• Title/Summary/Keyword: flood current

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Flood Simulation by using High Quality Geo-spatial Information (고품질 지형공간정보를 이용한 홍수 시뮬레이션)

  • Lee, Hyun-Jik;Hong, Sung-Hwan
    • Journal of Korean Society for Geospatial Information Science
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    • v.18 no.3
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    • pp.97-104
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    • 2010
  • The important factors in a flood simulation are hydrologic data (such as the rainfall and intensity), a threedimensional terrain model, and the hydrologic inundation calculation matrix. Should any of these factors lack accuracy, flood prediction data becomes unreliable and imprecise. The three-dimensional terrain model is constructed based on existing digital maps, current map updates, and airborne LiDAR data. This research analyzes and offers ways to improve the model's accuracy by comparing flood weakness areas selected according to the existing data on flood locations and design frequency.

The Development of Flood Protection System for Pad Transformer using Pneumatic Pressure (공기압을 이용한 패드 변압기 침수방지용 장치 개발에 관한 연구)

  • Kim, Gi-Hyun;Lee, Sang-Ick;Bae, Seok-Myung;Jung, Chan-Oong;Lee, Jae-Yong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.1
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    • pp.90-94
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    • 2009
  • The inundation of substation and ground power equipment breaks out every summer season in low-lying downtown and low-lying shore by localized heavy rain, typhoon and tidal wave. For diminishing flood damage of electrical equipment in the root, flood protection system which is used the basic frame of Pad transformer is developed using pneumatic pressure. This system is established on pressure generator equipment and sensor of flooded level operates at flooding occurrence and is maintained a shutting tightly structure. The system is able to protect indraft water in Pad Transformer and supply the electricity at emergency(flooding). And we tested safety for insulation resistance at flooding and applying an electrical current. We estimate that loss cost which is caused by with flooding and the power failure will be diminished if it is addition to advances the reliability evaluation by setting an example.

Reservoir Routing in Estuary Lake Influenced by Tidal Effects (조석 영향을 받는 하구호에서의 저수지추적)

  • Kim, Joo-Young;Lee, Jong-Kyu;Yoon, Kwang-Seok;Kim, Han-Sup
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.722-725
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    • 2007
  • Geum River Estuary Barrage is very important for the irrigation, municipal and industrial uses in the cities of Gunsan, Iksan and Jeonju. The Geum River Control Office has a flood forecasting system; however, the current system does not consider the backwater effects. As a result, it is very difficult to give correct flood information, and it is difficult to accurately assess the water resource supply and saltwater invasion into freshwater, as frequently occurs due to over-discharge during floods. In this study, we investigate the flood forecasting system for the Geum River reach influenced by the estuary barrage. The current system cannot consider the backwater effect because the estuary barrage blocks the end of the river. We calculated the discharge from the tide lock and evaluated the inside water level of the estuary barrage during floods. The results show that the calculation agrees well with the observed data at the river stage stations in the Geum River. The results also show that this program is a reasonable substitute for the current system.

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Flow Characteristics of Gamcheon Harbour (감천항의 해수유동 특성)

  • 김기철;김재중;장필훈
    • Journal of Korean Port Research
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    • v.13 no.2
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    • pp.409-418
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    • 1999
  • Gamcheon Bay has complicated and unique flow pattern which is affected by topography characteristics of a semi-closed bay and warm water discharge from the power plant located at the bay. It is very important to consider warm water discharge with tidal period and wind effects, which are mainly acting on the surface flow patterns in Gamcheon Bay. The results of observation show as follows; i) Because Gamcheon bay has much elongated shape to the north-south direction and narrow entrance with two separated breakwaters, the flow is very weak inside the bay. ii) The main flow path is at the west side of the bay. The direction of flood current is northward along the west side of the bay and the direction of ebb current is southward along the west side of the bay. The southward direction of warm water discharge has curved to the west side of the bay. iii)At the period of flood current for neap tide, the flow direction is southward in the bay, which is thought by the effects of warm water discharge. But at the bottom layer, the effects of tidal current reached to the middle of the bay, and showed features like eddy. iv) The wind effect is very strong, especially, prominent in the west and east side of the bay.

