• Journal of Environmental Impact Assessment
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• v.26 no.1
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• pp.68-77
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• 2017

In order to estimate the non-point pollution loads from each watersheds among 209 watersheds, the calibration and validation of HSPF model were carried out based on 2012 in 2013 years. In the case of flow rate, R2 of calibration and validation were 0.71~0.93 and 0.71~0.79, which were relatively good values. With the respect to calibration of water quality, % differences between measured and simulated values were 0.4 ~ 9.7 of DO, BOD 0.5 ~ 30.2% and TN 1.9~28.6% except for Hwhangkang B site. In case of validation, DO was 0.2 ~ 13.7%, BOD 1.3~23% and TN 0.5~24.3% excluding Hwhangkang B. However, since the concentration of TP was very small compared with other items, the range of difference was large as 0.8~55.3%. level. As the result of calculating annual accumulative BOD loads for each watershed, it was found that RCH 123 (Uryeong, Gyeongsangnamdo), RCH 121 (Jinju, Gyeongsangnamdo) and RCH 92 (Daegu) were the high ranked. The unit watersheds including various landuse type susch as forest and agricultural sites in mainstream areas have a higher BOD nonpoint pollution load than those in dam regions. However, the results of the annual cumulative loading of the basins for nutrients did not appear to be consistent with the BOD annual cumulative loading ranks. Other factors that represent watershed characteristics such as landslope and soiltypes, including landuse pattern, have been found to be closely related to nonpoint pollutant loads.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.8
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• pp.480-491
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• 2015

In this study, methods using LDC (Load Duration Curve) and watershed model were suggested to develope management targets and evaluate target achievement for non-point source pollution management considering watershed and runoff characteristics and possibility for achievement of target. These methods were applied for Saemangeum watershed which was designated as nonpoint source pollution management area recently. Flow duration interval of 5 to 40% was selected as flow range for management considering runoff characteristics and TP was selected as indicator for management. Management targets were developed based on scenarios for non-point source pollutant reduction of management priority areas using LDC method and HSPF model which was calibrated using 4 years data (2009~2012). In the scenario of LID, road sweeping and 50% reduction in CSOs and untreated sewage at Jeonju A20 and 30% reduction in fertilizer and 50% in livestock NPS at Mankyung C03, Dongjin A14 and KobuA14, management targets for Mangyung bridge, Dongjin bridge, Jeonju stream and Gunpo bridge were developed as TP 0.38, 0.18, 0.64 and 0.16 mg/L respectively. When TP loads at the target stations were assumed to have been reduced by a certain percentage (10%), management targets for those target stations were developed as TP 0.35, 0.17, 0.60 and 0.15 mg/L respectively. The result of this study is expected to be used as reference material for management master plan, implementation plan and implementation assessment for non-point source management area.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.966-970
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• 2009

