• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.257-266
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• 2021

Urban areas can often suffer flood damage because of the more frequent catastrophic rainfall events from climate change. Flood mitigation measures consist of (1) structural and (2) non-structural measures. In this study, the proposed method focused on operating an urban drainage system among non-structural measures. The combined inland-river operation technique estimates the inflow of pump stations based on the water level obtained from a preselected monitoring point, and the pump station expels the stored rainwater to the riverside based on those estimates. In this study, the proposed method was applied to the Mokgam drainage watershed, where catastrophic rainfall events occurred (i.e., 2010- and 2011-years), and severe flood damage was recorded in Seoul. Using the proposed method, the efficiency of flood reduction from the two rainfall events was reduced by 34.9 % and 54.4 %, respectively, compared to the current operation method. Thus, the proposed method can minimize the flood damage in the Mokgam drainage watershed by reserving the additional storage space of a reservoir. In addition, flooding from catastrophic rainfall can be prevented, and citizens' lives and property in urban areas can be protected.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.13-26
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• 2015

Many urban areas in Korea suffer from repeated flood damage during intensive rainfall due to an increase in impervious areas caused by rapid urbanization and deteriorating sewage systems. A centralized stormwater management system has caused severe flood damage in an area that has proven unable to accommodate recent climate change and a rise in precipitation. Most flooding prevention projects that have been recently implemented focus on increasing drainage system capacity by expanding the size of sewer pipes and adding pumping stations in downstream areas. However, such measures fail to provide sustainable solutions since they cannot solve fundamental problems to reduce surface runoff caused by urbanization across the watershed. A decentralized stormwater management system is needed that can minimize surface runoff and maximize localized retention capacity, while maintaining the existing drainage systems. This study proposes a stormwater management corridor for the flood-prone watershed in the city of Dongducheon. The corridor would connect the upstream, midstream, and downstream zones using various methods for reducing stormwater runoff. The research analyzed surface runoff patterns generated across the watershed using the Modified Rational Method considering the natural topography, land cover, and soil characteristics of each sub-watershed, as well as the urban fabric and land use. The expected effects of the design were verified by the retainable volume of stormwater runoff as based on the design application. The results suggest that an open space network serve as an urban green infrastructure, potentially expanding the functional and scenic values of the landscape. This method is more sustainable and effective than an engineering-based one, and can be applied to sustainable planning and management in flood-prone urban areas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.79-88
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• 2006

In this study, a methodology is developed for flood runoff analysis considering the interaction between interior floodplain and channel. Riparian lowland is modeled as storage areas by HEC-RAS and is connected with main channel through gravity drainage structure and pumping stations. As a result, we were able to compute the difference between runoff into the interior floodplain and delayed runoff to main channel from interior floodplain. This allowed us to compute the storage change in the interior floodplain and corresponding inundation areas. Furthermore, the levee is modeled as a lateral structure and the flood from the main channel to interior floodplain is modeled by installing a weir on top of it. In addition, levee breach is also modeled so that flooding from main channel to interior floodplain can be considered. Computed flooding depth in the storage areas are compared with elevation to identify the inundated areas and flood maps can then be produced for a desired time or for the extent of flooding given a flooding depth. Output from this modeling effort can provide many useful information for flood planning such as flow depth in main channel, flooding depth and area in interior floodplain. The method was applied to Sapgyo river basin and the comparison with observed flood events showed that it can reproduce the observation fairly well, hence proving the utility of the method.

• Journal of the Korean Geographical Society
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• v.49 no.5
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• pp.639-655
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• 2014

Uvala is one of the geographic features which have been discussed very actively in the field of Karst geomorphology, but most researches in Korea have been staying at the level which uvala were discussed from the viewpoint of the Karst cycle. In this study, the geomorphological characteristics of Kwangduck-ri Uvala will be identified on the basis of the various definitions, and the irrigation systems which have been developed during 250 years will be analysed using a number of data, such as interviews, statistical data, maps, air-photos, especially topographical analysis from GIS. It is concluded that the site of Kwangduck-ri Uvala would have shown the genuine history to adapt and overcome the obstacles of harsh karst environment and to make the stable agricultural and irrigation system in the high plateau karst area.

• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.865-870
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• 2005

Because there are only a limited number of means of action that are available for the master to pursue in the event of flooding, onboard decision support system has been required. The majority of systems activated during a flooding emergency (such as watertight and semi-watertight doors, bulkhead valves, dewatering pumps etc.) almost exclusively aim to restore a sufficiently high level of subdivision to prevent flooding from spreading through the ship. Even though assuming the flooding scenario is not catastrophic, the use of ballast tanks can be an additional and very effective tool to ensure both prevention of flooding spreading and also improve ship stability. This paper describes an optimization algorithm devised to choose the set of ballast tanks that should be filled in order to achieve an optimal response to a flooding accident.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.31-31
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• 2011

해마다 반복되는 수해를 대비하여 배수펌프장을 설치하고, 취수보를 철거하는 방법으로 수해예방시스템을 고도화 시키고 있지만, 증가하는 홍수량에 대한 대비책으로는 역부족이다. 따라서, 홍수 피해에 대한 선제적 대응방안으로 강변저류지를 설치하여 상습 침수구역에 대한 대비가 진행되고 있다. 강변저류지 설치를 통해 유역의 홍수량을 분담하고 인접지역의 침수피해를 예방하는 역할을 기대할 수 있다. 국내에서도 영월군의 상습침수구역에 대한 대비책 중 하나로 국토해양부 및 강원도가 함께 영월강변저류지 조성공사를 추진하고 있다. 영월군은 지난 2002년과 2003년에 태풍 '루사'와 '매미'로 인해 심각한 피해를 입었으며, 2006년 집중호우시에도 현재 저류지 예정지역인 방절리 일대와 영월읍 시가지, 북쌍리 등이 대규모로 침수피해를 입은 바 있다. 해당 저류지의 총 넓이는 68만 8천 $m^2$로 물 290만 $m^3$을 가두어 둘 수 있는 규모이다. 하지만, 영월 강변저류지의 저류용량이 290만 $m^3$에 불과해 홍수예방 효과가 미흡하다는 지적이 잇따르고 있다. 따라서, 적절한 수문운영을 통해 홍수저감량과 저류효과를 증대시키는 홍수예방 방안을 제안하고자 한다. 본 연구에서는 유전알고리즘의 적용을 통하여 강변저류지에 설치된 수문의 운영 방법을 개선함으로써 홍수저감량을 최대화하고자 하였다. 수리 수문학적 모형인 HEC-RAS, HEC-I 모형을 연계 운용하여 평창강 유역을 대상으로 수문분석, 홍수유출량 분석, 하류 하천의 홍수영향 분석 결과를 도출하였다. 강변저류지 설치로 인하여 저류지 직하류부를 기준으로 약 $131\;m^3/s$의 첨두홍수량 저감 효과가 발생하는 것으로 검토되었지만, 본 연구에서 제안된 최적화 기법이 적용된 수문운영 방법을 병행하여 운영한다면 추가적으로 $24\;m^3/s$를 저감하는 효과를 얻을 수 있다. 효율적으로 저류지를 운영하여 홍수피해를 사전에 방지하고 나아가 다른 저류지 유역에도 본 연구를 적용하여 홍수피해를 줄이고 합리적으로 용수를 이용하는데 기여할 수 있을 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1089-1093
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• 2007

