• Title/Summary/Keyword: flood management

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Improvement of National Risk Alarm 4-Stage Criteria for Flood Disaster (홍수재난 대응을 위한 국가위기경보 4단계 설정기준 개선)

  • Lee, Sookyong;Park, Jae-Woo;Oh, Eun-Ho
    • The Journal of the Korea Contents Association
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    • v.18 no.3
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    • pp.369-377
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    • 2018
  • EAP, which is operated on the frame of Risk Alarm 4-stage of National Risk Management Guideline, is a critical method in order to promptly respond to disasters. Korea Flood Control Office issues major and moderate flood alarm at each river station by respectively 50% and 70% of design flood discharge in terms of watermark or sea level, however, the criteria deciding major and moderate floods are vague for field managers to control the disaster situations. On the other hand, Japan and USA use river water level as a main criterion in order to classify the stage of flood disaster, which is higher design flood level than Korea. Thus, the authors analyzed domestic and oversea EAP guidelines and suggested improved criteria showing easy display method and raising the criteria of flood level for reflecting more effective action plans through testing a simulation training on the test-bed.

A Study on the Behavior of Floating Debris in a Flood Control Dam Using the Lagrangian Particle Traking Method (라그랑지안 입자 추적기법을 이용한 홍수조절용댐 내 부유쓰레기 거동 모의에 관한 연구)

  • Jang, Suk-Hwan;Oh, Kyoung-Doo;Oh, Ji-Hwan
    • Journal of Environmental Science International
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    • v.25 no.9
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    • pp.1253-1267
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    • 2016
  • After large-scale flooding damage occurred along the Imjin river in 1996, 1998, and 1999, the Hantan river flood control dam was planned, and it has since been under construction. Unlike existing dams in Korea, the Hantan river flood control dam will remain fully open except during high floods, when the dam will store flood water temporarily to reduce flood peaks and flood water volume downstream. During past flooding seasons, floating debris has caused difficulties in the management of large-scale dams. Most of the existing multipurpose dams in Korea have installed nets to collect floating debris based on many years of experience with and data about inflow and distribution of floating debris in the dams. For the Hantan river flood control dam, however, collection of data about inflow and distribution of floating debris is not possible as the dam is located near the border area between North and South Korea. In order to devise a preliminary plan to collect floating debris in the Hantan river flood control dam, an EFDC hydrodynamic model was used to analyze the behavior of floating debris during high floods. The Lagrangian particle tracking method was utilized to simulate the behavior of floating debris in the dam. Based on the analysis of paths and final destinations of the particles, seven collection points were selected where it seemed to be effective to collect floating debris, as debris is likely to accumulate there in high density.

Development of a Flood Runoff and Inundation Analysis System Associated With 2-D Rainfall Data Generated Using Radar III. 2-D Flood Inundation Simulation (레이더 정량강우와 연계한 홍수유출 및 범람해석 시스템 확립 III. 2차원 홍수범람 모의)

  • Choi, Kyu-Hyun;Han, Kun-Yeun;Kim, Sang-Ho;Lee, Chang-Hee
    • Journal of Korea Water Resources Association
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    • v.39 no.4 s.165
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    • pp.347-362
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    • 2006
  • In this study, a 2-D flood inundation model was developed to evaluate the impact of levee failure in a natural basin for flood analysis. The model was applied to analyze the inundation flow from the levee break of Gamcheon river during the typhoon Rusa on October 31 through September 1, 2002. To verify the simulated results, wide range field surveys have been performed including the collection of NGIS database, land use condition, flooded area, and flow depths. Velocity distributions and inundation depths were presented to demonstrate the robustness of the model. Model results have good agreements with the observed data in terms of flood level and flooded area. The model is able to compute maximum stage and peak discharge efficiently in channel and protected lowland. Methodology considering radar-rainfall estimation using cokriging scheme, flood-runoff and inundation analysis in this study will contribute to the establishment of the national integrated flood disaster prevention system and the river or protect lowland management system.