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Spread Patterns of Thermal Effluent Discharged From Young-Kwang Nuclear Power Plant Using Remote Sensing Data

  • Han J. G.;Yeon Y. K.;Chi K. H.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.331-335
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    • 2004
  • This study is focused to analyze the movement of thermal effluent dischargeed from nuclear power plant by season, ebb and flow, and before and after foundation of tide embankment using thermal infrared band image of 28 scenes observed from Landsat from 1987 to 2004, which is the early stage of operation of young-kwang nuclear power plant. In diffusion of thermal effluent discharge by seasons, spring and summer is spreading further than autumn and winter. It is considered to distribute widely mixed with thermal effluent discharge and hot water, which is distributed naturally along the seaside. It is known the fact that tidal currents control the direction of diffusion of thermal effluent discharge by the change of ebb and flow. Namely, it is distributed widely on the Southwest direction along the seaside by tidal currents when ebb and, it is moved widely on the Northeast direction along the seaside by tidal current when flood. However, in the early stage of flood current, the mainstream of thermal effluent discharge is spread on Southwest direction and, the direction is changed on North­east way when the latter period of flood current. Similarly, in the early stage of ebb current, the mainstream of thermal effluent discharge is spread on Northeast direction and, the direction is changed on Southwest direction when the latter period of ebb current. As the result of comparing to the diffusion pattern of thermal effluent discharge before and after the foundation of seawall, discharged thermal effluent from the drain of plant by the foundation of dike is shown as curved circle pattern on Northeast to West direction from the ending portion of the seawall.

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Hydrological Stability Analysis of the Existing Soyanggang Multi-Purpose Dam (소양강 다목적댐의 수문학적 안정성 검토)

  • 고석구;신용노
    • Water for future
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    • v.28 no.3
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    • pp.187-195
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    • 1995
  • This study aims at suggesting an alternative to improve current capacity of flood control for the existing Soyanggang multi-purpose dam which was constructed 20 years ago as a largest dam in Korea. The newly estimated value of the probable maximum precipitation(PMP) is 760.0 mm which is based on the hydrometeorological method. The peak inflow of 1000 years return period at the time of construction was 13,500$m^3$/s. However, the newly estimated peak inflow of the PMF is 18,100$m^3$/s which is 1.34 times bigger than the original one. In order to adopt the newly estimated PMF as a design flood, following four alternatives were compared; (1) allocation of more flood control space by lowering the normal high water level, (2) construction of a new spillway in addition to the existing one, (3) raising the existing dam crest, (4) construction of a new dam which has relevant flood control storage at the upstream of the Soyanggang multipurpose dam. The preliminary evaluation of these alternatives resulted in that the second alternative is most economical and feasible. So as to stably cope with the newly estimated PMF by meeting all the current functions of the multi-purpose dam, a detailed study of an additional spillway tunnel has to be followed.

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A Study on Urban Flood Vulnerability Assessment Considering Social Impact (사회적 평가 지표를 반영한 도시 홍수취약성 평가)

  • Lee, Gyu Min;Choi, Jin Won;Jun, Kyung Soo
    • Land and Housing Review
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    • v.11 no.1
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    • pp.109-116
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    • 2020
  • This study aims to establish an approach to assess urban flood vulnerability by identifying social characteristics such as the road transportation and the vulnerable groups. Assessment procedures comprise three steps as: (1) composing the assessment criteria to reflect the urban characteristics; (2) calculating the weight; and (3) evaluating the vulnerability. The criteria were adopted by Delphi survey technique. Four criteria as land cover, residents, vulnerable areas, and disaster response were adopted in the current study. To determine the weight set of criteria, subjective and objective methods were combined. The weight set was determined using the combined method which reflects the Delphi method and Entropy analysis. In the process of data-based construction, GIS tools wwere used to extract administrative unit materials such as land cover, road status, and slope. Data on population and other social criteria were collected through the National Statistical Office and the Seoul Metropolitan statistical data. TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) technique, which uses materials from cell units in order to rank the closest distance to the best case and the farthest distance from the worst case by calculating the distances to the area of assessment, was applied to assess. The study area was the Dorimcheon basin, a flood special treatment area of Seoul city. The results from the current study indicates that the established urban flood vulnerability assessment approach is able to predict the inherent vulnerable factors in urban regions and to propose the area of priority control.