서낙동강은 유역면적이 $304.1\;km^2$이고, 유로연장이 18.5 km로서 유역형상이 방사상과 우상의 혼합상으로 비교적 구형을 이루고 있으며, 유역의 평균폭은 동서방향으로 $17{\sim}20\;km$, 남북방향으로는 약 18 km정도이다. 연평균강수량은 1,349 mm이다. 서낙동강은 상류에는 대저수문, 하류에는 녹산수문이 위치하고 있으며, 이와 같은 수문들에 의하여 하천의 유량이 조절되는 호소형 하천이다. 홍수시 유역의 60% 이상이 침수되는 수해 상습지구에 해당되며, 대저수문과 녹산수문에 의해 조절되고 있어 자연적인 하천흐름이 원활하지 않은 정체수역이다. 따라서 장기간 오염물질이 퇴적되고 있으며, 이로 말미암아 수질오염이 매우 심한 곳이기도 하다. 따라서 수문에 의해 조절되는 하천에서는 적절한 하천유지유량의 확보는 물론이고, 하천의 수질악화를 고려한 하천운영 기법의 도입이 절실히 요구되고 있다. 특히, 최근에 화두가 되고 있는 유역의 수량과 수질의 통합 관리를 실현하기 위해서도 하천의 수질뿐만 아니라 어류의 서식환경까지도 고려한 수문 운영기술의 개발이 요구된다. 서낙동강의 수문 개방시기에 맞춰 수질분석을 한 뒤 개방 전, 후의 수질결과를 비교 분석해야 한다. 이와 함께 낙동강 본류의 수질도 함께 분석하여 서낙동강 수질 개선에 필요한 수문운영 방안을 도출해야한다. 수문운영자와 하천수 이용자들은 갈수기 하천 수질악화, 오염물질 누출사고 등이 발생할 때 하천 수질개선 효과를 극대화하기 위해서는 보다 많은 유입량을 취수하여 서낙동강에 통수해야 하는데, 이는 향후 녹산수문의 배수펌프장을 활용하면 가능할 수 있을 것으로 판단되며, 이를 위해서는 낙동강 하구언의 수량감소 문제와 방류량 증가에 따른 녹산수문 하류측의 외해에 대한 환경영향도 반드시 고려되어야 한다. 본 연구에서는 이와 같은 서낙동강의 수질관리 방안을 도출하기 위하여 수문 유입량 및 방류량 변화에 따른 하천수질 변화를 측정 자료 분석을 통해 수행하였다. 본 연구결과는 향후 동적 수질모형 연구에 활용할 수 있을 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.1
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• pp.29-39
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• 2018

In this study, the applicabilities of flood risk indices using FVI from IPCC, PSR method from OECD, and DPSIR method from EEA, were analyzed. Normalized values of daily maximum rainfall, hourly maximum rainfall, ten minute maximum rainfall, annual precipitation, total days of heavy rainfall (more than 80mm/day), density of population, density of asset, DEM, road statistics, river maintenance ratio, reservoir capacity, supply ratio of water supply and sewerage, and pumping capacity were constructed from 2000 to 2015 for nationwide 113 watersheds, to estimate flood risk indices. The estimated indices were compared to 4 different types of flood damage such as the number of casualties, damage area, the amount of flood damage, and flood frequency. The relationships between flood indices and different flood damage types demonstrated that the flood index using the PSR method shows better results for the amount of flood damage, the number of casualties and damage area, and the flood index using the DPSIR method shows better results for flood frequency.

• Journal of Korea Water Resources Association
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• v.48 no.10
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• pp.845-855
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• 2015

Studies of optimizing pump operation in water distribution networks (WDN) are receiving spotlight in recent days. However, the water networks are quite complex including thousands of or even tens of thousands of nodes and pipes, thus simulation time is an issue. In some cases, implementing a computer model for pump operation decisions is restrictive due to intensive computation time. To that end, it is necessary to reduce the simulation time of water networks by simplifying the network layout. In this study, WDN skeletonization approaches were suggested and applied to a real water transmission network in South Korea. In skeletonizing the original network, it was constrained to match the water pressure and water age in the same junction locations to maintain the hydraulic and water quality characteristics in the skeletonized network. Using the skeletonization approaches suggested in this study, it is expected to reduce the simulation time of WDN and apply for developing a computer module of WDN real-time optimal operation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.75-80
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• 2005

Because there are only a limited number of means of action that are available for the master to pursue in the event of flooding, onboard decision support system has been required The majority of systems activated during a flooding emergency (such as watertight and semi-watertight doors, bulkhead valves, dewatering pumps etc.) almost exclusively aim to restore a sufficiently high level of subdivision to prevent flooding from spreading through the ship. Even though assuming the flooding scenario is not catastrophic, the use of ballast tanks can be an additional and very effective tool to ensure both prevention of flooding spreading and also improve ship stability. This paper describes an optimization algorithm devised to choose the set of ballast tanks that should be filled in order to achieve an optimal response to a flooding accident.