• KCID journal
• /
• v.9 no.2
• /
• pp.59-67
• /
• 2002

Considering complexity of industry and environmental surroundings of Geum river basin, factors of environmental pollution are very complicated and multi-changed. It is very needed to survey the discharge, water quality change and pollutant loading from up

• Proceedings of the Korea Water Resources Association Conference
• /
• 2003.05b
• /
• pp.871-874
• /
• 2003

• Korean Journal of Environmental Agriculture
• /
• v.19 no.3
• /
• pp.252-258
• /
• 2000

SWMM and WASP5 were applied for pollutant loading estimate from watershed and reservoir water quality simulation, respectively, to predict estuarine reservoir water quality. Application of natural systems to improve estuarine reservoir water quality was reviewed, and its effect was predicted by WASP5. Study area was the Hwa-Ong reservoir in Hwasung-Gun, Kyonggi-Do. Procedures for estimation of pollutant loading from watershed and simulation of corresponding reservoir water quality were reviewed. In this study, SWMM was proved to be an appropriate watershed model to the nonurban area, and it could evaluate land use effects and many hydrological characteristics of catchment. WASP5 is a well known lake water quality model and its application to the estuarine reservoir was proved to be suitable. These models are both dynamic and the output of SWMM can be linked to the WASP5 with little effort, therefore, use of these models for reservoir water quality prediction in connection was appropriate. Further efforts to develop more logical and practical measures to predict reservoir water quality are necessary for proper management of estuarine reservoirs.

• Journal of Korean Society on Water Environment
• /
• v.22 no.2
• /
• pp.314-320
• /
• 2006

Diffuse pollution from an urban area contributes to the significant pollution loading to a receiving water body. In this paper, rainfall runoffs from an urban basin with combined sewer systems located in the city of Daejeon were monitored to measure the rainfall runoff discharge rates and pollutant concentrations. Strong first flush effects were observed for all monitored rainfall runoffs. The first flush effects were closely related to rainfall intensity, while suspended solids were closely related to pollutant constituents. The observed averaged Event Mean Concentrations (EMCs) of Combined Sewer Overflows (CSOs) were 536.1 mg SS/L, 467.7 mg CODcr/L, 142.7 mg BOD/L, 16.5 mg TN/L, and 13.5 mg TP/L. Storage volumes for containing the first flush to improve water quality of the receiving stream can be estimated based on suspended solid concentration. In this study, retainment of the first flush equivalent to 5mm of precipitation could reduce diffuse pollution loading induced by CSOs to a receiving water body by up to 80% of suspended solid loading.

• Journal of Korea Water Resources Association
• /
• v.45 no.11
• /
• pp.1121-1130
• /
• 2012

Projected changes and their impacts on water quality are simulated in response to climate change stressors. CGHR (T63) simulation on the A1B scenario is converted to regional scale data using a statistical down-scaling method and applied to SWAT model to assess water quality impacts in Nakdong River basin. The results demonstrate that rainfall-runoff and pollutant loading in the future (2011~2100) will clearly increase as compared to the last 30-year average. The rate of pollutant loading increase is expected to continue its acceleration until 2040s. Runoff also shows similar patterns to the precipitation, increasing by 60%. Accordingly, the runoff increase results in escalation of pollutant loading by 35~45% for TSS and 5~20% for T-P. This phenomenon is more pronounced in the upper basin during winter and spring season.

• Journal of Environmental Impact Assessment
• /
• v.8 no.1
• /
• pp.93-105
• /
• 1999

Lately water quality of Daechong Reservoir has become more eutrophicated than ever before and there has been much concern over especially the eutrophication of the embayment near Daejon and Chongju Water Intake Tower every summer. The purpose of this study is to predict the impact of change in the pollutant loading, flowrate, nitrogen and phosphorus release from sediment, SOD(sediment oxygen demand) upon the water quality of Daechong Reservoir by WASP5/EUTR05 in order to suggest water quality management alternatives. The data of Sep. 1995 were used for the calibration of the model and those of Sep. 1997 was for verification. The result of the modeling can be summarized as follows. 1. The 50% increase(decrease) of pollutant loading has caused that of T-N concentration by 0.10-0.14 mg/l, T-P concentration by 0.003-0.005 mg/l, and CBOD concentration by 0.16-0.18 mg/l. But the ratio of DO change by the change of pollutant loading was relatively small. 2. The sensitivity test of NH4 flux to T-N and that of P04 flux to T-P shows that T-N and T-P concentration were changed more in the epilimnion segments (SEG4, SEG5, SEG6, SEG7) than the other segments. As SOD increases, DO was predicted to decrease more especially in the hypolimnion (SEG9-SEG14). 3. As flowrate increase, the concentration of T-N, T-P, and CBOD were predicted to decrease, but DO concentration increased especially in the hypolimnion segments(SEG11, SEG12, SEG13, and SEG14). As the flowrate changed from $119m^3/sec$ to $50m^3/sec$, the concentration of T-N and CBOD in the hypolimnion was predicted to decrease.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.39 no.5
• /
• pp.97-108
• /
• 1997

