l, which was more than three times higher than the area belonging to level II due to the effect of fertilizer ingredients discharged from the cultivated land. About the loadings of the investigated area generated from each of the pollution sources, BOD was 878.5kg/day and total phosphorous was 79.7kg/day. Moreover, for the load density, BOD was $2.22kg/day.km^2$ and total phosphorous was shown as $0.20kg/day.km^2$. Regarding the rates generated from nonpoint sources like land among the loadings per pollution sources, BOD was 54%, total nitrogen was 91%, and total phosphorous was 73.4%. Therefore, it was shown that most of the nutrients were produced from the nonpoint sources. The level of BOD runoff loading in the Jaun River area, where nonpoint sources were mainly generated, was 37.1kg/day and total phosphorous was 1.33kg/day. The flow rates to the generated amount were estimated as 10.5% and 4.7% each.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.342-349
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• 2016

Andong belongs to the Nakdong River Basin, Nakdong River is flowing through the city, including Andong dam and Imha dam. The runoff due to provincial transfer and impervious area has been increasing by urbanization increases and nonpoint source loads. In this study, we evaluate the runoff and nonpoint pollution loads in accordance with the development targeted at selected urban water cycle leading to Andong city. Andong city leading to the water cycle plan to evaluate the directly runoff and BOD, T-N and T-P nonpoint pollutant loads using the CN into account the temporal and spatial changes. Evaluation, direct runoff per year is 10.41 % if the green roof and a water permeable pavement replacement, water cycle parks and streets compositions, City impermeable layer improvements to be business including four kinds of scenario is applied to both the development and the BOD non-point pollutant loads 20.56%, T-N 9.55% and T-P pollution and nonpoint loads was investigated to be reduced 14.29%. Four kinds of low lapse rate of the development scenario of the highest thing urban impervious surface was investigated by improving business development prior year annual direct runoff is 6.25 %, BOD nonpoint pollution loads are 11.84%, T-N nonpoint pollution loads are 4.46 % and T-P was investigated by reducing pollutant loads to be 10.20%.

• Spatial Information Research
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• v.20 no.5
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• pp.25-35
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• 2012

This study compared the influence of water quality according to the data sources of spatial information. Firstly, land cover map was constructed through image classification of Daecheong-dam basin and the accuracy of image classification from satellite image showed high as 88.76% in comparison with the large-scaled land cover map in Ministry of Environment, to calculate Event Mean Concentration (EMC) by land cover that impact on the evaluation of nonpoint source pollutant loads. Also curve number and direct runoff were calculated by spatial overlay with soil map and land cover map from image classification. And Seokcheon and Daecheong-Dam basin showed high in the analysis of curve number and direct runoff. Samgacheon-Joint and Sokcheon-Downstream basin showed high in the nonpoint source pollutant loads of BOD from direct runoff and EMC. And Samgacheon-Joint and Bonghwangcheon- Downstream basin showed high in the nonpoint source pollutant loads of TN and TP. Nonpoint source pollutant loads from image classification were compared with those by the land cover map from Ministry of Environment to present the effectivity of nonpoint source pollutant loads from satellite image. And Daecheong-Dam Upstream basin showed high as 10.64%, 11.70% and 20.00% respectively in the errors of nonpoint source pollutant loads of BOD, TN, and TP. Therefore, it is desirable that spatial information including with paddy and dry field is applied to the evaluation of nonpoint source pollutant loads in order to simulate water quality of basin effectively.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.05a
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• pp.30-30
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• 2004

• Journal of Environmental Impact Assessment
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• v.23 no.5
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• pp.393-405
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• 2014

