• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.325-331
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• 2016

This research developed a flood fragility curve of bridges considering the debris impacts. Damage and failures of civil infrastructure due to natural disasters can cause casualties as well as social and economic losses. Fragility analysis is an effective tool to help better understand the vulnerability of a structure to possible extreme events, such as earthquakes and floods. In particular, flood-induced failures of bridges are relatively common in Korea, because of the mountainous regions and summer concentrated rainfall. The main failure reasons during floods are reported to be debris impact and scour; however, research regarding debris impacts is considered challenging due to various uncertainties that affect the failure probability. This study introduces a fragility analysis methodology for evaluating the structural vulnerability due to debris impacts during floods. The proposed method describes how the essential components in fragility analysis are considered, including limit-state function, intensity measure of the debris impact, and finite element model. A numerical example of the proposed fragility analysis is presented using a bridge pier system under a debris impact.

• Journal of Korean Society on Water Environment
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• v.29 no.6
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• pp.754-761
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• 2013

Urban floods are usually caused by the lack of drainage capacity. Hence, sewer capacity expansion methodology by replacing small pipes with bigger ones is primarily applied as a flood control measure. However, this approach is often unreasonable because of the costs and time involved. Thus, the installation of underground rainwater storage tanks with the two advantages of flood control and water conservation is proposed. This study compared the effectiveness of flood control by both the sewer expansion methodology and rainwater storage tanks using the Storm Water Management Model. Three cases were simulated in this study. The first case analyzed flood reduction by the storm sewer expansion methodology. The simulation results indicate that the overflow volume from manholes was reduced by 49% with this methodology. The second case analyzed flood reduction by installation of rainwater storage tanks. The simulation results indicate that the overflow volume was reduced by 62%. However, these two cases could not prevent urban floods completely. Hence, the third case analyzed the joint application of the storm sewer expansion methodology and rainwater storage tanks. In this simulation, flooding did not occur. Consequently, the results of this study clearly show that underground rainwater storage tanks are more effective for flood control than capacity expansion of storm sewer. Furthermore, the joint application of these two flood control measures is more effective than their separate application.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.695-708
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• 1998

Recently, it seems increasing trends that the design floods on the middle and small scale of urban regions and natural basins are evaluated with introducing to the concept of the critical storm duration. However the study of the critical storm duration is not sufficient and especially on the natural basins, it rarely performed. therefore in this study, estimated the critical storm duration and peak discharge according to the rainfall distribution type, the position of peak rainfall intensity, and the frequency on the natural basins were evaluated using Clark model and the influence of each factors on the design floods was analyzed with sensitivity analysis on the parameters of the model.

• Journal of architectural history
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• v.28 no.6
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• pp.55-65
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• 2019

Ganggyeong, a city which is located at riverside of Geum River, played a role to connect the inland cities and the coastal cities through the Geum river waterway. In Chosun dynasty, Ganggyeong was one of the three major markets in Korea, and at the same time, it was one of the two river docks in Korea. However, after the railway was installed in Korea, railroad was more important than waterway in transporting logistics and in 1911 Honam railroad and Ganggyeong railway station was installed. Thus it was necessary to reorganize urban structure of Ganggyeong city from the traditional river-dock city to modern railroad city. In addition, urban infrastructure to prevent flood damage was needed because Ganggyeong suffered from floods and water shortages every year. Therefore, between 1910s and 1930s large-scale social infrastructures including road, water and sewage system, river bank, floodgate was constructed not only to revitalize the declining city but also to prevent flood damage and water shortages that hinder urban development. The installation of urban infrastructure has enabled the urban expansion and development of Ganggyeong city, and it is still served as a basic urban structure.

• KIEAE Journal
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• v.14 no.3
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• pp.15-21
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• 2014

