• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.628-631
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• 2007

One of the structural measures for the peak flow reduction is infiltration facilities. There are many types in infiltration facilities - infiltration basin, trench, bed, porous pavement, percolated subdrain, dry well. In this study runoff reduction effect of infiltration trench is analyzed by WinSLAMM. Runoff reduction effect is investigated by each design rainfall and temporal pattern of rainfall particularly. The biggest reduction is shown in Yen and Chow's temporal pattern of design rainfall and the smallest reduction is shown in Huff's first quartile pattern. Runoff reduction rate is presented about 6 to 14 percentage, and the larger return period, the smaller runoff reduction rate.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.133-141
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• 2011

Urban development of basin causes increasing runoff volume and peak flowrate and shortening in time of concentration, which may cause frequent flooding downstream. An infiltration facilities are operated as a method of reducing flood discharge of urban rivers and peak flowrate. There are various types of infiltration facilities like infiltration trench and porous pavement. In this study, runoff reduction effect due to installation of infiltration facilities are performed and focused on $0.18km^2$ residential area of Ok-kye dong and $0.67km^2$ industrial area of Gong-dan dong in Gumi City. The analysis is fulfilled with comparison of total runoff volume and runoff reduction volume by using the WinSLAMM and the relation equation between area ratio of infiltration facilities and ratio of runoff reduction are derived and peak flow reduction effect for installation of infiltration facilities is analyzed.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.2
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• pp.13-27
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• 2008

This paper aim to reorganize zoning areas for decreasing first-flush runoff contamination in a separated sewer system via suitability analysis, and to simulate the discharge pollution loads of first-flush runoff using SWMM. For these purposes, diffuse pollution, which is accumulated on a surface and first-flush runoff flow were investigated. Suitability conditions for zoning were defined using the results of these investigation and suitable zoning areas were analyzed for the each condition. AHP analysis was conducted to establish weights of the suitability conditions. The most suitable zoning areas were analyzed via overlaying weights and suitability conditions. From the result, it was noted that the most suitable zones for detached houses & apartments are location they already occupied. Some school areas analyzed were found to be suitable as commercial centers. Some zones within the area analyzed were found to be suitable for commercial zones. From results obtained from simulation, the zone re-organization showed BOD and SS concentration to reduce from 91.2% to 0.09% ans 72.74% to 0.31% respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.1
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• pp.39-51
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• 1999

This study has an object to evaluate runoff characteristics with ILLUDAS model and SWMM owing to each rainfall distribution type of Huff's quartile and each rainfall duration time of 30 ,60, 120 and 180 minutes. As a result of this study, Type-Ⅰ Extreme (TIE) rainfall distribution pattern with Huff's 2nd quartile is adequate for Cheju volcanic island . To decide optimal rain fall duration , time of concentration and critical duration should be compared and analyzed each other. In this study, 30 and 120 miniutes were suggeste to iptiaml duration time of A and B study basins. It is concluded that the magnitude of peak runoff discharge is maximum with Huff's 4th quartile, and that of total runoff volume is maximum with Huff's 4th quartile for ILLUDAS model and with Huff's 1st quartile for SWMM. As rainfall duration time increasing is increasing . Also in case of total runoff volume, volumen by SWMM is less than by ILLUDAS model as to variation ratio of total runoff volume in A and B study basin. Therefore, the resulots of this study canb e sued as basic data in determining adequate rainfoal duration time and rainfall distribution type and used for urban drainage systems analysis and design at small urbanization catchment is Cheju volcanic island.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.490-497
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• 2007

A Combined sewer overflows (CSOs) are themselves a significant source of water pollution. Therefore, the control of urban drainage for CSOs reduction and receiving water quality protection is needed. Examples in combined sewer systems include downstream storage facilities that detain runoff during periods of high flow and allow the detained water to be conveyed by an interceptor sewer to a centralized treatment plant during periods of low flow. The design of such facilities as stormwater detention storage is highly dependant on the temporal variability of storage capacity available (which is influenced by the duration of interevent dry periods) as well as the infiltration capacity of soil and recovery of depression storage. As a result, a continuous approach is required to adequately size such facilities. This study for the continuous long-term analysis of urban drainage system used analytical probabilistic model based on derived probability distribution theory. As an alternative to the modeling of urban drainage system for planning or screening level analysis of runoff control alternatives, this model have evolved that offer much ease and flexibility in terms of computation while considering long-term meteorology. This study presented rainfall and runoff characteristics of the subject area using analytical probabilistic model. This study presented the average annual COSs and number of COSs when the interceptor capacity is in the range $3{\times}DWF$ (dry weather flow). Also, calculated the average annual mass of pollutant lost in CSOs using Event Mean Concentration. Finally, this study presented a decision of storage volume for CSOs reduction and water quality protection.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.181-187
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• 2009