경기도 용인시, 오산시와 화성시 지역의 농업용수와 공업용수의 공급원으로 이용되고 있는 신갈호는 현재 유입하천으로부터 미처리된 도시하수, 공장 폐수, 축산 폐수 등의 점오염원 및 도시 지역 불투수층에 쌓여있는 오염물질인 비점오염원이 무분별하게 유입되어 수질이 매우 악화되어 용수로의 사용이 어려운 지경에 달하였으며, 자연정화능력도 감소하는 등 심각하게 오염되었다. 또한 최근에는 신갈호 유역의 개발에 따른 토지이용 변화로 신갈호 유역의 총오염부하량이 증가하고 있는 실정이다. 따라서 본 연구에서는 현재 날로 심각해지는 신갈호 유입하천의 비점오염원 조사를 통해 신갈호 및 유입하천의 기초데이터의 확충 및 현황 파악을 하고자 하였다. 본 연구에서는 강우 시 신갈호로 유입되는 3개의 유입지천인 신갈천(SG), 지곡천(JK), 공세천(KS)에서 비점오염부하량을 산정함으로써 강우 시 호소로 유입되는 총오염부하량 및 비점오부하량의 비율을 알아보고자 하였다. 강우사상에 따른 총 오염물질 부하량은 EMC 농도를 구한 후 총 유출유량을 곱하고 총 강우지속시간을 곱하여 산정하였다. 조사결과 강우기에 있어서 거의 모든 항목의 농도는 평수기보다 매우 높은 수치를 나타냈다. 특히 SS 농도는 토사의 하천유입으로 인해 다른인자에 비해 큰 변동폭을 나타내었으며, COD와 T-P는 토양입자에 흡착되어 함께 이동하기 때문에 SS와 밀접한 관계를 가졌다. 강우시의 각 유입하천별 오염부하 기여율은 SG의 경우 SS 74.1%, BOD 64.4%, COD 65.7%, T-N 63.8%, T-P 73.8%를 나타내었다. JK의 경우 SS 25.4%, BOD 31.5%, COD 30.5%, T-N 32.5%, T-P 24.2% 였고, KS의 경우 SS 0.5%, BOD 4.1%, COD 3.8%, T-N 3.7%, T-P 2.0%를 나타내었다. 강우시의 각 유입하천별 오염부하 기여율을 평수기때의 오염부하 기여율과 비교하였다. 비교결과 SS의 경우는 SG가 강우시에 74%, 평수기에 83%, BOD의 경우는 강우시 64%, 평수기 80%, T-N은 강우시 64%, 평수기에 84%, T-P의 경우는 강우시 74%, 평수기에 82%로 모든 항목에서 평수기에 신갈천이 신갈호의 오염부하에 미치는 영향이 큰 것으로 나타났는데, 이는 강우시 지곡천의 기여율이 평수기 보다 상대적으로 높아지기 때문인 것으로 판단된다.

• Journal of Korea Water Resources Association
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• v.37 no.11
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• pp.959-967
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• 2004

The concentrations and loads of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) in wet deposition were investigated at Chungbuk National University in Cheongju, Chungbuk. Event based precipitation samples were collected during 1998 to 2003. The precipitation-weighted mean concentrations of pollutants were 0.60 mg/L for TN, 0.014 mg/L for TP, and 4.8 mg/L for COD, which were smaller than its arithmetic mean concentrations by 26% for TN, 18% for TP, and 14% for COD. The concentrations of TN, TP, and COD significantly decreased with precipitation. Mean concentrations of pollutants in spring (March-May) were higher than in other seasons likely due to dust caused by wind erosion and sand-dust storms, pollen etc. Significant relationships were determined between TN and TP, and TN and COD. Annual loads of wet deposition averaged 7.9 kg/ha$\cdot$yr for TN, 0.19 kg/ha$\cdot$yr for TP, and 63.9 kg/ha$\cdot$yr for COD, which are almost identical to the values of TN and TP but slightly higher than COD value reported in Japan.

• Journal of Korea Water Resources Association
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• v.36 no.4
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• pp.533-545
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• 2003

This study analyzed several storm events observed in the Seolma-chun basin to derive the characteristic velocity of GIUH (Geomophological Instantaneous Unit Hydrograph) as well as its variability. Especially, this study focused on the variation of characteristic velocity due to the change of rainfall characteristics. The IUH of the Seolma-chun basin was derived using the HEC-1, whose peak discharge and time were then compared with those of the GIUH to derive the characteristic velocities. The characteristics velocities were analyzed by comparing with the GcIUH (Geomorphoclimatic IUH) as well as the characteristics of rainfall. Results are summarized as follows. (1) The characteristic velocity of GIUH was estimated higher with higher variability than the GcIUH, but their trends were found similar (2) Total amount of effective rainfall (or, mean effective rainfall) well explains the characteristic velocity of GIUH. This could be assured by the regression analysis, whose coefficient of determination was estimated about 0.6. (3) The duration and the maximum intensity of rainfall were found not to affect significantly on the characteristic velocity of GIUH. The coefficients of determination were estimated less than 0.3 for all cases considered. (4) For the rainfall events used in this study, the characteristic velocities of GIUH were found to follow the Gaussian distribution with its mean and the standard deviation 0.402 m/s and 0.173 m/s, respectively. Most of the values are within the range of 0.4∼0.5 m/s, and its coefficient of variation was estimated to be 0.43, much less than that of the runoff itself (about 1.0).

