• 산업기술연구
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• 제25권B호
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• pp.37-46
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• 2005

From 2000 to 2004, the research was carried out at Naerin-cheon and Inbook-cheon, the upper streams of Soyang Lake, to study the relationship between precipitation and eutrophication-causing water pollutants, BOD, T-N and T-P. During the five years, the amount of flowing water was measured, and the water quantity was examined under different precipitation levels. From the observation, outflow patterns of the water pollutants and changes in the water quality factors at the time of rainfall were clarified. In addition, estimation of the unit load was made for each stream; for Naerin-cheon at the time of rainfall, we estimated BOD to be $1,112kg/km^2/year$, T-N to be $2,077kg/km^2/year$, and T-P to be $223kg/km^2/year$; for Inbook-cheon at the time of rainfall, we estimated BOD to be $1,229kg/km^2/year$, T-N to be $1,565kg/km^2/year$, and T-P to be $255kg/km^2/year$. For the time of no rainfall different estimation was made; for Naerin-cheon, we estimated BOD to be $2,403g/km^2/day$, T-N to be $5,004g/km^2/day$, and T-P to be $53g/km^2/day$; and for Inbook-cheon, we estimated BOD to be $1,550g/km^2/day$, T-N to be $2,283g/km^2/day$, and T-P to be $42g/km^2/day$.

• 상하수도학회지
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• 제9권4호
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• pp.73-86
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• 1995

The propriety of the numerical model application was examined on Paldang resevoir and its inflow tributaries located in the center of the Korean peninsula and the long term water quality forecast of the oxygen profile was carried out in this syduy. The input data of the model was the capacity of the reservoir, catchment area, percolation, diffusion rate, vertical mixing rate, dissolution rate from the bottom of the reservoir, outflow of the resevoir, water quality measurement and meteorology data of the drainage basin, and the output result was the annual estimation value of the dissolved oxygen concentration and the biochemical oxygen demand. The modeling method is based on the measured or calculated boundary condition dividing the water area into several blocks from the macorscopic aspect and considering the mass balance in these blocks. As the result of the water quality forecast, it was expected that the water quality in Northern Han River and Paldang reservoir would maintain the recent level, but that the water quality in the Southern Han River and its inflow tributary would worsen below the grade 4 of the life environmental standard from around 2000 owing to the decrease of DO concentration and the increase of BOD concentration.

• 한국환경보건학회지
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• 제28권2호
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• pp.149-160
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• 2002

Analysis of benthic macroinvertebrate community structure and biological estimation of water quality by the benthic macroinvertebrates from the Mt. Myungji(1267m), Mt. Kalbong(840m), Mt. Daegeum(704m) and Mt. Jubal(489m) region of Gapyung-gun, Kyunggi-do were investigated from April to November, 2001. Total taxa of benthic macroinvertebrates were 105 species, 38 families, 13 orders, 5 classes in 4 phyla. Aquatic insects were 33 species in ephemeroptera, 5 species in odonata, 13 species in plecoptera, 2 species in hemiptera, 1 species in megaloptera, 27 species in trichoptera, 3 species in coleoptera and 13 species in diptera, respectively. Non-insects were 1 species in platyhelminthes, 5 species in gastropoda, 1 species in oligochaeta, 1 species in crustacea, respectively. Ephemeroptera, trichoptera and plecoptera as indicators in clean water were very abundantly. Occurrence species at each survey area was 67 species at Mt. Myungji and 69 species at Mt. Kalbong, 48 species at Mt. Daege.um and 47 species at Mt. Jubal, respectively. Mean species diversity indices at Mt. Myungji, Mt. Kalbong, Mt. Daegeum and Mt. Jubal were 3.30, 3.33, 2.59 and 3.43, respectively. According to the saprobic system based on the species diversity indices of benthic macroinvertebrates, Mt. Myungji, Mt. Kalbong and Mt. Jubal are determined as Limnosaprobic area, respectively, but Mt. Daegeum is determined as $\beta$-mesosaprobic area.

• 한국물환경학회지
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• 제32권2호
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• pp.149-162
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• 2016

In recent years, there has been demand for precise estimations of pollutant loads on nationwide scale for the development of appropriate site specific (watershed specific) policies to reduce the negative impact of pollutant loads. River flow data and water quality data that were previously collected by various research institutes and universities for specific research purposes for a limited period was utilized in this study. However, only TMDL 8-day interval flow and water quality data were available in national scale. Three watersheds were selected and pollutant loads were calculated by two methods i.e., Numeric Integration (NI) method and Soil and Water Assessment Tool (SWAT). Subsequently, the results were compared to determine the appropriate method for monitoring nonpoint source networks nationwide. The SWAT model was calibrated and its estimated daily flow data were used in the NI method with estimated sediment data for 8-day monitoring data for three watersheds. The results indicated that the quantity of pollutant loads estimated with the NI and SWAT are different to some degrees especially during the summer season for all the three study watersheds. Thus, more frequent sampling of water quality is needed for nonpoint source pollutant estimation.