In this study, a runoff hydrograph and runoff volume were calculated by using the kinetic wave theory for small urban watersheds based on the concept of low impact development(LID), and the effective imperviousness was estimated based on these calculations. The degree of sensitivity of the effective imperviousness of small watersheds to the impervious to pervious area ratio, infiltration capability, watershed slope, roughness coefficient and surface storage depth was then analyzed. From this analysis, the following conclusions were obtained: The effective imperviousness and paved area reduction factor decreased as the infiltration capability of pervious area increased. As the slope of watersheds becomes sharper, the effective imperviousness and the paved area reduction factor display an increasing trend. As the roughness coefficient of impervious areas increases, the effective imperviousness and the paved area reduction factor tend to increase. As the storage depth increases, the effective imperviousness and the paved area reduction factor show an upward trend, but the increase is minimal. Under the conditions of this study, it was found that the effective imperviousness is most sensitive to watershed slope, followed by infiltration capability and roughness coefficient, which affect the sensitivity of the effective imperviousness at a similar level, and the storage depth was found to have little influence on the effective imperviousness.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.691-699
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• 2010

In recent years, increases in impervious areas with rapid urbanization and land use changes are causing numerous hydrologic cycle and environmental problems. Impermeable pavement have a various defect such as collection rainwater, decreasing of sliding resistance, and etc. In this study, the hydrologic cycle effect of permeable pavement were analyzed by the experiment and the numerical simulation. The numerical model used was a modified SWMM especially for considering the hydrologic cycle effect of permeable pavement. The parameters of modified SWMM were revised by the experimental results. Also, the effects of runoff quantity reduction are reviewed when permeable pavement is applied to Incheon Cheongna watershed. The hydrologic cycle analysis of Incheon Cheongna watershed, continuous simulations of urban runoff were performed. The analysis results of permeable pavement setup effect on runoff are follows: the surface runoff after permeable pavement setup decreases to 74.35% of the precipitation whereas the surface runoff before permeable pavement setup amounts to 81.38% of the precipitation; the infiltration after permeable pavement setup increases to 15.13% of the precipitation whereas the infiltration before permeable pavement setup amounts to 8.32% of the precipitation.

• Journal of Korea Water Resources Association
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• v.42 no.3
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• pp.191-200
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• 2009

A localized torrential rainfall and flash floods which are more frequently occurred by extraordinary atmospheric phenomena and rising sea surface temperature require more hydrological data collecting and analysis for small watershed. Urban watershed hydrological data monitoring system is needed because of big flood potential damage and lack of urban watershed hydrological data. Therefore, Urban Flood Disaster Management Research Center operates small experimental catchments(Sinnae1, Gunja, and Children's Park) observing and analyzing hydrological data(rainfall, stage, and discharge). In this study, the discharge of combined sewage for Gunja experimental drainage is analyzed with weekly data and day of the week data. Through several analyses in analyzing the urban runoff characteristics and managing the urban sewage system, direct runoff is calibrated and verified by the estimated values of rainfall-runoff model(SWMM).

• Journal of Environmental Science International
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• v.25 no.11
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• pp.1499-1509
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• 2016

This study was performed to analyze the effects of a water circulation green area plan on non-point source pollution in Gimhae South Korea. A quantitative analysis of Arc-GIS data was conducted by applying a watershed model based on Fortran to investigate the changes to direct runoff and pollution load. Results showed that prior to the implementation of the water circulation green area plan in Gimhae, direct runoff was $444.05m^3/year$, total biological oxygen demand (BOD) pollution load was 21,696 kg/year, and total phosphorus (TP) pollution load was 1,743 kg/year. Implementation of the development plan was found to reduce direct runoff by 2.27%, BOD pollution load by 1.16% and TP pollution load by 0.19% annually. The reduction in direct runoff and non-point source pollution were attributed to improvements in the design of impermeable layers within the city.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.559-571
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• 2013

Recently, due to increase of the impervious layer, the storage of surface layer has been reduced. Otherwise the peak runoff and the total surface runoff have been raised. Because of larger amount of the peak runoff and the rapid time of concentration, the flood damage of the urban watershed was increased. The groundwater level is descended by reducing the amount of rainfall that infiltrated into the soil. Thereby the hydrologic cycle is degenerated by the dry stream. Therefore, in this study, the evaluation and the quantitative analysis of the percolation effect were performed through the infiltration experiment of permeable pavement, which is one of the ways that can reduce the problem of the dry stream. Also the SWMM model is used to analyze the effect of the hydrologic cycle for permeable pavement in Changwon stream and Nam stream watersheds, with the coefficient of permeability from the infiltration experiments.