In this study, we developed a modular rainwater infiltration system that can be applied for general purposes in urban areas to prepare for localized heavy rain caused by climatic change. This study also analyzed the system's effects on reducing runoff. An analysis of the system's effects on reducing runoff based on rainfall data and monitoring data obtained between September 2012 and December 2013 after the system was installed showed that approximately 20~22% of the runoff overflowed from the infiltration facility. Also, an analysis of the runoff that occurred during the monsoon season showed that 25% of the runoff overflowed through the storm sewer system of the urban area. These results show that the rainwater overflows after infiltrating the detention facility installed in the area during high-intensity rainfall of 100mm or higher or when precipitation is 100mm for 3~4 days without the prior rainfall. According to precipitation forecasts, torrential rainfall is becoming increasingly prevalent in Korea which is increasing the risk of floods. Therefore, the standards for storm sewer systems should be raised when planning and redeveloping urban areas, and not only should centralized facilities including sewer systems and rainwater pump facilities be increased, but a comprehensive plan should also be established for the water cycle of urban areas. This study indicates that decentralized rainwater management can be effective in an urban area and also indicates that the extended application of rainwater infiltration systems can offer eco-friendly urban development.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.139-145
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• 2010

Recently, close-to-nature stream improvement works have been carried out in urban streams, where eco-friendly bank revetment methods have been adopted. These bank revetment methods are vulnerable to be damaged or washed away by floods compared to the traditional methods which use concrete materials. Damage analysis methods on the urban streams by the floods of severe rain storm are presented. The analysis methods are the graph-using method and the grid method, which are derived from the survey results at Gwangju stream. Damage analysis grid which is intersected velocity grid and material strength grid is the highest correlation with the damage survey grid. The biggest damage on the bank revetments have been occurred around the crossing structures. Big damages have also been occurred in the connection of low water revetment and the terrace land, and around the structures in the terrace land of the stream.

• Journal of the Korean association of regional geographers
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• v.14 no.2
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• pp.105-113
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• 2008

The purpose of this paper is to analyze the influences of extreme flood on urban stream's habitat environment at Shincheon stream in Daegu. In case of Shincheon stream, as any extreme floods have not flowed over the artificial bank, an extreme flood have an effects on inner part of confined channel. To make riparian park along Shincheon channel, Concrete and rubber weirs are constructed. These weirs interrupted flow of running water as obstacles during extreme flood, and running water moved aside into and destructed banks of lower-flow-channel. In reach of no weir, as all small-scale topographic bedforms were eliminated, habitat environment of river ecosystem was simplified, and biodiversity of river ecosystem was decreased. As simplified riverbed become irregular bedforms through frequent small-scale-floods, river ecosystem will become vigorous.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1209-1213
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• 2005

It reflects well feature of slope that is characteristic of city river basin of Pusan local. Process various hydrological datas and basin details datas which is collected through basin basis data. weather satellite equipment(EMS-DEU) and automatic water level equipment(AWS-DEU) and use as basin input data of ILLUDAS model, SWMM model and HEC-HMS model In order to examine outflow feature of experiment basin and then use in reservoir design of experiment basin through calibration and verification about HEC-HMS model. Inserted design rainfall for 30 years that is design criteria of creek into HEC-HMS model and then calculated design floods according to change aspect of the impermeable rate. Capacity of reservoir was determined on the outflow mass curve. Designed imagination reservoir(volume $54,000m^3$) at last outlet upper stream of experiment basin, after designing reservoir. It could be confirmed that the peak flow was reduced resulting from examining outflow aspect. Designing reservoir must decrease outflow of urban areas.

• Journal of the Korean Professional Engineers Association
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• v.43 no.6
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• pp.31-34
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• 2010

Recently, due to localized heavy rain and flash floods in urban areas is becoming more frequent flood damage. To prevent flood inundation damage, to formulate the diverse directions in connection with the drainage system of buildings, roads, sewerage, pump stations, detention (retention) pond, and streams is very important. In addition, it is important for the uniform design criteria, the consistent of hydrologic and hydraulic analysis method, and a flood disaster mitigation systems connected with structural and nonstructural measures. To accomplish this, the method such as installation of storage facilities, infiltration facilities, and underground water tank, the optimal size of the design gutter and grate of the road, ensure the capacity of pumping stations, and the installation of a flood control channel into the deep underground requires comprehensive measures dimension in urban areas.

• Journal of architectural history
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• v.31 no.2
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• pp.51-65
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• 2022

Seoju is one of the nine weeks of the ancient period, and according to literature records, the construction of Seojuseong Fortress has a long history of 2573. This is the land of Oseongtong-gu, a political and military hub, and flood disasters have frequently led to frequent reconstruction of fortresses. In particular, it is also an important place to show that the function of the fortress is defensive and has a function of preventing floods. This study analyzed the shape of Seojuseong Fortress and the characteristics of urban spaces in the Myeongcheong period through excavation data and literature data.