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1253-1257
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• 2010

강원도 홍천군 내면에 위치한 비점오염 관리지역의 강우시 유출 특성을 파악하고, 비교하기위해 연구를 수행하였다. 2009년 6월부터 2009년 11월까지의 연구기간 중 강우량이 비교적 많은 7회의 강우사상에 대하여 단위면적당 유출량, 유량가중평균농도, 단위면적당 오염부하를 비교하며, 분석하였다. 강우사상별 단위면적당 총 유출량은 저감시설의 설치 유 무에 따라 명확한 경향이 나타나지 않았다. 자운천 유역의 SS, TP의 유량 가중평균농도는 각각 4.0~1440.4 mg/L와 0.024~0.267 mg/L의 범위로 나타났으며, 덕두원 유역의 SS, TP의 유량가중평균농도는 각각 6.2~1001.1 mg/L, 0.039~0.226 mg/L의 범위로 나타났다. 지령골 유역의 SS, TP의 유량가중평균농도는 각각 3.4~1050.6 mg/L, 0.08~0.342 mg/L의 범위로 조사되었다. 10차, 11차, 12차, 26차의 SS 항목에서는 비점오염 저감시설이 설치된 자운천과 덕두원 유역에 비해 다소 높은 것으로 나타났으며, TP는 대부분의 강우사상에서 지령골의 유량가중평균농도가 높았다. 자운천의 강우사상에 따른 SS의 단위면적당 오염부하는 0.24~1,397.85 kg/ha의 범위로 나타났으며, 덕두원과 지령골에서 산정된 SS의 단위면적당 오염부하는 각각 0.06~1,236.78 kg/ha와 0.29~894.81 kg/ha로서 8차와 9차 강우사상을 제외한 나머지 강우사상에서는 비점오염 저감시설이 설치되지 않은 지령골에서 더 많은 양이 발생하였다. TP의 경우 자운천과 덕두원 유역의 단위면적당 TP 오염부하는 각각 0.0006~0.33 kg/ha와 0.0005~0.21 kg/ha의 범위로 나타났으며, 지령골 유역의 강우사상에 따른 단위면적당 오염부하는 0.003~0.29 kg/ha의 범위로서 저감시설이 설치된 자운천과 덕두원 유역보다 높게 나타났다. 단위면적당 오염부하에 기초할 때, 비점오염 저감시설이 설치된 소유역에서 SS와 TP 항목에 대한 저감효과가 나타났다. 하지만 짧은 모니터링 기간과 자료의 부족으로 인해 비교 및 분석의 한계가 있다고 판단된다. 본 연구는 지속적인 모니터링으로 더 많은 자료가 확보될 때 비점오염 저감사업의 효과를 극대화시킬 수 있는 방안을 제시 할 수 있을 것으로 사료된다.

• Journal of Korea Water Resources Association
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• v.51 no.10
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• pp.917-927
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• 2018

Seven heavy metal concentrations (As, Cd, Cr, Cu, Ni, Pb, Zn) were continuously analyzed for twenty rainfall events in 2017~2018 in an urban basin. The overall and dynamic correlations between runoff characteristics and heavy metal concentrations were examined. The peak metal concentration generally appeared in the initial runoff but found to be delayed when the rainfall intensity was low. The rainfall duration had no relationship with either heavy metal concentrations or their total mass. Dynamics of heavy metal mass (load), with the exception of Cu and Zn, showed strong correlation with the 30 minute rainfall intensity (0.60~0.88) and runoff volume (0.74~0.89). While event mean concentration (EMC) showed positive correlation (0.54~0.73) with antecedent dry days (ADD), no significant relationship was found between runoff volume and pollutant concentration. This implies that the pollutants built up on the surface during dry days are washed off even with low rainfall energy. The dynamics of heavy metal and TSS concentrations showed good correlation (0.68~0.87). This result shows that the metals are transported along with solid particles as adsorbate in surface runoff. Regular street sweeping will reduce significant amount of heavy metal loads in urban surface runoff.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.283-296
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• 2014

