• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.179-182
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• 2008

This study simulated the flood inundations of the Nakdong River catchment running through Yangsan, a small city located in the south eastern area of Korea by using the depth averaged two-dimensional hydrodynamic numerical model. The numerical model employs the staggered grid system including moving boundary and a finite different method to solve the Saint-Venant equations. A second order upwind scheme is used to discretize the nonlinear convection terms of the momentum equations, whereas linear terms are discretized by a first order leap-frog scheme(Cho and Yoon, 1998). The numerical model was applied to a real topography to simulate the flood inundation of the Yangsan basin. The numerical results for urban district are visualized in three dimension. These results can be essentially utilized to construct the three dimensional inundation map after building the GIS-based database in local public organizations in order to protect the life and property safely.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.74.1-74.1
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• 2009

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.2
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• pp.159-164
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• 2008

This study simulated the flood inundations of the Nakdong River catchment running through Yangsan, a small city located in the south eastern area of Korea by using the depth averaged two-dimensional hydrodynamic numerical model. The numerical model employs the staggered grid system including moving boundary and a finite different method to solve the Saint-Venant equations. A second order upwind scheme is used to discretize the nonlinear convection terms of the momentum equations, whereas linear terms are discretized by a second order Leap-frog scheme(Cho and Yoon, 1998). The numerical model was applied to a real topography to simulate the flood inundation of the Yangsan basin in Yangsan. The numerical result for urban district was visualization for three dimension. These results can be essentially utilized to construct the three dimensional inundation map after building the GIS-based database in local public organizations in order to protect the life and property safely.

• Korean Journal of Hydrosciences
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• v.10
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• pp.59-72
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• 1999

FIAS(Flood Inundation Analysis System) using Arc/Info is developed and applied to the Namhan River basin. The DWOPER model is revised and expanded to handle simultaneous multiple overtopping and/or breaking, and to estimate the inundated depth and extents. The model is applied to an actual levee overtopping case, which occurred on August 23∼27, 1995 in the Namhan River. Stage hydrographs inside and outside of the levee are compared, then inundated discharges from overbank spilling are computed. The Graphic User interface is developed with AML. Two- and three-dimensional inundation map by Arc/Info are presented. The computed inundation extends agree with observations in terms of inundated depth and flooded area. The FIAS is useful for the analysis of flood hazards and preparation of inundation map for river basins.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.91-99
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• 2011

With increasing astronomically damage costs caused by frequent and large-sized flood, a hazard map containing comprehensive analysis results such as inundation trace investigation, flood possibility analysis, and evacuation plan establishment for flooded regions is a fundamental measure of non-structural flood prevention. Though an inundation trace map containing flood investigation results occurred by typhoon, rainfall and tsunami is a basic hazard map having close relationship with a flood possibility map as well as a hazard information map, it is often impossible to be produced because of financial deficiency, time delay of investigation, and the lack of maintenance for flood traces. Therefore, this study proposes the accuracy enhancement procedure of inundation trace map with flood damage information and three-dimensional Digital Elevation Model (DEM) for the past frequent flooded regions according to a guideline for inundation trace map of National Emergency Management Agency (NEMA).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.691-702
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• 2019

Flood inundation map has various important roles in terms of municipal planning, timely dam operation, economic levee design, and building flood forecasting systems. Considering that the riparian areas adjacent to national rivers with high potential flood vulnerability conventionally imposed special cares to justify applications of recently available two- or three-dimensional flood inundation numerical models on top of digital elevation models of dense spatial resolution such as LiDAR irrespective of their high costs. On the contrary, local streams usually could not have benefits from recent technological advances, instead they inevitably have relied upon time-consuming manual drawings or have accepted DEMs with poor resolutions or inaccurate 1D numerical models for producing inundation maps due mainly to limited budgets and suitable techniques. In order to efficiently and cost-effectively provide a series of flood inundation maps dedicatedly for the local streams, this study proposed an OpenGIS-based flood mapping tool named Open Flood Mapper (OFM). The spatial accuracy of flood inundation map derived from the OFM was validated throughout comparison with an inundation trace map acquired after typhoon Nari in Hancheon basin located in Jeju Island. Also, a series of inundation maps from the OFM were comprehensively investigated to track the burst of flood in the extreme flood events.

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.69-77
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• 2014

The objective of this study is to compare flood inundation models for small stream basin. HEC-RAS model was used for the analysis of one dimensional hydraulics and HEC-GeoRAS, Ras Mapper and RiverCAD models were applied for the flood inundation analysis in Gum Chung stream. Flood inundations are to simulate by flood inundation models using observed data and rainfall on each frequency and to compare with inundation area based on the flood plain maps. The results of this study are as follows; Area of flood inundations by HEC-GeoRAS model is similar to that of flood plain map and appears in order of RAS Mapper and RiverCAD model. Flood inundation area by RiverCAD model is to estimate lager than that of RAS Mapper and HEC-GeoRAS model in flood area on each frequency and the results show that they have a little difference in models of flood inundation analysis at small stream. Comparing the area of flood inundations by flood depth, the results of three models are relatively similar in flood depth as 2.0 m below, and RiverCAD model shows a significant difference in flood depth as 2.0 m or more.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.537-544
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• 2017

An experimental study was carried out to investigate the characteristics of the propagation distance of a flood wave considering the levee failure speed in a flat inundation area. The Ritter solution for one dimensional flow was considered to formulate the experimental results and a representative form with coefficients of k and m, which consider the three dimensional flow characteristics, was applied. The experiments showed that the propagation velocity of the wave front in the inundation area was influenced by the levee breach speed as well as the initial water level, which is a significant variable representing the flood wave behavior. In addition, coefficients k and m are not constants, but variables that vary with levee breach speed. An empirical formula was also suggested using the experimental results in the form of the relationships between k and m. In this study, a large-scale experiment for flood inundation was carried out to examine the behavior of flooding in the inundated area and the relationships between the levee breach speed and wave-front propagation velocity were suggested based on the experimental results. These research results are expected to be used as the baseline data to draw a flow inundation map, establish an emergency action plan, and verify the two-dimensional numerical model.

• 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.

• Journal of Korean Society of Disaster and Security
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• v.13 no.2
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• pp.53-63
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• 2020

In this study, the two-dimensional flow analysis model Hydro_AS-2D model was used to simulate the situation of flooding in Seongsangu and Uichang-gu in Changwon in the event of rising sea levels and extreme flooding, and the results were expressed on three-dimensional topography and the optimal evacuation path was derived using BIM technology. Climate change significantly affects two factors in terms of flood damage: rising sea levels and increasing extreme rainfall ideas. The rise in sea level itself can not only have the effect of flooding coastal areas and causing flooding, but it also raises the base flood level of the stream, causing the rise of the flood level throughout the stream. In this study, the rise of sea level by climate change, the rise of sea level by storm tidal wave by typhoon, and the extreme rainfall by typhoon were set as simulated conditions. The three-dimensional spatial information of the entire basin was constructed using the information of topographical space in Changwon and the information of the river crossing in the basic plan for river refurbishment. Using BIM technology, the target area was constructed as a three-dimensional urban information model that had information such as the building's height and location of the shelter on top of the three-dimensional topographical information, and the results of the numerical model were expressed on this model and used for analysis for evacuation planning. In the event of flooding, the escape route is determined by an algorithm that sets the path to the shelter according to changes in the inundation range over time, and the set path is expressed on intuitive three-dimensional spatial information and provided to the user.