• Journal of the Korean Society for Marine Environment & Energy
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• 제6권3호
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• pp.63-71
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• 2003

This study investigated about the seasonal variation of pollutant loads flowing into the Yeong-il bay from constructing Tank model which is the simulation model to evaluate the daily river discharge and pollutant load in the Hyeong-san river watershed. The estimated annual average river discharge of Hyeong-san river flowing into Yeong-il bay is about 878.34×10/sup 6/㎥/year which is about 73% of annual average of total precipitation in Hyeong-san river watershed. The annual average of pollutant load flowing into Yeong-il bay was estimated each 15.11 ton-COD/year, 23.24 ton-SS/year, 10.65 ton-TN/year, and 0.54 ton-Tp/year. For the seasonal variation of pollutant loads, it was tended as increasing of river discharge as increasing of inflow pollutant loads at June and July of summer and October of autumn. The main source of pollutant loads was found to be the Pohang city and Pohang industrial complex which are located near the mouth of Hyeong-san river. Therefore, for effective water quality management of Yeong-il bay, the counterplan to reduce pollutant loads from the main source of pollutant loads is required.

• Journal of The Korean Society of Agricultural Engineers
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• 제46권2호
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• pp.107-114
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• 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.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 한국해양공학회 2004년도 학술대회지
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• pp.210-215
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• 2004

The Purpose of this study are to develop the simulation(Tank model, Rainfall-runoff model) for the estimation of wily river discharge and for evaluation of wily pollutant loads from the watersheds of the objected basin area. As apply this constructed Tank model to Nakdong river region, we evaluated the wily river discharge of Nakdong river from use-land conditions, precipitation and evaporation data of 3 years(from 1998 to 2000) and investigate the seasonal fluctuation of SS, COD, TN, TP inflowing into Nakdong river. The result shows that summer has high pollutant level than winter in seasonal characteristic and the down stream has high pollutant level than the upper stream. The annual average of SS, COD, TN, TP flawing in Nakdong river(Samranjin) was estimated each 691ton-COD/year, 1854.2ton-SS/year, 382.8ton-TN/year and 13.0ton- TP/year.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.456-459
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• 2001

A relationship between the water quantity and the inflow pollutant loads of BOD, TN, and TP in So-okcheon of the upper Keum river in 2000 was investigated in this study. Daily streamflow of So-okcheon needed to compute the pollutant loads was estimated by the DAWAST model, because there is no measurement of the discharge. From a relative function of the inflow pollutant loads using DAWAST, BOD can be estimated by the relation of $y=145.31x^{1.06},\;TN\;by\;y=598.11x^{0.90}\;and\;TP\;by\;y=39.60x^{0.89}$.

• Journal of Korean Society on Water Environment
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• 제25권4호
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• pp.580-588
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• 2009

In this study daily flow rates and delivered pollutant loads of Nakdong river basin are simulated with modified TANK model and minimum variance unbiased estimator. Based on the simulation results, flow duration curves, load duration curves, and delivery ratio duration curves have been established. Then GIS analysis is performed to obtain several hydrological geomorphic characteristics such as watershed area, stream length, watershed slope and runoff curve number. Finally, multiple regression analysis is carried out to estimate empirical equations for pollutants delivery ratio. The results show that there is positive relation between the flow rates and delivery ratios, and the proposed empirical formulas for delivery ratio can predict well river pollutant loads.

• Journal of Korean Society on Water Environment
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• 제25권1호
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• pp.125-135
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• 2009

Reliable long-term flows by SWAT-K model were applied to the relationship between stream flow and pollutant load derived from 8-day measured data of Ministry of Environment (MOE) in order to obtain continuous loadograph and evaluate accuracy in water quality modeling for the Chungju dam watershed. The measured flow were compared with flow duration curve from the model, and it showed that measured values corresponded to the almost full range of stream flow conditions except at Odae A. And there was significant relationship ($R^2=0.60{\sim}0.97$) between measured flow and water quality load at all unit-watersheds. Applying this relationship to simulated flows, continuous loadograph was obtained and compared with modeled pollutant loads. Although there were some differences during some dry and flood seasons, those were not significant and overall trend showed a good agreement. From the results, we would be able to derive a continuous loadograph based on measured data at total maximum daily loads (TMDLs) unit-watersheds on a national scale, in which stream flow and water quality have been measured at 8-day intervals since 2004, and this could be helpful to utilize distributed water quality models with difficulty in calibrating and validating parameters from lack of measured data at present.

