• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.655-667
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• 2009

An experimental study is performed on reducing the pollutants supplied by storm water through enhancing efficiency of SS from the detention storage tank where CSOs are kept temporarily before discharge to the receiving water system. SS removal efficiency is investigated in accordance with various conditions of the detention pond-such as its length, the existence of training wall, and the use of gravel filling. The removal efficiency is strongly affected by the detention pond's length until the critical falling distance of the suspended solids is reached. For cases where the tank has a length longer than this critical condition, the removal rate shows less sensitivity. To enhance the SS removal efficiency of tanks of shorter than the critical length, we studied alternative types of tank in which inside training walls are installed. The results showed improvement of 14 to 37% in removal efficiency in 2hours detention(2 training walls). The important factor in achieving a high SS removal rate is ensuring the critical length of the detention pond, but for the cases where the basin length cannot be guaranteed, baffles or a gravel filling scheme may be introduced to attain considerable efficiency. The results of studying and comparing different storage tank conditions show that, in terms of elimination efficiency, a storage tank with gravel filling and training walls > a storage tank with gravel filling > a storage tank with training walls > an empty tank. The experimental results should contribute to development of related further research, by empirically verifying the already assumed importance of critical falling distance, training walls, and gravel filling schemes.

• Spatial Information Research
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• v.1 no.1
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• pp.39-53
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• 1993

A geographical information systems(GIS) was a useful aid in the assessment of urban nonpoint source pollution and the development of a pollution control strategy. The GIS was used for data integration and display, and to provide data for a nonpoint source model. An empirical nonpoint source loading model driven by land use was used to estimate pollutant loadings of priority pollutant. Pollutant loadings were estimated at fine spatial resolution and aggregated to storm sewer drainage basins(sewershedsl. Eleven sewersheds were generated from digital versions of sewer maps. The pollutant loadings of individual land use polygons, derived as the unit of analysis from street blocks, were aggregated to get total pollutant loading within each sewershed. Based on the model output, a critical sewershed was located. Pollutant loadings at major sewer junctions within the critical sewershed were estimated to develop a mi t igat ion strategy. Two approaches based on the installat ion of wet ponds were investigated -- a regional approach using one large wet pond at the major sewer outfall and a multi-site approach using a number of smaller sites for each major sewer junction. Cost analysis showed that the regional approach would be more cost effective, though it would provide less pollution control.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.105-114
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• 2008

Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Separated sewer overflows(SSO) have been considered as a major cause of water-quality deterioration of natural water-courses in the vicinity of the heavily urbanized areas. The factors defining the magnitude and occurrence of SSO are site-specific. It is important to know exact properties of pollutants contained in SSO to address water quality impacts that are caused by SSO inputs to the receiving waters. Site and event parameters found to have significant influences on urban runoff pollutant EMCs include total event rainfall, antecedent dry period, rainfall intensity. In this study, a field survey was carried out in some selected areas of Cheongju city. Literature from previous similar studies was consulted and some important factors affecting the runoff characteristics of urban drainage areas were analyzed for some selected survey points. It was found that the factors most affecting BOD are the number of dry days prior to rainfall and the intensity of the rainfall. The factor most affecting CODcr is the number of dry days prior to rainfall. The factors most affecting SS are the amount of rainfall and the number of dry days prior to rainfall. The factor most affecting TN is the amount of rainfall. The factor most affecting TP is the amount of rainfall and the number of dry days prior to rainfall.

• KIEAE Journal
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• v.7 no.4
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• pp.9-15
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• 2007

As environmental problems and water-shortage phenomenon become a global issue, many states look for the effective method to use water resources. So, decentralized rainwater management is recognized as a new water management system that rainwater can be infiltrated and used on-site. But it is little difficult to build a park, lake, and forest for evaporating rainwater in city because the land price of city is very high. In order to build an excellent infiltration system for a dwelling and a park in Korea, KICT has developed Linear infiltration system. This infiltration system is consist of first flush treatment, storage and infiltration, overflow control system. These elements are connected closely and working as a combined system. A storm sewer can be changed by the linear infiltration system. This study is to show real application idea about Linear infiltration system with improving some detail in apartments. For this purpose, we devide application idea into the artificial ground and the natural ground and each ground type, suggest a method to cooperate with the other landscape and linear infiltration system. Through this study, we came to recognize a recognition difference of an expert and a commoner about decentralized rainwater management.