Evaluation System of Flood Damages using Stream Stage (하천수위에 의한 침수피해 평가 시스템)

  • Kim, Jong-Soon;Lee, Young-Dai;Oh, Kook-Yul
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.1
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    • pp.151-158
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    • 2009
  • Many people have been suffering and loosing their property from inundation due to concentrated rain and massive storm. Although, river banks are strengthened and pumping stations are constructed to protect the life and property of people, the flood damages (disaster)could not be controlled, in fact it is increasing. In USA, CWMS (Corps Water Management System) has very good system of integration of study of rainfall data, computation of stream stage and simulation of flood damages, but there is lack of this type of study and analysis in the domestic context, so we have been facing many difficulties in simulation of flood damages. Therefore, a systematic collecting of data analysis and evaluation of flood damages is necessary. The main objective of this study is to suggest a systematic data collection and evaluation method, which could be useful to prevent the life and property from unusual damages. In this study, the system (Flood Damage Evaluation Model; K-FDEM) is proposed to evaluate the flood damages from rainfall with considering many field parameters.

School Food Service in Korea: Investigation of the Operation and Management Systems (학교급식의 운영 현황 및 실태 조사)

  • 이영은;양일선;차진아;채인숙;강혜승
    • Korean Journal of Community Nutrition
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    • v.7 no.3
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    • pp.361-372
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    • 2002
  • The purpose of this study was to investigate the operation and management systems of the school food services in Korea and to provide useful data for improving the quality of the school food services. This study was conducted in school food service operations nationwide using a written questionnaire. The questionnaires were mailed to the dieticians of three types of school food service systems-conventional, commissary, and joint-management. Of the 660 schools that participated in this study, the responses from 212 conventional system, 212 commissary system and 200 joint-management system services were selected for analysis. Statistical analysis was performed utilizing the SAS/Win 6.12 program so as the provide a descriptive statistics. The main results of this study can be summarized as follows: The average number of meals served per day was 1014, 738 and 695 in the conventional food service, the commissary food service and the joint-management flood service systems, respectively. Over half (58.9%) of food service facilities were utilizing computer programs for their operations. Most of the commissary flood service systems (52.4%) had a satellite school and served a maximum of 2000 meals per day. In most of the joint-management food service systems (87.1%), the number of food service schools managed was two and a maximum of 3330 meals were sewed. Only one dietician was posted irrespective of the school food service system. The mean hours of work by the dietician per day was 8.9, 8.6 and 8.6 in the conventional food service, the commissary flood service and the joint-management food service systems, respectively. The principal work functions of cook personnel were cooking and cleaning.

A Study on Close-to-Nature River Management for the Disaster Prevention (재해예방 중심의 자연형 하천정비 방안에 관한 연구)

  • Seo, Jung Pyo;Cho, Won Chul
    • Journal of Korean Society of Disaster and Security
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    • v.6 no.3
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    • pp.19-27
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    • 2013
  • Along with green growth era in the 21st century and with the increasing economic, social, and cultural stabilization, people expect absolute freedom from the drought and flood and long for ecological exchange in the waterfront as a part of the living base at the same time. In order to match the changes in social demand, the focus on the river management policy urgently requires a comprehensive river management that considers the nature's environmental and ecological aspects as well as a new disaster prevention approach that grows out of existing simple flood prevention. Therefore, this thesis provides feasible solutions by suggesting the following findings to maintain and manage rivers to be harmonized with the natural environment considering disaster prevention aspects. It is necessary to change the river management policy and integrated river basin management, to control the river management lead by the central government and to promote close-to-nature river management approach for environmentally sound and sustainable development.

Determination of management water level for the storage and flood controls in the underflow type of multi-stage movable weir using artificial neural network (인공신경망을 이용한 다단 배치된 하단배출형 가동보의 저류 및 홍수 조절을 위한 관리수위 결정)

  • Lee, Ji Haeng;Han, Il Yeong;Choi, Heung Sik
    • Journal of Korea Water Resources Association
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    • v.50 no.2
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    • pp.111-119
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    • 2017
  • The underflow type movable weirs were arranged in a multi-stage way along a reach at the Chiseong River, where flooding has been observed frequently. With management water level of the movable weirs the control effects of storage and flood were suggested and the control effects were compared with those of existed weir system. The water level for the targeted storage and flood elevation was suggested by building the artificial neural network model. When the underflow type of movable weirs were arranged in a multi-stage way, the peak flood elevation decreased by 68.28% in the downstream compared with the existed weir system, and the total storage of the target section of multi-stage movable weirs increased by 216%. As a result of numerical simulation to build the artificial neural network model, 60%, 20%, and 20% among 216 data were used for the training, validation, and test, respectively. The training result of mean square error was $0.1681m^2$ and the high coefficients of determination were 0.9961, 0.9967, and 0.9943 in the training, validation, and test, respectively. As a result the water level management of each movable weir for the controls of flood elevation in the targeted downstream and targeted storage was suggested by using the artificial neural network.