• Journal of Ocean Engineering and Technology
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• 제17권4호
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• pp.23-30
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• 2003

This study investigates the seasonal variation and spatial distribution characteristics of pollutant load, as executing the quality valuation of pollutant load inflowing into Yeong-il Bay from on-land including the Hyeong-san River. Annual total pollutant generating rate from Yeong-il Bay region are 202ton-BOD/day, 620ton-SS/day, 42ton-TN/day, and 16ton-TP/day, respectively. Particularly, the generating ration of the pollutant loads from the Hyeong-san River is greater than that of any other watershed of the Yeong-il Bay, of which BOd is about 78.2％, SS 88.5％, T-N 62.5％, T-P 73.1％, As calculating Tank model with input value of daily precipitation and evaporation of 2001 year in drainage basin of the Hyeong-san River, the estimated result of the annual river discharge effluence from this river is 830106㎥, As a result to estimating annual effluence rate outflowing at the rivers from each drainage basin. annual inflow pollutant rates are 10,633ton-BOD/year, 19,302ton-SS/year, 15,369ton-TN/year, 305ton-TP/year, respectively. The population congestion region of the Pohang-city is a greater source of pollutant loads than the Neang-Chun region with wide drainage area. Therefore, the quantity of TN inflowing into Yeong-il Bay is much more than T-P. The accumulation of pollutant load effluenced from on-land will happen at the inner coast region of Yeon-il Bay. Finally, We would make a prediction that the water quality will take a bad turn.

• Journal of Korean Society on Water Environment
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• 제30권3호
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• pp.340-350
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• 2014

Recently, TMDL has been implemented to estimate the amount of pollutant loads and to establish proper mitigation strategy to decrease the pollutant loads by the Ministry of Environment. To estimate the amount of pollutant loads with reasonable accuracy, securing landcover map with periodically updating is essential. However, in reality, due to the technical and financial difficulties, the landcover map has not been updated annually. Hence, this study mainly aims to suggest an effective GIS-based updating method in order to promote utilization of landcover map in the estimation of pollutant loads. Bupyeong-gu at the City of Incheon with the total area of $31.98km^2$ was chosen for this study and spatial data including digital topographic maps, ortho aerial photo, and satellite images were collected and utilized. A total of 7,235 feature entities were newly produced through the updating process of five steps and it was revealed that the classification of landcover with the total area of $3.34km^2$ was to be changed. The validity and feasibility of the suggested method were proved with the accuracy of 97.9% from the field verification. Further study needs to be made for devising more automated method to update landcover map to facilitate TMDL for individual local governments.

• Journal of The Korean Society of Agricultural Engineers
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• 제51권6호
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• pp.25-31
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• 2009

In this study, pollutant loads delivery ratio by flow duration in Hwangryoung A watershed was estimated. The delivery ratio was estimated with measured data by Ministry of Environment(MOE) and the regression equation based on geomorphic parameters. Eight day interval flow data measured by the MOE were converted to daily flow to calculate daily load and flow duration curve by correlating data of neighboring station which has daily flow data. Regression equation developed by previous study was tested to study watershed and found to be satisfactory. The delivery ratios estimated by two methods were compared. For the case of Biochemical oxygen demand(BOD), the delivery ratios of low flow condition were 7.6 and 15.5% by measured and regression equation, respectively. Also, the delivery ratios of Total phosphorus(T-P) for normal flow condition were 13.3 and 6.3% by measured and regression equation, respectively.

• Journal of Korean Society on Water Environment
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• 제25권1호
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• pp.58-68
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• 2009

Low impact development (LID) technique is relatively new concept to reduce surface runoff and pollutant loading from land cover by attempting to match predevelopment condition with various integrated management practices (IMPs). In this study, computational model for designing and evaluating LID, named LIDMOD, was developed based on SCS-CN method and applied at Andong bus terminal to evaluate LID applicapability and design retention/detention area for volume or peak flow control. LIDMOD simulated with 21 years simulation period that yearly surface runoff by post-development without LID was significantly higher than that with LID showing about 2.8 times and LID could reduce efficiently yearly surface runoff with 75% reduction of increased runoff by conventional post development. LIDMOD designed detention area for volume/peak flow control with 20.2% of total area by hybrid design. LID can also efficiently reduce pollutant load from land cover. Pollutant loads from post-development without LID was much higher than those from pre-development with showing 37 times for BOD, 2 times for TN, and 9 times for TP. Pollutant loads from post-development with LID represented about 57% of those without LID. Increasing groundwater recharge reducing cooling and heating fee, creating green refuge at building area can be considered as additional benefits of LID. At the point of reducing runoff and pollutant load, LID might be important technique for Korean TMDL and LIDMOD can be useful tool to calculate unit load for the case of LID application.