• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.1-11
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• 2009

Rapid visualization of flood area of downstream according to the dam effluent in flood season is very important in dam management works. Overlay zone of river bight should be removed to represent flood area efficiently based on flood stage which was modeled in river channels. This study applied drainage enforcement algorithm to visualize flood area considering river bight by coupling Coordinate Operation System for Flood control In Multi-reservoir (COSFIM) and Flood Wave routing model (FLDWAV). The drainage enforcement algorithm is a kind of interpolation which gives to advantage into hydrological process studies by removing spurious sinks of terrain in automatic drainage algorithm. This study presented mapping technique of flood area layer considering river bight in Namgang-Dam downstream, and developed system based on Arcobject component to execute this process automatically. Automatic extraction system of flood area layer could save time-consuming efficiently in flood inundation visualization work which was propelled based on large volume data. Also, flood area layer by coupling with IKONOS satellite image presented real information in flood disaster works.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.36-52
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• 2020

This study performed 2-D(two-dimensional) hydrodynamic analysis using EFDC in the Nakdong River. For the simulation of the flood season and non-flood season, the measured data including water level, weir outflow and tributary inflow were used, and the accuracy and applicability of the model were verified by comparing the measured water level and computed one. In addition, statistical quantitative assessment of the model performance was performed by estimating PBIAS, RSR, and RMSE for the computed water level. Then, the average velocity for each section between weirs was calculated by applying constant discharge conditions, and it was compared and verified with the measured velocity by Hydrological Survey Center. In this study, a simple method for estimating the arrival time was proposed, and it is expected that it will be practically applicable in field practices such as flood forecasting and warning.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3B
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• pp.169-174
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• 2012

For efficient water management in the Ara River during the flood season, applicability of flood simulation model in the ungaged Gulpo watershed has been tested. In the Gulpo River watershed, fundamental hydrologic data such as water level and flowrates are very limited and selection of the reliable hydrologic parameters are very important for model application. This study tested reliability of parameters estimated using the empirical equation based on the HEC-HMS runoff simulation. Also coupled with HEC-RAS hydraulic routing model, simulated flowrates from HEC-HMS has been compared with the observed water levels collected at the upstream and downstream of the Gyulhyun Weir station during the flood event in 2010. Based on this information, stage-discharge curve has been developed and its reliability has been tested for flood event in 2011.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.172-178
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• 2006

There has been tremendous increase of disaster related damages since 1990's. Especially flood occurred in summer season highly populated area has led to demolish a lot of facilities and buildings within a short time period. This is to figure out the way to predict the vulnerable flood inundation area by past records of inundation and and geographic information available. The comparative study on 1998 and 1999 flood inundation area in Munsan and Gokneung river shows that 5 degree of slope and 10 m elevation level are dividing index to draw the vulnerable area. This study is to suggest the relatively easy method to predict flood vulnerable area and to apply the results to prepare for protecting the facilities and the people with other thematic geographic database.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.573-583
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• 2013

Construction of large-scale structures such as dams would be suggested actively to cope with change of flood characteristics caused by climate change. However, due to environmental, economic and political issues, dams are not ideally constructed. Thus flood damage reduction planning projects would get started including washland or detention pond for sharing the flood in basin. The washland made artificially by human being is an area of floodplain surrounded by bank to be intentionally inundated by overflowing through overflow structure adjacent to main channel during flood season. Flood reduction capacity at just downstream of each washland could be affected by type, length, and crest elevation of overflow structure in addition to shape of design hydrograph, storage volume of washland, etc.. In this study flood reduction effects of washland are estimated for overflow weir type and gate type to compare the results of flood reduction respectively subjected to given hydrograph in sample site, the Cheongmicheon stream. It has been shown that even if gate type at overflow structure could yield more flood reduction than overflow weir type, economic aspect such as initial cost, operation cost and maintenance cost should be considered to select the type of overflow structure because flood reduction rate by gate type could not be significant value from engineering point of view.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.4
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• pp.85-90
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• 2005

Inundation of Transformer Vault breaks out every summer season in low-tying downtown and low-tying shore by localized heavy rain, typhoon and tidal wave. In case inundation of Transformer Vault, it occurs a great economic loss owing to recovery time and events of electric shock occur by inundation electrical facility. So we need installation plan of Transformer Vault in common flood area for preventing from economic loss and equipment events. Therefore we research distribution of 22.9[kV] Transformer Vault in common flood of the country and analyze field condition about flood protection plan. And we analyze regulation or law relating to the flood protection counterplan of US, England, Australia. This paper will be used to present a reform proposal of electrical related law about flood protection of existing Transformer Vault. Also we present considering facts at the time Transformer Vault installation in common flood area.