Application of Flood Vulnerability Index for analyzing safety change of levee according to climate change (기후변화에 따른 제방의 안전성 영향 분석을 위한 제방홍수취약성지수의 적용)

  • Lee, Hoo Sang;Lee, Jae Joon
    • Journal of Korea Water Resources Association
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    • v.51 no.4
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    • pp.293-299
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    • 2018
  • In this study, a new technique for evaluating the flood vulnerability of river banks is proposed. For this purpose, flood quantities of the basin were estimated based on the future climate change scenarios and the infiltration stability was evaluated by analyzing the infiltration behavior using SEEP/W which is a 2D groundwater infiltration model of the levee. The size of the river levee was investigated. The size of river levee was investigated by selecting the target area. The safety factor of the levee was analyzed considering the current flood level of the levee and the flood level considering the climate change. The factor needed to analyze the levee vulnerability was derived. We analyzed the vulnerability of the levee considering the change of the levee level according to the climate change scenarios. Levee Flood Vulnerability Index (LFVI) were used to evaluate the vulnerability of the levee.

Hydrological Stability Analysis of the Existing Soyanggang Multipurpose Dam

  • Ko, Seok-Ku;Shin, Yong-Lo
    • Korean Journal of Hydrosciences
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    • v.7
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    • pp.37-49
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    • 1996
  • This study aims at suggesting an alternative to improve flood controling capacity according to the cument design criteria for the existing Soyanggang Multi-purpose Dam which was constructed 20 years ago as the largest dam in Korea. The peak inflow of the adopted probable maximum flood (PMF) at the time of construction was 13,500 $m^3$/s. However, the newly estimated peak inflow of the PMF is 18,000 $m^3$/s which is 1.34 times bigger than the original one. This is considered to be due to the accumulation of the reliable flood and storm event records after construction, and due to the increasing tendency of the local flood peaks according to the influence of world-wide weather change. The new estimation of the probable maximum precipitation (PMP) was based on the hydro-meteorological method suggested by the guideline of the World Meteorological Organization (WMO). The unit hydrograph which was applied for the estimation of PMF was derived through linear programming algorithm by minimizing the sum of absolute deviations of the calculated and recorded flood hydrographs. In order to adopt the newly estimated PMF as a design flood, following four alternatives were compared : (1) allocation of more flood control space by lowering the normal high water level, (2) construction of a new spillway in addition to the existing spillway, (3) construction of a new dam which has relevant flood control storage at the upstream of the Soyanggang dam, (4) raising the existing dam crest. The preliminary evaluation of these alternatives resulted in that the second alternative is most economic and feasible. So as to stably cope with the newly estimated PMF by meeting all the current functions of the multipurpose dam, a detailed study of an additional spillway tunnel has to be followed.

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An Awareness and Needs Analysis for the Flood Disaster School Safety Education Execution - Focusing on the awareness of secondary school students and teachers in Daegu - (수재해 학교 안전교육 실행에 대한 인식 및 요구 분석 - 대구지역 중·고등학교 학생과 교사의 인식을 중심으로 -)

  • Ahn, Young-Mi;Hong, Won-Hwa;Lee, Hye-Kyoung;Bae, Young-Hoon
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.4
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    • pp.13-22
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    • 2020
  • Recent abnormal climate has increased the frequent of heavy rains and floods, and over 100 people have been killed in the last decade caused by these. In the midst of severe flood disasters, safety education to learn how to respond and evacuate them has become important. The purpose of this study was to analyze the needs and effective education types for the flood disaster school safety education. This study shows Analysis the current state of school safety education based on the 7 standards of school safety education, especially in disaster safety categories through the survey of secondary school teachers and students. And a desirable form of flood safety education was derived by analysis of awareness of flood disaster safety education and their educational needs. More than 70% of teachers and students hoped for a experience-based flood disaster safety education, they wanted to learn once a year, one hour from a safety education specialist in experience facilities. As for the contents of the training, they wanted to experience evacuation in the event of flood disaster, and also wanted education related to survival swimming. The most necessary thing for the establishment of experience-based disaster safety education was the expansion of experience facilities.