The distribution of heavy metals in the stormwater runoffs from industrial sites around Shihwa Lake that implements the total pollutant load management system (TPLMS) was studied to characterize the temporal changes of metal concentrations and to assess the ecological risk in dissolved and particulate phases of the selected metals. The dissolved Co and Ni concentration demonstrated first flush and tended to decrease with increasing of the duration of rainfall. The intensity of precipitation was found to be the main controlling factor of particulate metals in the stromwater runoffs. The particulate concentration of Pb accounted for 97.2% so the particulate phase was its main form. Other metals followed the sequence: Pb>Cu>Cd>Co>Zn>Ni. The particulate-dissolved partitioning coefficient ($K_d$) indicated that the $K_d$ of Pb were bigger than that of other metals because the metal Pb in the stormwater runoffs is quickly removed into the particulate phase. In a single day rainfall event, total runoff fluxes for total metals as the sum of dissolved and particulate forms through only two sewer outlets were 2.21 kg for Co, 30.5 kg for Ni, 278.3 kg for Cu, 398.3 kg for Zn, 0.39 kg for Cd and 40.0 kg for Pb, respectively. Given the annual rainfall, the number of rain days and the basin area for total pollutant load management system (TPLMS) of Shihwa area, enormous amount of non-point metal pollutants were entered into Lake with any treatment. The dissolved metals (e.g., Ni, Cu and Zn) in the stormwater runoffs exceeded the acute water quality criteria. Additionally, all metals were significantly enriched in the particulate phase and exceeded the PEL criteria of sediment quality guidelines (SQGs). These results indicated that the heavy metals in the stormwater runoffs may pose a very high ecological risk to the coastal environments and ecosystem.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.296-304
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• 2011

This study was carried out to investigate the relation between water quality and structure of the aquatic ecosystem in the Lake Gachang from February to December in 2010. The annual mean COD (Chemical Oxygen Demand) in Lake Gachang was 3.5 mg $L^{-1}$, indicating, level II of environmental standards and the trophic state was mesotrophic. The seasonal succession of phytoplankton showed that Bacillariophyceae was mostly dominant species throughout the year except August. In case of zooplankton, rotifers dominate in the most seasons, but copepod (Nauplii) in August. The macrophyte plants showed diverse species composition consisted of 9 varieties, 77 species, 64 genera, 34 families and 24 orders. Surveyed species of macroinvertebrates were classified into 1 phyla, 2 classes, 4 orders, 7 families, 9 species. The macroinvertebrates showed FFG (Functional Feeding Groups) such as GC (Gathering-Collector) and SH (Shedder). A total of 42 species of fish was collected including $Zacco$ $koreanus$ and $Coreoperca$ $herzi$. In this study, we investigated environmental factors including pollutant source, load, water quality and distribution characteristics of biota such as phytoplankton, zooplankton, macrophyte plants, macroinvertebrates, fish.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.324-332
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• 2014

In order to reveal the long-term variations of water quality in Jinhae Bay, water qualities had been monitored at 9 survey stations of Jinhae Bay during 2000~2012. The surface and bottom waters concentrations of chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chlorophyll-a (Chl.-a) were higher at the survey stations of Masan Bay than the stations of other Bays. Especially, station 1 which is located at the inner area of Masan Bay had the highest values in the concentrations of COD, DIN, and Chl.-a because there were terrestrial pollutant sources near the station 1 and sea current had not well circulated in the inner area of Masan Bay. In factor analysis, the station 1 also had the highest factor values related to factors which increase organic matters and nutrients in surface and bottom waters of Masan Bay. However, the stations (st.5, st.6, st.7, st.8, and st.9) of other Bays had lower values of the factors. In time series analysis, the COD concentrations of the bottom waters at 8 stations except for station 1 distinctly decreased. However, the COD concentrations of the surface waters showed no distinct decrease trends at all stations. In the concentrations of nutrients (DIN and DIP) of both surface and bottom waters, there were tremendous decrease trends at all stations. Therefore, these distinct decrease trends of the COD in bottom waters and the nutrients in surface and bottom waters of Jinhae Bay could have been associated with water improvement actions such as TPLMS (total pollution load management system).