• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.997-1006
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• 2015

This study analyzed urban infrastructure risk to flooding based on the possibility map of flooding calculated by neural network model focusing on Seoul. This study found that Gangnam-gu, Songpa-gu, Seocho-gu and Seodaemun-gu contained relatively large high-risk areas to flooding. Over $4.17km^2$ of transportation facilities were located in high-risk area to flooding and Gangnam-gu included over $0.85km^2$ of infrastructures exposed to high inundation risk. This study is meaningful in that it first applied the neural network modeling to flooding risk assesment and results of risk assessment can be incorporated into various planning process.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.331-340
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• 2000

This study aims to develop a methodology of real time forecasting of mundation risk based on DAMBRK model and Kalman filter. The model is based on implicit, nonlinear finite difference approximatIons of the one-dimensional dynamic wave equations. The stochastic estimator uses on extended Kalman filter to provide optimal updating estimates. These are accomplished by combining the predictions of the determurustic model with real time observauons modified by the Kalman filter gain ractor. Inundation risks are also estimated by applying Monte Carlo simulation to consider the variability in cross section geometry and Manning's roughness coefficient. The model calibrated by applying to the floods ot South Han River on September, 1990 and August, 1995. The Kalman tilter model indicates that significant improvement compared to deteriministic analysis in flood routing predictions in the river. Overtopping risk of levee is also presented by comparing levee height with simulated flood level. level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2933-2939
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• 2015

Premium rate should be applied the insurance objects are classified reasonably, depending on the degree of exposure to disaster risk. But the existing premium rate is applied same basic rate each cities and districts without the degree of exposure to disaster risk. In this study, we analyzed the exposure to flood risk using channel buffering and suggested way to classify the premium rate by reflecting the analysis results in order to improve its. It is determined that this study would contribute to calculate the storm and flood insurance basic rate reflected risk and make and analysis of flood risk of the local river that conditions of inundation simulation is insufficient.

• Smart Structures and Systems
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• v.23 no.2
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• pp.185-194
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• 2019

The probabilistic tsunami risk assessment of large coastal areas is challenging because the inland propagation of a tsunami wave requires an accurate numerical model that takes into account the interaction between the ground, the infrastructures, and the wave itself. Classic mesh-based methods face many challenges in the propagation of a tsunami wave inland due to their ever-moving boundary conditions. In alternative, mesh-less based methods can be used, but they require too much computational power in the far-field. This study proposes a hybrid approach. A mesh-based method propagates the tsunami wave from the far-field to the near-field, where the influence of the sea floor is negligible, and a mesh-less based method, smooth particle hydrodynamic, propagates the wave onto the coast and inland, and takes into account the wave structure interaction. Nowadays, this can be done because the advent of general purpose GPUs made mesh-less methods computationally affordable. The method is used to simulate the inland propagation of the 2004 Indian Ocean tsunami off the coast of Indonesia.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2200-2204
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• 2009

In this paper the analysis of natural cause of Beijing Storm inundation and the effect of the human activities has been taken. Flood risk can hardly be eliminated solely by projects. Pre-warning system established is an efficient measure to minimize the influence of flood. Several main functions of this system and their examples are described in the paper, such as: monitoring, forecast, scheme, warning, dynamic decision-making and information publication.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.103-104
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• 2012

본 연구에서는 도시 소유역간 상대적 침수위험도 산정을 위하여 엔트로피(Entropy) 기법 및 다기준의사결정 방법의 하나인 프로메티(Preference Ranking Organization METHod for Enrichment Evaluations, PROMETHEE)를 적용하였다. 이에 따라 도시유역 침수위험도 산정과 관련된 항목 6개를 선정하여 평가기준으로 적용하였으며, 실제 도시유역에 적용 및 해당 유역의 과거 집중호우에 따른 침수이력과 비교하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.2
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• pp.231-243
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• 2016

This study presents the applicability of two-dimensional (2D) flood inundation model by applying to real irrigation reservoir failure with limited available data. The study area is Sandae Reservoir placed in Gyeongju and downstream area of it and the reservoir was failured by piping in 2013. The breach hydrograph was estimated from one-dimensional (1D) hydrodynamic model and the discharge was employed for upstream boundary of 2D flood inundation model. Topography of study area was generated by integrating digital contour map and satellite data, and Cartesian grids with 3m resolution to consider geometry of building, road and public stadium were used for 2D flood inundation analysis. The model validation was carried out by comparing predictions with field survey data including reservoir breach outflow, flood extent, flood height and arrival time, and identifying rational ranges with allowed error. In addition, the applicability of 2D model is examined using different simulation conditions involving grid size, building and roughness coefficient. This study is expected to contributed to analysis of irrigation reservoirs were at risk of a failure and setting up Emergency Action Plan (EAP) against irrigation reservoir failure.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.101-110
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• 2010

The increased occurrence of flooding due to typhoons and local rainfall has necessitated damage prevention through the systematic construction of damage history and quantitative analysis of flood prediction data. In this study, we constructed a disaster information map for practical use by combining digital images and continuous cadastral maps of damaged areas using a geographic information system to provide basic data and attribute information. In addition, we predicted the areas at risk of flash floods by calculating the flood capacity of the study area for different rainfall frequencies through flood inundation simulation, which was used to obtain comprehensive disaster information. Further, we calculated the extent of the flooded area and the damage rate for different rainfall frequencies using cadastral information. Flood inundation simulation in the case of heavy rainfall was found to help improve the ability to react to a flood and enhance the efficiency of rescue work by supporting decision-making for disaster management.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.397-397
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• 2015

The frequency of urban floods is recently increased as a consequence of climate change and haphazard development in urban area. To mitigate and prevent the flood damage, we generally utilized a numerical model to investigate the causes and risk of urban flood. Contrary to general flood inundation model simulating only the surface flow, the model needs to consider flow of the sewer network system like SWMM and ILLUDAS. However, this kind of model can not consider the interaction between the surface flow and drainage network. Therefore, we tried to evaluate the impact of bidirectional interaction between sewer and surface flow in urban flooding analysis based on simulations using the quasi-interacted model and the interacted model. As a general quasi-interacted model, SWMM5 and FLUMEN are utilized to analyze the flow of drainage network and simulate the inundation area, respectively. Then, FLO-2D is introduced to consider the interaction between the surface flow and sewer system. The two method applied to the biggest flood event occurred in July 2011 in Sadang area, South Korea. Based on the comparison with observation data, we confirmed that the model considering the interaction the sewer network and surface flow, showed a good agreement than the quasi-interacted model.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.1079-1089
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• 2017

Nuclear power plants under expansion and under construction in China are mostly located in coastal areas, which means they are at risk of suffering strong earthquakes and subsequent tsunamis. This paper presents a safety analysis for a new reinforced concrete containment vessel in such events. A finite element method-based model was built, verified, and first used to understand the seismic performance of the containment vessel under earthquakes with increased intensities. Then, the model was used to assess the safety performance of the containment vessel subject to an earthquake with peak ground acceleration (PGA) of 0.56g and subsequent tsunamis with increased inundation depths, similar to the 2011 Great East earthquake and tsunami in Japan. Results indicated that the containment vessel reached Limit State I (concrete cracking) and Limit State II (concrete crushing) when the PGAs were in a range of 0.8-1.1g and 1.2-1.7g, respectively. The containment vessel reached Limit State I with a tsunami inundation depth of 10 m after suffering an earthquake with a PGA of 0.56g. A site-specific hazard assessment was conducted to consider the likelihood of tsunami sources.