• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.311-321
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• 2009

Long-Term Hydrologic Impact Assessment (L-THIA) was modified to improve runoff and pollutant load prediction for Korean watersheds with changes in land use classification and event mean concentration produced from observed data in Korea. The L-THIA model was linked with SCE-UA, which is one of the global optimization techniques, to automatically calibrate direct runoff. Modified L-THIA model was applied to Gumho River Basins to analyze spatial distribution of nonpoint source pollution. The results of model calibration during 1991~2000 and validation during 1981~1990 for direct runoff represented high model efficiency of 0.76 for calibration and 0.86 for validation. As a results of spatial analysis of nonpoint source pollution, the BOD was mainly loaded from urban area but SS, TN, and TP from agricultural area which is mainly located along the stream. Modified L-THIA model improve its accuracy with minimum imput data and application efforts. From this study, we can find out the L-THIA model is very useful tool to predict direct runoff and pollutant loads from the watershed and spatial analysis of nonpoint source pollution.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.102-111
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• 2009

Turbid storm runoff from intensive highland agriculture area has emerged as the major problem of water quality deterioration in the upstream region of the Han River. High slope of the upland combined with high rate of fertilization and intensive plowing causes high rate of soil erosion, and subsequently high suspended sediment and phosphorus content in the runoff water. The variations of water quality during rain spells were surveyed for two years (2005 and 2006) in the Jawoon Stream that is one of hot spots of intensive horticulture discharging turbid storm runoff. SS and TP showed large increase according to the increase of flow rate, whereas TN and BOD showed less fluctuations. Mean EMCs of SS and TP measured for nine rain events were as high as $207mgSS{\cdot}L^{-1}$ and $0.27mgP{\cdot}L^{-1}$, respectively. The export coefficient of SS and TP per area of cultivated field were calculated as $11,912kgSS{\cdot}yr^{-1}{\cdot}km^{-2}$ and $785kgP{\cdot}yr^{-1}{\cdot}km^{-2}$, repectively, which are significantly higher than reports of other area. It can be concluded that SS and TP in the runoffs were high enough to impose major threat to aquatic habitats, and the highland agriculture should be the main target of water quality management or habitat conservation in the study area.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.97-106
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• 2013

The temporal and spatial variations of water quality in a stratified reservoir are fully dependent on the characteristics of inflow loading from its watershed and the transport regimes of pollutants after entering the reservoir. Because of the meteorological and hydrological conditions in Korea, the pollutants loading to reservoirs are mostly occur during rainfall events. Therefore it is important to understand the characteristics of pollutants loading from upstream rivers and their spatial propagation through the stratified reservoir during the rainfall events. The objectives of this study were to characterize the water quality variations in upstream rivers of Imha Reservoir during a rainfall event, and the transport and spatial variations of pollutants in the reservoir through extensive field monitoring and laboratory analysis. The results showed that the event mean concentration (EMC) of SS, BOD, $COD_{Mn}$, T-N, T-P, $PO_4-P$ are 8.6 ~ 362.1, 2.5 ~ 5.1, 1.5 ~ 5.1, 1.1 ~ 1.9, 8.3 ~ 57.1, 5.6 ~ 25.7 times greater than the mean concentrations of these parameters during non-rainfall period. The turbidity and SS data showed good linear correlations, but the relationships between flow and SS showed large variations because of hysteresis effect during rising and falling periods of the flood. The ratio of POC to TOC were 12.6 ~ 14.7% during the non-rainfall periods, but increased up to 28.2 ~ 41.7% during the flood event. The turbid flood flow formed underflow and interflow after entering the reservoir, and delivered a great amount of non-point pollutants such as labile and refractory organic matters and nutrients to the metalimnion layer of reservoir, which is just above the thermocline. Spatially, the lateral variations of most water quality parameters were marginal but the vertical variations were significant.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.888-888
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• 2012