In this study, the nonpoint sources were evaluated by calculating the Nadonggang basin regional water quality and nonpoint source pollution load discharged. And were selected the banks of first administration based on the results and the direction of the next administration. As a results of estimating the water quality about BOD concentration in the mid influence area in the Nakdonggang basin, it was founded that 10 sites for 'Ia' water quality level, 6 sites for 'lb' water quality level, 5 sites for 'II' water quality level, 1 sites for 'I' water quality level. The estimation of COD concentration in the mid influence area, It showed that 9 sites for 'Ib' water quality level, 6 sites for 'II' water quality level, 6 sites for 'III' water quality level, 1 site for 'IV' water quality level. The assessment of water quality made Mid influence area of Gumhogang, Nakdong Goryung, Nakdong Milyang and Namgang selected as the mid influence area of high pollution. And delivery loads of nonpoint sources were calculated for mid influence area in Nakdonggang basin(max delivery load : 17,706.7 kg/day for Gumhogang influence area). As the result of calculating NPS(nonpoint sources) delivery load and water quality at influence area in Nakdonggang basin, Gumhogang influence area was selected as an area for management priority among nonpoint sources.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.2
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• pp.61-74
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• 2007

A mathematical modeling program called Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency (EPA) was applied to Hwaseong watershed. It was run under BASINS (Better Assessment Science for Integrating Point and Nonpoint Sources) program, and the model was validated using monitoring data of $2002{\sim}2005$. The model efficiency of runoff ranged from good to fair in comparison between simulated and observed data, while it was from very good to poor in the water quality parameters. But its reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The nonpoint source (NPS) loading for T-N and T-P during the monsoon rainy season (June to September) was about 80% of total NPS loading, and runoff volume was also in a similar range. However, NPS loading for BOD ($55{\sim}60%$) didn't depend on rainfall because BOD was mostly discharged from point source (more than 70%). And water quality was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. BASINS/HSPF was applied to the Hwaseong watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and nonpoint sources in watershed scale.

• Environmental Engineering Research
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• v.16 no.2
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• pp.61-67
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• 2011

The water quality from nonpoint source run off results from different land use types has been studied. The construction of a buffer strip is one method of nonpoint source pollutant control. The Soil and Water Assessment Tool (SWAT) model has been applied to estimate the pollutant removal through the buffer strip. When the non-business land has been changed into grass to form a buffer-strip, the change of land use effects the results of the model according to measures of the water quality. The data from a water level station within the watershed in the years 2006 and 2007 was used for calibration and validation of the model. Under the rainfall conditions in 2007, the removal rates of SS, BOD, TN, TP were 11.5%, 9.5%, 1.2%, and 4.5%, respectively. During the rainy days, the removal rates at the buffer strip were 92.3% of SS, 91.2% of BOD, 82.4% of TN, and 83.5% of TP. The pollutants from nonpoint sources were effectively removed by over 80% as they passed through the buffer strips. Rainfall resulted in soil erosion, which led to an increase in the SS concentration, therefore, the construction of buffer strips protected the streams from SS inflows. Since TN concentrations are affected by the inflows of ground water and the N concentration of the rainfall, the removal rate of TN was relatively lower than for the other pollutants.

• KCID journal
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• v.13 no.2
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• pp.283-292
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• 2006

The characteristics of nonpoint source pollutant loads in upstream of Nakdong River were studied through analysis of pollutant loads of 10 sub-watersheds divided based on administrative district. The discharge and pollutant concentration of each sub-watershed were collected from Nakdong-River Water Research Institute and Daegu Regional Environmental office, respectively. Pollution items analysed in this study were BOD, T-N and T-P. The delivery loads of the nonpoint source pollutions of each sub-watershed were calculated after analysing the concentration of the pollution of each site. Several points were found from the results. Firstly, in general, city areas including Sangju, Andong showed higher degree of nonpoint pollution than country areas including Cheongsong, Yeongyang. The sub-watersheds located upstream side, such as Yeongju, Bonghwa, Necessarily show better water quality than the sub-watersheds located downstream side, such as Mungyeong, Uiseong. This result indicates that a given pollution condition within the watershed can be more sensitive than location factor to the level of water quality. Secondly, the delivery load and area of watershed were not necessarily correlated in the sense of water quality, while the discharge was shown to be highly correlated to the delively load of pollution. Lastly, sewage and waste caused from population and livestock, as well as landuse factor, were found to significantly contribute to the water pollution. Alternative solutions for controlling pollution source, therefore, should be provided to meet target levels of water quality in these regions.