• Water for future
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• v.26 no.3
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• pp.125-135
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• 1993

This study was conducted for two purposes. The first was the selection of the proper model for the urban runoff, and NPS(non-point source) loads and the second was the adjustment of the selected model through the calibration and the verification of the observed data on an urban drainage basin. The selected model for this study was the Storm Water Management Model(SWMM) developed and maintained by the US Environmental Protection Agency(EPA). In particular, the Runoff Block for the surface discharge and the Transport Block for the flow routing was used. The study basin is Youngdu basin, which is a typical developed urban drainage basin. The four rainfall events for the runoff and the two for the four NPS pollutants(SS, BOD, COD and TN) were used for the calibration and the estimation of the model parameters. This study performed the calibration with regard to the peak discharge, the time to peak discharge, the volume and the relative error for three items. It was shown that SWMM can successfully be used for the prediction of the runoff and the NPS pollutants discharge. The result of this study can be used as the basis for the analysis of the correlation between the runoff and the NPS pollutants discharges, and the analysis of the mass balance with the monthly and annual NPS loads in an urban drainage basin.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.4
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• pp.93-102
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• 1989

A runoff model is estabilished for the direct runoff hydrograph at the watershed outlet. The watershed is divided into subareas bounded by watershed lines of stream segment. Different storage elements are used to represent the subareas which simply translate rain-fall excess to runoff and transmit flow from an upstream areas. For transmit, the relationship between flowsection and runoff is expressed by the exponential function to represent the nonlinearity of lag time, and the relationship between flowsection and stream length is expressed by the 1st order equation to represent the effect of the travel length. The parameters of lag time can be obtained by stream magnitude and the effective rain fall is routed through the main stream. Application of the model to the Bochung river basin gives accurate results, especially for the peak runoff and peak time, and is approved to be used for the prediction by stream magnitude of small watershed having no runoff records.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.3
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• pp.91-98
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• 1998

In this study, the hydrological changes due to urbanization were investigated and fundamental theory and characteristics of typical urban runoff model such as ILLUDAS was studied. Above model was applied for urbanizing Dongsucheon basin, Incheon. The main parameters (II, IA, IS) which are included in model depending on runoff results were determined, and dimensionless values such as total runoff ratio($Q_{TR}$), peak runoff ratio($Q_{PR}$), and runoff sensitivity ratio ($Q_{SR}=Q_{TR}/Q_{PR}$) were estimated in order to evaluate and compare the characteristics of model based on relative sensitivity analysis.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.2
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• pp.134-142
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• 1997

This study was performed to evaluate the drain runoff characteristics from one paddy field, and to provide the basic data required for the determination of flood discharge and unit drainage water for drainage improvement and farmland consolidation. For this purpose, under the assumption that drain discharge from paddy field was similar to outflow of reservoir, runoff model based on storage equation was applied to the experimental field, and simulated results were compared to the measured discharge at weir point. To estimate effective storage volume of paddy field with water depth, 4 regression formula were examined such as linear, exponential, power, and combined. From the observed runoff characteristics, it was shown to be 3.3~16.3${\ell}$/sec in weir discharge, 57.2~98% in runoff ratio, and relative error of simulated result was 3.0~39.4%, 8.5 ~56.0 % for peak flow and runoff ratio, respectively. Curve number by SCS method was calculated as mean value of 96.4 using measured rainfall and runoff data, it was considered relatively high because paddy field has generally flooding depth contrary to the upland watershed area.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.2
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• pp.74-81
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• 1999

In this study, the hydrological changes due to urbanization were investigated and fundamental theory and characteristics of typical urban runoff model such as CHICAGO Model was studied. Above model was applied for urbanizing Dongsucheon basin, Incheon. The main parameters(CI, CP, CS) which are included in this model depending on runoff results were determined, and dimensionless values such as total runoff ratio($Q_{TR}$), peak runoff ratio($Q_{PR}$), and runoff sensitivity ratio($Q_{SR}=Q_{TR}/Q_{PR}$) were estimated in order to evaluate and compare the characteristics of model based on relative sensitivity analysis. Finally, applied model was proposed based on understanding of work types and established urban runoff models which can simulate well for areal development patterns and urban river basin.