본 연구는 3년(2008~2011년)간의 연구기간동안 저탄장에서 발생하는 유량과 수질농도를 분석하여 저탄장의 비점오염 유출특성을 파악하고자 하였다. 연구지점은 강원도 태백시에 위치한 가행 광산으로써 광산작업으로 인해 생산되는 비축탄(석탄과 광재)을 저장하는 대규모 저탄시설이다. 저탄장에는 강우로 인해 발생하는 강우유출수의 오염물질 배출량을 줄이기 위해 콘크리트 배수로와 침사지 시설이 설치되어 있다. 침사지를 거쳐 하천으로 유입되기 전에 강우유출수의 모니터링을 위해 모니터링 시설(유량계, 자동수질시료채취기, 강우량계)을 설치하여 유량과 농도를 측정하였다. 또한 정확한 강우량 측정을 위해 자기우량계를 설치하였다. 연구결과 강우에 의해 유출이 발생한 최저 강우량은 6.0 mm 인 것으로 나타났으며, 강우사상의 강우량은 6.0~248.4 mm의 범위로 나타났다. 이때 평균 강우강도는 0.6~13.1 mm/hr 인 것으로 나타났으며, 강우에 발생한 강우유출수의 유출률은 0.02~0.40으로 나타났다. 저탄장의 경우 저탄장의 표면을 비닐 캔버스로 덮어두기 때문에 불투수층이 많아 6.0 mm 정도의 적은양의 강우가 발생해도 유출이 발생하는 것으로 나타났다. 각 강우사상의 EMC 농도는 SS 6.5~712.3 mg/L, $COD_{Cr}$ 11.6~263.9 mg/L, $COD_{Mn}$ 3.4~106.8 mg/L, $BOD_5$ 1.0~56.0 mg/L, TN 0.145~5.600 mg/L, TP 0.101~2.526 mg/L, DOC 0.6~22.0 mg/L로 나타났다. 저탄장에서 측정된 수질농도는 기존 가행 광산에 관한 연구에 비해 SS 농도가 낮게 산정 되었으며, 이는 저탄장에 설치되어 있는 침사지 시설의 영향인 것으로 판단된다. 본 연구의 결과는 저탄장에서 발생하는 비점오염원의 유출특성을 파악하고, 모델링이나 환경정책에 필요한 기초자료로 활용할 수 있을 것으로 판단된다. 그러나 강우량, 면적, 피복율 또는 침사지 시설 등의 영향에 대한 추가적인 모니터링을 통한 다각적인 분석의 연구가 진행되어야 할 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3270-3278
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• 2014

Many researches has been conducted as extreme rainfall in hydrology and extreme rainfall analysis is not proper for determination of CSOs treatment capacity. In this study, runoff is calculated by tranformation from rainfall to runoff according to Interevent Time Definition. The capacity of sewage treatment plant is designed by 3 times of DWF(Dry Weather Flow) and the efficiency of present sewage treatment plant is very low becauseat at present. Also, The sewage treatment plant can not control CSOs. In this research, the pollution load is calculated by EMC(Event Mean Concentration) and pollution concetration of total runoff is a standard deciding suitablility of present sewage treatment plant. Finally, CSOs treatment capacity is determinated considering pollution load.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.13-17
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• 2019

This study was conducted to analyse the application of pollutant build-up model on various urban landuses and to characterize pollutant build-up on urban areas as a source of stormwater runoff pollution. The monitored data from impervious surfaces in urban areas such as commercial (8 sites), industrial (10 sites), road (8 sites), residential (10 sites), recreational (5 sites) from 2008 to 2016 were used for the analysis of pollutant build-up model. Based on the results, the average runoff coefficients vary from 0.35 to 0.61. In all landuses except recreational landuse, the runoff coefficient is 0.5 or more, which is the highest in the commercial area. Commercial landuse where pollutants occur at the highest EMC in all landuse, and it is considered that NPS management is necessary compared with other landuses. The maximum build-up load for organic matter (BOD) was highest in the commercial area ($4.59g/m^2$), and for particular matter (TSS) in the road area ($5.90g/m^2$) while for nutrient (TN and TP) in the residential area ($0.40g/m^2$, $0.14g/m^2$). The rate constants ranged from 0.1 to 1.3 1/day depending on landuse and pollutant parameters, which means that pollutant accumulation occurs between 1 and 10 days during dry day. It is clear that these build-up curves can generally be classified based on landuse. Antecedent dry day (ADD) is a suitable and reasonable variable for developing pollutant build-up functions. The pollutant build-up curves for different landuse shows that these build-up curves can be generally categorized based on landuse.

• Journal of Korean Society on Water Environment
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• v.35 no.1
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• pp.9-18
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• 2019

Recently, it was realized that a significant portion of pollution from urban areas originates from non-point sources such as construction sites, washoff from impervious surfaces, and sewage input from unsewered areas and combined sewer overflows. Especially, Urban stormwater runoff is one of the most extensive cause of the deterioration of the water quality in streams located in urban area. The objective of this study was to investigate runoff characteristics of non-point pollutants source at the urban area in the Suyeong River. Water quality variations were investigated at two points of Suyeong River during a period of 10 rainfall events. Concentration difference of non-point pollution source appeared big by precedent number of days of no rainfall. In addition, Event mean Concentration (EMCs) that well represents runoff characteristics of storm water during rainfall, was calculated, and runoff pollutants loading was also examined. The probability distribution of EMCs of BOD, COD, TOC, T-N, T-P, and TSS were analyzed and the mean values of observed EMC and the median values of estimated EMCs compared through probability distribution. Other objectives of this study were the characterization of discharge from non-point source, the analysis of the pollutant loads and an establishment of a management plan for non-point source of Suyeong River. Also, It was established that the most important thing for the administration of non-point pollution source is to come up with the solution for the reduction of effluent at the beginning.