• 한국물환경학회지
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• 제37권3호
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• pp.175-189
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• 2021

In this study, 48 streams in the Sapgyo Watershed were selected, and the Load Duration Curves (LDC) were drawn up for each stream using water quality and flow monitoring over the last three years (2018-2020), and it was evaluated whether the target water quality was achieved for each flow section. As a result of evaluating whether or not the target water quality exceeded according to the LDC, it was found that 22 rivers exceeded the target water quality. Five rivers exceeded the target water quality due to point pollutant sources, 13 rivers exceeded the target water quality due to non-point pollutant sources, and 4 rivers exceeded the target water quality due to both point and non-point pollutant sources. Among the rivers that exceeded the target water quality due to point pollutant sources, which included domestic sewage of the untreated population, there is a need to reduce the influx of polluted loads by the untreated population. The use of eco-friendly fertilizers is recommended for rivers with a relatively high farmland ratio among rivers exceeding the target water quality due to non-point pollutant sources, and installation of boiling point reduction facilities that can reduce the amount of polluted load introduced during rainfall or manage water shores. In rivers with a large number of livestock breeding heads, the livestock houses located in these rivers need to be preferentially transferred to livestock manure treatment plants. Due to the high ratio of land area because of urbanization, initial rainwater treatment facilities are required to reduce the amount of pollutant load flowing into the river through the impermeable layer during rainfall.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1181-1181
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• 2005

• 한국물환경학회지
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• 제25권2호
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• pp.212-220
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• 2009

In many studies, the Numeric Integration (NI) method has been widely used to calculate pollutant loads from the watershed because it is easy to apply. However, there have been many needs for more accurate pollutant loads estimation method with the restricted number of water quality samples. However, the ESTIMATOR model does not allow the users to define the regression model to explain the measured flow and water quality relationship, indicating the ESTIMATOR model is not flexible. The LOADEST model allows the user to choose the model type from 11 predefined general forms of regression equations. Annual loads of T-N and T-P with the LOADEST model were 0.70 times and 0.84 times of those by NI method, respectively. The coefficient of determination ($R^2$) of the LOADEST regression for the T-N and T-P were 0.92 and 0.72, respectively. This indicates that the load estimation regression model with the LOADEST for the study watershed explains the relationship between the observed flow and water quality data well reasonably well. Based on these findings, we suggest that the LOADEST model estimated regression equation could be used to estimate pollutant loads using the measured flow data for the study watershed.

• 한국해안해양공학회지
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• 제19권1호
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• pp.45-56
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• 2007

수량 및 수질자료, 특히 수질자료가 없는 구간에서의 직접계산에 의한 오염부하 산정은 불가능하기 때문에 적절한 방법을 이용하여 결측구간의 자료를 보완(data filling)하여 계산하는 추정과정을 필요로 한다. 본 연구에서는 수질자료가 없는 구간, 즉 수질 결측구간에서 오염부하량을 산정하기 위한 다양한 농도 추정방법을 제시하고, 제시된 방법을 이용하여 추정된 농도변화 양상 분석 및 오염부하 변동양상을 비교 분석하여 보다 효과적이고, 효율적인 추정방법을 최종 제안하였다. 또한, 오염부하에 영향을 미치는 수량 및 수질인자의 상대적인 중요성과 연안 하천의 오염부하 특성을 구분할 수 있는 영향인자를 제시하였다. 수질자료 결측구간의 다양한 농도 추정방법을 이용하여 한강하구의 오염부하를 산정한 결과, 결측구간을 제외하고 추정한 오염부하는 매우 낮은 비현실적인 결과를 제시하였으며, 가용자료의 변동성을 고려한 선형내삽법이 가장 적합한 방법으로 파악되었다. 또한, 한강하구의 오염부하양상은 수량주도형으로 판단되었으며, 결측구간의 농도추정은 불가피한 과정으로 적절한 추정방법을 이용하는 것이 보다 바람직한 것으로 파악되었다.

• 한국물환경학회지
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• 제31권6호
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• pp.653-664
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• 2015

TPLMS (Total water pollutant load management system) that is the most powerful water-quality protection program have been implemented since 2004. In the implementation of TPLMS, target water-quality and permissible discharged load from each unit watershed can be decided by water-quality modeling. And NPS (Non-point sources) discharge coefficients associated with certain (standard) flow are used on estimation of input data for model. National Institute of Environmental Research (NIER) recommend NPS discharge coefficients as 0.15 (Q₂₇₅) and 0.50 (Q₁₈₅) in common for whole watershed in Korea. But, uniform coefficient is difficult to reflect various NPS characteristics of individual watershed. Monthly NPS discharge coefficients were predicted and estimated using surface flow and water-quality from HSPF watershed model in this study. Those coefficients were plotted in flow duration curve of study area (Palger stream and Geumho C watershed) with monthly average flow. Linear regression analysis was performed about NPS discharge coefficients of BOD, T-N and T-P associated with flow, and R² of regression were distributed in 0.893~0.930 (Palger stream) and 0.939~0.959 (Geumho C). NPS Discharge coefficient through regression can be estimated flexibly according to flow, and be considered characteristics of watershed with watershed model.

• 상하수도학회지
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• 제29권3호
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• pp.347-357
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• 2015

Baswflow is defined as short term discharge through groundwater caused by rainfall events. Impacts of baseflow is significant on water quality especially where pervious agricultural watershed as groundwater is more vulnerable to the contamination. In this study, the Cheongmicheon watershed was subjected to study to assess the impacts of baseflow on surface water quality, where more than 90% of pollutant load is originated from the livestock raising area, and very high probability of surface water contamination due to the baseflow. To estimate nutrient loading cased by baseflow, NI (Numerical Integration) model and LOADEST (LOADing ESTimation) model were used.