• KIEAE Journal
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• v.6 no.3
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• pp.3-10
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• 2006

As environmental problems and water-shortage phenomenon become a global issue, many states look for the effective method to use water resources. So, decentralized rainwater management is recognized as a new water management system that rainwater can be infiltrated and used on-site. But it is little difficult to build a park, lake, and forest for evaporating rainwater in city because the land price of city is very high. In order to build an excellent infiltration system for a dwelling and a park in Korea, KICT has developed Linear infiltration system. This infiltration system is consist of first flush treatment, storage and infiltration, overflow control system. These elements are connected closely and working as a combined system. A storm sewer can be changed by the linear infiltration system. This study is to make design guideline using Linear infiltration system in apartment house. So ATV-DVWK-M13, FLL and present condition of Korean rainwater system were analyzed and the guidelines direction were set up. Through this study, a foundation is prepared to build the decentralized rainwater management of apartment house.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.1-8
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• 2005

In this study, a numerical model combined by a river model and an inland model developed to simulated a flood event. The river model describing an inundation in a river solves the two-dimensional Saint Venant equations with a finite difference method. The inland model based on the ILLUDAS describes the conveyance capacity of a storm sewer system. The combined model is applied to a real situation. The model simulates reasonably the real flood event occurred in a river and inland simultaneously.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.61-65
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• 2008

Urban flooding with surcharges in sewer system was investigated because of unexpected torrential storm events these days, causing significant amounts of human and economic damages. Although there are limitations in forecasting and preventing natural disasters, integrated urban flooding management system using the SWMM engine and Web technology will be an effective tool in securing safety in operating Bi-modal transportation system. In addition, the integrated urban flooding management system can be linked with general and transportation-related disaster management system in the future. In this study, With simulated values by the SWMM, which is a core engine of the Bi-modal disaster management system, flash flooding area estimation module was developed. Thus, the SWMM system codes were modified and new module was developed and integrated with the existing SWMM interface using the Delphi programming language. The flash flooding area estimation module is fully integrated with the SWMM interface, thus the area is estimated on-the-fly inside the system.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.117-124
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• 2005

Appropriate removal of pollutants from combined sewer overflows(CSOs) and stormwater runoff is of primary concern to watershed managers trying to meet water quality standards even under a wet weather condition. Harmful substances associated with particles besides TSS and BOD are subjected to removal prior to discharge into the natural waters. Effectiveness of five major hydrodynamic separation technologies, Vortechs, Downstream Defender including Storm King for CSOs control, CDS, Stormceptor, and IHS, were evaluated in this study. There is not sufficient information for accurate evaluation of the removal efficiency for the pollutants from the stormwater runoff and CSOs. Based upon limited engineering data, however, all technologies were found to be effective in separation of heavy particles and floating solids. Technologies utilizing screens seem to have advantage in the treatment capacity than the other technologies relied fully on hydrodynamic behavior. The IHS system seems to have a strong potential in application for control of CSOs because of unique hydrodynamic behavior as well as a flexibility in opening size of the screens. Size of the particulate matter in the CSOs and stormwater runoff is found to be the most important parameter in selection of the type of the hydrodynamic separators. There exists an upper limit in the solids removal efficiency of a hydrodynamic separator, which is strongly dependent upon the particle size distribution of the CSOs and stormwater runoff.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1089-1094
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• 2009

The SWMM (Storm Water Management Model) was applied to Princeton University campus, USA to predict the change of the runoff characteristics. Topography and infra structure of urban area are used in detail and watershed is made as form of regular square to improve the efficiency of data. Princeton campus was divided into 131 sub-basins and model input parameters were obtained from DEM (Digital Elevation Model), land use type, and campus management map, etc.. The model was validated based on the measured meteorological data. The validated model was used to analyze the change of the runoff characteristics according to urbanization, which are two different scenarios: 50% and 100% increase of impervious area. The increase of impervious area causes the increase of runoff, especially in the first-flush.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.989-996
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• 2009

Recently, use of the GIS (Geographic Information System) for the disaster of the urban inundation is increasing. The digital disaster map is the system which analyzes the occurrence area of inundation in the past and forecasts the flood areas by the hydrology method. The development of the system which simulates the flood forecast area by the SWMM(Storm Water Management System) and hydrology method and displays the danger areas is required for the construction of the inundation forecast system. And the spatial database which contains information of the urban facilities such as the street and building and the sewer system such as the manhole and drainage and the result of the hydrology analysis is constructed. In this paper, we propose the method for transforming the Shape File in ESRI into the Oracle spatial database to construct the spatial data for the drainage systems and urban facilities using the Shape File format in the ESRI. We suggest the algorithm for the transformation of the data format, and develop the prototype system to display the inundation area using the spatial database.