• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.251-251
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• 2021

최근 기후변화로 인한 집중호우의 영향으로 홍수 시 댐으로의 유입량이 설계 당시보다 증가하여 댐의 안전성 확보가 필요하다(감사원, 2003). 이에 건설교통부(2003)는 기후변화와 댐 노후화에 대비하여 치수능력증대사업을 추진하여 댐의 홍수배제능력을 확보하였고, 환경부(2020)에서는 40년 이상 경과된 댐을 대상으로 스마트 안전관리체계 구축을 통한 선제적 보수보강, 성능개선 및 자산관리로 댐의 장수명화를 목적으로 댐의 국가안전대진단을 추진하고 있다. 이에 본 연구에서는 댐 시설(여수로)의 노후도 평가 시 활용 될 수 있는 여수로 표면손상 원인규명에 대하여 3차원 수치모형(FLOW-3D 및 COMSOL Multiphysics)을 통해 검토하고자 한다. 연구대상 댐은 𐩒𐩒댐으로 지형 및 여수로를 구축하였으며, 계획방류량(200년 빈도) 및 최대방류량(PMF) 조건에서 모의를 수행하였다. 수치모의 계산의 정확도 검토를 위하여 Baffle의 설치를 통하여 시간에 따른 유량의 변화를 설계 값과 비교하였고 오차가 1.0% 이내를 만족하는 것을 확인하였다. 여수로 표면손상의 다양한 원인 중 기존연구(USBR, 2019)를 통하여 공동침식(Cavitation Erosion) 및 수력잭킹(Hydraulic Jacking)에 초점을 두었으며 방류조건 별 공동지수(Cavitation Index)산정을 통하여 공동침식 위험 구간을 확인하였다. 이음부의 균열 및 공동으로 인한 표층부 콘크리트의 탈락현상을 가속화시키는 수력잭킹 검토를 위하여 국부모형을 구축하였고 음압력(Negative Pressure), 정체압력(Stagnation Pressure), 양압력(Uplift Pressure)의 분포를 확인하였다. 최종적으로 COMSOL Multiphysics를 통하여 압력분포에 따른 구조해석을 수행하여 폰 미세스(Von Mises) 등가응력 및 변위를 검토하여 콘크리트의 탈락가능성을 확인하였다. 본 연구는 여수로 공동부 및 균열부에서의 손상메커니즘을 확인할 수 있는 기초적인 연구이지만 향후에는 다양한 지형조건 및 흐름조건에서의 압력분포 분석 및 유체-구조물 상호작용(Fluid-Structure Interaction, FSI)모의를 수행한다면 구조물 노후도 및 잔존수명 평가에 필요한 손상한계함수 도출이 가능할 것으로 기대된다.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.501-510
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• 2014

Volcanic eruptions alone may lead to serious natural disasters, but the associated release of water from a caldera lake may be equally damaging. There is both historical and geological evidence of the past eruptions of Mt. Baekdusan, and the volcano, which has not erupted for over 100 years, has recently shown signs of reawakening. Action is required if we are to limit the social, political, cultural, and economic damage of any future eruption. This study aims to identify the area that would be inundated following a volcanic flood from the Cheon-Ji caldera lake that lies within Mt. Baekdusan. A scenario-based numerical analysis was performed to generate a flood hydrograph, and the parameters required were selected following a consideration of historical records from other volcanoes. The amount of water at the outer rim as a function of time was used as an upper boundary condition for the downstream routing process for a period of 10 days. Data from the USGS were used to generate a DEM with a resolution of 100 m, and remotely sensed satellite data from the moderate-resolution imaging spectroradiometer (MODIS) were used to show land cover and use. The simulation was generated using the software FLO-2D and was superposed on the remotely sensed map. The results show that the inundation area would cover about 80% of the urban area near Erdaobaihezhen assuming a 10 m/hr collapse rate, and 98% of the area would be flooded assuming a 100 m/hr collapse rate.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.1-14
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• 2022

Recently, the risk of water disasters are increasing due to climate change and the aging of river levees. Existing conventional river embankment inspections have many limitations due to the consumption of a lot of manpower and budget. Thus, it is necessary to establish a new monitoring and forecast/warning method for effective flood response. This study proposes the river levee health monitoring system by analyzing the relationship between river levee deformation and hydrological factors using Sentinel-1. The variance index calculated in this study was classified into 4 grades. And the levees collapse section was judged to be a high vulnerable point in which the variance rapidly increased based on the result of the rapid increase in soil moisture. In the future, it is expected that it will be possible to advance levee maintenance technology and improve national disaster management through the advancement of the existing levee management system and automated monitoring through the forensic method that combines remote technology.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.4
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• pp.537-545
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• 2018

Determination of the time parameters such as the travel time in the design flood is very important. The travel time is mainly used for flood and river management, and the travel time of non flood season is used for maintenance flow and management of the river. Estimation of travel time for natural rivers is mainly based on the geomorphological factors of the basin. In addition to the topographical factors, the travel time is calculated by considering the factors of the runoff curve, velocity and rainfall intensity. However, there is no study on the estimation of travel time considering both the rainfall condition and the soil moisture accounting by the frequency period. Therefore, the travel time calculation is divided into the case of setting the Hwanggang Dam and the Imjin bridge water level station of Imjin river as the natural river considering rainfall condition by the frequency period and the soil moisture accounting, and the case of traveling the Imjin bridge water level station according to the condition of outflow of the Hwanggang Dam. For the sections set as natural rivers, the results were verified by comparing with the newly developed travel time calculation method. Based on the results, the travel times of the Hwanggang Dam outflow conditions were calculated. The time to travel in this study can be secured flood control of the Imjin river basin and time to prepare for danger when outflowing the the Hwanggang Dam.