• Water for future
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• v.24 no.2
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• pp.59-70
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• 1991

To simulate the mechanism of runoffs on seall watersheds, the ILLUDAS and the ILSD models are used in this study'. The transferability of these models to Korean watersheds and significant factors that could affect their applicability were examined through the analyzation of the hydrographs generated from runoff simulations. The runoff hydrographs from the watersheds with different urbanization rates are also simulated to investigate the degree of variation of the peak discharges the runoff rates, the runoff volumes and other hydrological factors related with urban runoff.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.3
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• pp.43-54
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• 2004

For a given watershed that consists of urbanized areas, it was essential to predict how the runoff characteristics, such as runoff peak and volume, and travel time, change with time far planning and designing various kinds of hydraulic facilities with given recurrence interval. In this study, Mushim stream watershed was simulated using HEC-HMS model to get runoff characteristics of an urbanization basin. The results was showed that runoff was increased $1794.20{\sim}2104.65\;m^{3}/s$> and $1751.90{\sim}1961.30\;m^{3}/s$ according to the increased of rainfall and CN value recurrence interval in years. Observed storm was increased $497.91{\sim}581.71\;m^{3}/s$ and $506.57{\sim}537.01\;m^{3}/s$ for increased of CN value and impervious area. This paper is also possible to evaluate the effect of urbanization quantitatively.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.493-505
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• 2013

This study was to investigate the runoff characteristics of non-point pollutants source at the urban area in Suwon city. The highest T-N and T-P concentration of rainfall runoff observed in agricultural area. In residential area, the highest $BOD_5$ and SS concentration of rainfall runoff was investigated. During rainfall events, the peak concentrations of SS and $BOD_5$ were observed after 1~2 hours of rainfall in urban area. Whereas, the peak concentrations occurred within 1~2 hours after rainfall and then the highest concentrations of SS and $BOD_5$ sharply decreased, showing strong first flush effect in urban area. The EMC results indicated that the highest value of T-N and T-P in agricultural area was observed. While residential area was shown the lowest EMC value as T-N and T-P. Non-point pollutant loads on the land use types in urban area were investigated in the order of residential>industrial>agricultural>highway. $BOD_5$ and SS loads on urban watershed were investigated in the order of Suwon>Hwangguji>Seoho>Wonchunri. Whereas, T-N and T-P loads on urban watershed were investigated in the order of Hwangguji>Suwon>Wonchunri>Seho.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.515-524
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• 1999

A methodology to resolve a TOPMODEL problem has been suggested, which is associated with the spatial distribution of soil moisture behaviour in a runoff mechanism. A procedure to integrate the spatial information of saturation deficit in the TOPMODEL reflects the connectivity of saturated area in a watershed. The developed algorithm includes an improved basis in tracing the runoff path without increasing the number of parameters. The performance of the developed algorithm has been tested to an upland subwatershed, namely Dongok, which is the IHP watershed located at Wichon, Korea. Comparing with the original statistical version of the TOPMODEL, it has been found that the suggested algorithm can relax an overestimation of peak rate in the runoff simulation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.709-721
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• 2008

This paper is to test the applicability of ModKIMSTORM (Modified KIneMatic Wave STOrm Runoff Model) by applying it to Namgangdam watershed of $2,293km^2$. Model inputs (DEM, land use, soil related information) were prepared in 500 m spatial resolution. Using five typhoon events (Saomi in 2000, Rusa in 2002, Maemi in 2003, Megi in 2004 and Ewiniar in 2006) and two storm events (May of 2003 and July of 2004), the model was calibrated and verified by comparing the simulated streamflow with the observed one at the outlet of the watershed. The Pearson's coefficient of determination $R^2$, Nash and Sutcliffe model efficiency E, the deviation of runoff volumes $D_v$, relative error of the peak runoff rate $EQ_p$, and absolute error of the time to peak runoff $ET_p$ showed the average value of 0.984, 0.981, 3.63%, 0.003, and 0.48 hr for 4 storms calibration and 0.937, 0.895, 8.08%, 0.138, and 0.73 hr for 3 storms verification respectively. Among the model parameters, the stream Manning's roughness coefficient was the most sensitive for peak runoff and the initial soil moisture content was highly sensitive for runoff volume fitting. We could look into the behavior of hyrologic components from the spatial results during the storm periods and get some clue for the watershed management by storms.