Natural wastewater treatment systems using the constructed wetland system were evaluated for the wastewater from the industrial complex in rural areas. For the treatment of wastewater from the industrial complex in rural area, a pilot plant of the constructed wetland system was installed at Baeksuk agri-industrial complex in ChunahnCity, Chunchungnam-Do. The experiment with this pilot plants was performed for 1996 and 1997. Results of the study were summarized as follows. For the BOD and COD, when the pollutant loading of them was about 1 3.8g/$m^2$. day (the concentration was l24.0mg/${\ell}$) arid 24.4g/$m^2$.day(the concentration was 220.Omg/${\ell}$), the removal rate of them was high, 90.2% and 93.4%, respectively. For the SS, the effluent concentration was consistently lower than the water quality standard even though the influent concentration varied significantly, which showed that SS was removed by the system effectively which consist of soil and plants. For the T-N and T-P, when the influent pollutant loading of them were moderately high, 2.8g/$m^2$.day to 7.4g/$m^2$. day(concentration 25.0mg/${\ell}$ to 49.7mg/${\ell}$) for T-N and 1.0g/$m^2$.day to 2.6g /$m^2$.day(concentration 8.6mg/${\ell}$ to 14.7mg/${\ell}$) for T-P, the removal rate of them were 86.5% and 94.0%, respectively. The removal rate by the flow distance increased rapidly in the first 4m from the inlet zone, and gradually there after. The width of system was 2m. Overall, the result showed that constructed wetland system is a feasible alternative for the treatment of wastewater from industrial complex in rural areas. Compared to existing systems, this system is quite competitive because it requires low capital cost, almost no energy and maintenance, and therefore, very cost effective.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.51 no.5
• /
• pp.87-94
• /
• 2009

The objectives of this paper were to estimate cell based pollutant loadings for total maximum daily load (TMDL) programs and to evaluate the applicability of the agricultural nonpoint source (AGNPS) model for an intensive agricultural watershed in Korea. The model was calibrated and validated at a watershed of 384.8 ha of drainage area using the observed data from 1996 through 2000 in terms of runoff, suspended solid, total nitrogen, and total phosphorus on a hourly basis. Analysis of spatial variations of pollutant loadings for rainfall frequencies of various intensities and durations were conducted. In addition, the validated model was applied to estimated the TMDL removal efficiency for best management practices (BMPs) scenarios which were selected by taking into account the pollutant characteristics of the study watershed. The model can help to understand the problems and to find solutions through landuse changes and BMPs. Thus, the method used for this study was able to identify TMDL quantitatively as well as qualitatively for various sources pollution that are spatially dispersed. Also it provides an assessment of the impact of BMPs on the water bodies studied, allowing the TMDL programs to be complemented more effectively.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.2
• /
• pp.107-114
• /
• 2004

NPS pollutant loads from sandy clayey and clayey loam runoff plots were measured. Runoff plots were 2$\times$10 m in size and 8~10% in slope and paddy area was 4,620 $m^2$. Soybean, corn, tobacco and control (natural weed) were cultured. Precipitation during the growing season of June to October, 2002 was 869.5 mm. Runoff and water quality were measured more than 10 times during the measurements depending on the growing stage. Pollutants loads were estimated by using respective concentration and runoff volume. Runoff occurred when daily rainfall exceeded about 30 mm. The largest runoff was observed from the paddy but pollutant loads were larger from upland crops than those from paddy. SS loads from paddy and upland were 1.4 ton/ha/yr and 3.1~4.3 ton/ha/yr, respectively. COD loads 30 kg/ha/yr and 66~90 kg/ha/yr, T-N loads 13 kg/ha/yr and 14~23 kg/ha/yr, T-P loads 1 kg/ha/yr와 4 kg/ha/yr, nitrate nitrogen loads 1 kg/ha/yr and 4~8 kg/ha/yr, and phosphate phosphorus loads 0 kg/ha/yr and 4~6 kg/ha/yr, respectively. It was concluded that NPS pollutant loads from upland crop culture have greater impact on the quality of the receiving water body than those from paddy culture.

• Korean Journal of Ecology and Environment
• /
• v.42 no.2
• /
• pp.200-211
• /
• 2009

A mathematical modeling program called Soil and Water Assessment Tool (SWAT) developed by USDA was applied to Kyongan stream watershed. It was run under BASINS (Better Assessment Science for Integrating point and Non-point Sources) program, and the model was calibrated and validated using KTMDL monitoring data of 2004${\sim}$2008. The model efficiency of flow ranged from very good to fair in comparison between simulated and observed data and it was good in the water quality parameters like flow range. The model reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The results of pollutant loads estimation as yearly (2004${\sim}$2008), pollutant loadings from 2006 were higher than rest of year caused by high precipitation and flow. Average non-point source (NPS) pollution rates were 30.4%, 45.3%, 28.1% for SS, TN and TP respectably. The NPS pollutant loading for SS, TN and TP during the monsoon rainy season (June to September) was about 61.8${\sim}$88.7% of total NPS pollutant loading, and flow volume was also in a similar range. SS concentration depended on precipitation and pollution loading patterns, but TN and TP concentration was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. SWAT based on BASINS was applied to the Kyongan stream 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 non-point sources in watershed scale.