Development of a Prototype for GIS-based Flood Risk Map Management System (GIS를 이용한 홍수위험지도 관리시스템 프로토타입 개발에 관한 연구)

  • Kim, Kye-Hyun;Yoon, Chun-Joo;Lee, Sang-Il
    • Journal of Korea Water Resources Association
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    • v.35 no.4 s.129
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    • pp.359-366
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    • 2002
  • The damages from the natural disasters, especially from the floods, have been increasing. Therefore, it is imperative to establish a BMP to diminish the damages from the floods and to enhance the welfare of the nation. Developed countries have been generating and utilizing flood risk maps to raise the alertness of the residents, and thereby achieving efficient flood management. The major objectives of this research were to develop a prototype management system for flood risk map to forecast the boundaries oi the inundation and to plot them through the integration of geographic and hydrologic database. For more efficient system development, the user requirement analysis was made. The GIS database design was done based on the results from the research work of river information standardization. A GIS database for the study area was built by using topographic information to support the hydrologic modeling. The developed prototype include several modules; river information edition module, map plotting module, and hydrologic modeling support module. Each module enabled the user to edit graphic and attribute data, to analyze and to represent the modeling results visually. Subjects such as utilization of the system and suggestions for future development were discussed.

Cause Analysis and Improvement Suggestion for Flood Accident in Dorimcheon - Focused on the Tripping and Isolation Accidents (도림천에서 발생한 고립 및 실족사고의 원인분석을 통한 개선방안 도출에 관한 연구)

  • Lee, Kyung-Su;Jeon, Jong-Hyeong;Kim, Tai-Hoon;Kim, Hyunju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.25-36
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    • 2021
  • This study analyzed the causes of flood accidents, such as isolation and lost footing accidents in Dorimcheon, to provide legal and institutional improvements. For cause analysis, Field Investigation, Stakeholder Interview, Report, manual, Law et al. Review, Analysis of water level change characteristics, automatic alarm issuance standard level analysis, and evacuation time according to river control were evaluated. Dorimcheon has the characteristics of a typical urban river, which is disadvantageous in terms of water control. In addition, the risk of flood accidents is high because the section where fatal accidents occur forms sharply curved channels. Tripping and isolation accidents occur in the floodplain watch and evacuation stage, which is the stage before the flood watch and warning is issued. Because floodplain evacuation is issued only when the water level rises to the floodplain, an immediate response according to the rainfall forecast is essential. Furthermore, considering that the rate of water level rise is up to 2.62 cm/min in Sillimgyo 3 and Gwanakdorimgyo, sufficient evacuation time is not secured after the floodplain watch is issued. Considering that fatal accidents occurred 0.46 m below the standard water level for the flood watch, complete control is very important, such as blocking the entry of rivers to prevent accidents. Based on these results, four improvement measures were suggested, and it is expected to contribute to the prevention of Tripping and Isolation Accidents occurring in rivers.

The development of design-width prediction equation by using 12 local governments data collected from small stream of Korea (국내 12개 시·도 자료를 이용한 소하천 계획하폭 산정식 개발)

  • Choi, Changwon;Cheong, Tae Sung
    • Journal of Korea Water Resources Association
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    • v.56 no.3
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    • pp.185-194
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    • 2023
  • There are more than 22,300 small streams distributed nationwide in Korea, and they have various runoff characteristics depending on basin area, topography and land use. For small stream disaster management, establishing detailed design standards suitable for the small streams is important, but most of the formulas currently proposed in the small stream design standard are based on the river design standard aimed at national and local rivers or foreign river design standards. The design-width is an important factor in determining the size of the stream. It is determined by using design-flood discharges or more variables such as design-flood discharges, basin area, slop, etc in the small stream design standard. This study collected various characteristics information such as the design-flood discharges, basin area, river length and river slop, and design-width values from 4,073 small streams distributed in 12 cities and provinces in Korea to suggest the appropriated design-width formula. This study developed two design-width formulas by using the regression analysis which one is using the design-flood discharges and the other is using various variables such as the design-flood discharges, basin area, river length and river slope collected from the small steams. It is expected that both equations developed in here can be used for small stream disaster management, such as improving small stream design standard or establishing a comprehensive small stream maintenance plan.