• Journal of the Korean Geotechnical Society
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• v.34 no.6
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• pp.25-36
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• 2018

Soil liquefaction is one of the types of major seismic damage. Soil liquefaction is a phenomenon that can cause enormous human and economic damages, and it must be examined before designing geotechnical structures. In this study, we proposed a practical method of developing a multi-hazard fragility surface for liquefaction of levee considering earthquake magnitude and water level. Limit state for liquefaction of levee was defined by liquefaction potential index (LPI), which is frequently used to assess the liquefaction susceptibility of soils. In order to consider the uncertainty of soil properties, Monte Carlo Simulation based probabilistic analysis was performed. Based on the analysis results, a 3D fragility surface representing the probability of failure by soil liquefaction as a function of the ground motion and water level has been established. The prepared multi-hazard fragility surface can be used to evaluate the safety of levees against liquefaction and to assess the risk in earthquake and flood prone areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.468-468
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• 2017

최근 기후변화로 인해 수자원 위험요소인 가뭄 및 홍수피해가 증가하고 있으며, 인구증가에 따른 수량감소로 수자원관리가 더욱 어려워지고 있는 실정이다. 효율적인 수자원관리 및 기후변화 대응을 위해 세계 물시장은 점점 증가하고 있으며, 이에 따라 국내기업 또한 해외사업 진출을 추진하고 있으나, 사업에 필수적인 기상, 수문 등 기초자료의 부재로 어려움을 겪고 있다. 본 연구에서는 국내기업의 해외사업 진출 시 필요한 기상, 지형, 수문, 인문 사회 등 기초자료를 제공하는 글로벌 수자원정보제공시스템(Global Water Bank, GWB)을 설계 및 개발하고자 한다. 국내 외 예비타당성보고서 및 국내에서 수집 가능한 국외 정보현황을 분석하여 자료 제공인자를 도출하였으며, 이를 토대로 시스템 내 제공항목을 기상, 지형, 수문해석, 인문 사회, 기후변화 자료로 구분하였다. 해외시장 진출범위를 고려하여 자료의 공간적인 범위를 전지구로 설정하였으며, 전지구 자료의 가용성을 검토하여 제공자료를 구축하였다. 기상자료는 NCDC (National Climate Data Center)의 관측 지점자료와 APHRODITE (Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation) 격자자료를 수집하였으며, 오 결측 자료는 품질검토를 수행하여 보정하였다. 지형자료의 경우 USGS (U.S. Geological Survey)의 DEM, FAO (Food and Agriculture Organization of the United Nations)의 토양도, UMD (University of Maryland)의 토지피복도를 구축하였다. 수문자료는 GRDC(Global Runoff Data Centre)의 관측 지점자료를 수집하였으며, 미계측 지역의 수문자료 구축을 위해 VIC(Variable Infiltration Capacity) 수문모형을 활용하여 $0.5^{\circ}$ 공간해상도의 격자 유출량 자료를 생산하였다. 인문 사회자료로 World Bank의 국가별 통계자료를 수집하였으며, 구축된 각 자료는 GWB 시스템을 통해 제공된다. 시스템의 시범운영을 위해 아시아 지역을 대상으로 GWB- 버전을 개발하였으며, 시범지역 내 관측자료와 비교분석하여 자료의 활용성을 검증하였다. 추후 GWB 시스템은 해외진출 사업 우선지역 선정 근거로 활용될 수 있는 가상수 및 물산업지수 등의 추가정보를 제공하고 타 지역으로 확대적용 예정이다.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.133-141
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• 2011

Urban development of basin causes increasing runoff volume and peak flowrate and shortening in time of concentration, which may cause frequent flooding downstream. An infiltration facilities are operated as a method of reducing flood discharge of urban rivers and peak flowrate. There are various types of infiltration facilities like infiltration trench and porous pavement. In this study, runoff reduction effect due to installation of infiltration facilities are performed and focused on $0.18km^2$ residential area of Ok-kye dong and $0.67km^2$ industrial area of Gong-dan dong in Gumi City. The analysis is fulfilled with comparison of total runoff volume and runoff reduction volume by using the WinSLAMM and the relation equation between area ratio of infiltration facilities and ratio of runoff reduction are derived and peak flow reduction effect for installation of infiltration facilities is analyzed.