• Journal of Korea Water Resources Association
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• v.50 no.6
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• pp.407-418
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• 2017

Due to geographical features of being close to DPRK (Democratic People's Republic of Korea), the Imjin River basin has difficulties in hydrological observation, and is vulnerable to unexpected flood occurrence. As a countermeasure, Gunnam Flood Control Reservoir construction was planned in 2005. Despite such a structural measure, damages by DPRK's illegal release continues to occur. Futhermore the Imjin River's flow has been decreased due to the effect of continuous drought in the Korean Peninsula since 2012 and DPRK's unilateral storage of water. A new operation method is derived for the Gunnam Flood Control Reservoir in order to cope with drought damages on the Imjin River basin and to ensure efficient response time upon flooding. The operation method maintaining Gunnam Flood Control Reservoir's water level by raising from EL.23.0 m to EL.31.0 m during the flood season for securing reservoir capacity enables to secure additional $14,000,000m^3$ water compared to the existing operation methods. The operation method to store inflow by controlling release to $250m^3/s$ in the early stage of flood has increased 2.66% on average in terms of detention effect of reservoir compared to the existing operation methods. The method enables to secure 19 hours to prepare flood compared to the existing methods.

• Proceedings of the KSRS Conference
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• v.1
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• pp.455-458
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• 2006

Stretching on the coastline of 70 km, the Tam Giang - Cau Hai Lagoon plays a very important role for the coastal ecology and socio-economic development of Hue region where was Vietnam's Ancient Kingdom Capital and recognized as a World's Cultural Heritage. Recently, coastal hazard in the lagoon have occurred seriously such as inlet movement and fill up, coastal erosion, flood and inundation, etc. These hazards have impacted on lagoon environment, resources, ecosystems, socio-economic and sustainable development of this coastal area. This paper present a case study using remote sensing data in combination with ground survey for monitoring the coastal hazards in Tam Giang - Cau Hai lagoon in recent decades. Analysis results find that during its natural evolution, the lagoon has been being in three situations of only one, two and three inlets. When inlets opened or displaced, coastal erosion have occurred seriously toward new balance condition. Flood and inundation occurs every rainy season in lowland plain around lagoon. The historical flood happened in early of November 1999 with six days long, created very terrible damages for Thua Thien Hue province. Remote sensing data with capability of regular update, large area coverage is effective provide real-time and continuous information for coastal hazards monitoring.

• Journal of Korean Society of societal Security
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• v.1 no.4
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• pp.51-56
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• 2008

Because of our country's climate that has the 50% of the annual precipitation in summer, annually a lot of bridges on the roads are broken in this season. So, we need an accelerated bridge construction method that complete to repair the roads. This paper introduces the Hangae 2 bridge, prefabricated bridge using full depth precast deck panels and new types of PSC girders. The Hangae 2 bridge located in lnje-gun, kangwon-do. This is a good example of the accelerated bridge construction method for recovery of flood damaged road. The PSC girder bridge system introduced in this paper is a rapid construction method for bridge that can reduce the term of works over 50%.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2003.10a
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• pp.1-21
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• 2003

I introduce the Flexible Dam Operation (FDO) and some of sediment control techniques In dams which are implemented as trials to avoid or reduce environmental impact of dams on the downstream reaches. The FDO is a dam management method to improve river environment in the downstream reaches by means of the flushing flow, the maintenance flow and so on utilizing a vacant portion of capacity for flood control without interrupting prime flood control function during the rainy/typhoon season. It Is suggested by the guideline of the FDO that EDO should be implemented regularly after the trial for about three years. The basic conception of the FDO is described here. The example of excavation of deposited sediments in check dams and placement of sand ana gravel immediately downstream of the dams and the example of coordinated sediment flushing are described as some of sediment control techniques in dams. Now they are at the stage of experiment and trial. Therefore, it is important to increase examples and establish the technical methodology and the environmental evaluation method for them.