• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.47-53
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• 2012

A coastal flood area was predicted using the empirical superposition of the typhoon surge level and typhoon wave height along the Busan coastal area. The historical typhoon damages were reviewed, and the coastal topography was measured using VRS-GPS. A FEMA formula was applied to estimate the coastal flood area in a typhoon case when the measured and predicted data of typhoon waves are not available. The results in the area of Haeundae beach and Gwangalli beach were verified using the flood area data from the case of Typhoon Maemi (2003). If a Hurricane Katrina class typhoon were to pass through the Maemi trajectory, the areathat would be flooded along theBusan coastal area was predicted and compared with the results of the Maemi case. Because of the lack of ocean environment data such as data for the sea level, waves, bathymetry, wind, pressure, etc., it is hard to improve the prediction accuracy for the coastal flood area in the typhoon case, which could be reflected in the policy to mitigate a typhoon's impact. This paper discusses the kinds of ocean environment information that is needed to predict a typhoon's impact with better accuracy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2293-2302
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• 2013

Flood inundation map has been used as a fundamental information in flood risk management. However, there are various sources of uncertainty in flood inundation mapping, which can be another risk in preventing damage from flood. Therefore, it is necessary to remove or reduce uncertainty sources to improve the accuracy of flood inundation maps. However, the entire removal of uncertainty source may be impossible and inefficient due to limitations of knowledge and finance. Sensitivity analysis of uncertainty sources allows an efficient flood risk management by considering various conditions in flood inundation mapping because an uncertainty source under different conditions may propagate in different ways. The objectives of this study are (1) to perform sensitivity analysis of uncertainty sources by different conditions on flood inundation map using the FOA method and (2) to find a major contributor to a propagated uncertainty in the flood inundation map in Flatrock at Columbus, U.S.A. Result of this study illustrates that an uncertainty in a variable is differently propagated to flood inundation map by combination with other uncertainty sources. Moreover, elevation error was found to be the most sensitive to uncertainty in the flood inundation map of the study reach.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.3
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• pp.119-136
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• 2012

The goal of this study is to apply the IPCC(Intergovernmental Panel on Climate Change) concept of vulnerability to climate change and verify the use of a combination of vulnerability index and fuzzy logic to flood vulnerability analysis and mapping in Seoul using GIS. In order to achieve this goal, this study identified indicators influencing floods based on literature review. We include indicators of exposure to climate(daily max rainfall, days of 80mm over), sensitivity(slope, geological, average DEM, impermeability layer, topography and drainage), and adaptive capacity(retarding basin and green-infra). Also, this research used fuzzy model for aggregating indicators, and utilized frequency ratio to decide fuzzy membership values. Results show that the number of days of precipitation above 80mm, the distance from river and impervious surface have comparatively strong influence on flood damage. Furthermore, when precipitation is over 269mm, areas with scare flood mitigation capacities, industrial land use, elevation of 16~20m, within 50m distance from rivers are quite vulnerable to floods. Yeongdeungpo-gu, Yongsan-gu, Mapo-gu include comparatively large vulnerable areas. This study improved previous flood vulnerability assessment methodology by adopting fuzzy model. Also, vulnerability map provides meaningful information for decision makers regarding priority areas for implementing flood mitigation policies.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.172-178
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• 2006

There has been tremendous increase of disaster related damages since 1990's. Especially flood occurred in summer season highly populated area has led to demolish a lot of facilities and buildings within a short time period. This is to figure out the way to predict the vulnerable flood inundation area by past records of inundation and and geographic information available. The comparative study on 1998 and 1999 flood inundation area in Munsan and Gokneung river shows that 5 degree of slope and 10 m elevation level are dividing index to draw the vulnerable area. This study is to suggest the relatively easy method to predict flood vulnerable area and to apply the results to prepare for protecting the facilities and the people with other thematic geographic database.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.271-278
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• 2011

Storm and flood such as torrential rains and major typhoons has often caused damages on a large scale in Korea and damages from storm and flood have been increasing by climate change and warming. Therefore, it is an essential work to maneuver preemptively against risks and damages from storm and flood by predicting the possibility and scale of the disaster. Generally the research on numerical model based on statistical methods, the KDF model of TCDIS developed by NIDP, for analyzing and predicting disaster risks and damages has been mainstreamed. In this paper, we introduced the model for prediction of damage cost from storm and flood by the neural network algorithm which outstandingly implements the pattern recognition. Also, we compared the performance of the neural network model with that of KDF model of TCDIS. We come to the conclusion that the robustness and accuracy of prediction of damage cost on TCDIS will increase by adapting the neural network model rather than the KDF model.

• Proceedings of the KSRS Conference
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• v.1
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• pp.426-429
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• 2006

Flood caused by Typhoon and severe rain during summer is the most destructive natural disasters in Korea. Almost every year flood has resulted in a big lost of national infrastructure and loss of civilian lives. It usually takes time and great efforts to estimate the flood-related damages. Government also has pursued proper standard and tool for using state-of-art technologies. High resolution satellite imagery is one of the most promising sources of ground truth information since it provides detailed and current ground information such as building, road, and bare ground. Once high resolution imagery is utilized, it can greatly reduce the amount of field work and cost for flood related damage assessment. The classification of high resolution image is pre-required step to be utilized for the damage assessment. The classified image combined with additional data such as DEM and DSM can help to estimate the flooded areas per each classified land use. This paper applied object-oriented classification scheme to interpret an image not based in a single pixel but in meaningful image objects and their mutual relations. When comparing it with other classification algorithms, object-oriented classification was very effective and accurate. In this paper, IKONOS image is used, but similar level of high resolution Korean KOMPSAT series can be investigated once they are available.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.183-192
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• 2006

In recent years, the damage caused by flood has been gradually increased. The cause of the flood is unusual weather condition as well as topographical and geographical condition of our country. Flood area analyzing vulnerable flood areas on large regions without previous flood records were developed using GIS and hydraulic model, flood depth by return periods and topographical data such as DEM. The study area is the Munsan river basin. The results using GIS comparing the results using hydraulic model. The results in this study can be used to delineate the potential flooding areas in large regions and the damage from disasters can be reduced by making provisions with the obtained results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.203-213
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• 2018

This study aims to propose the methods for urban flood risk maps which are useful in strengthening urban planning toward disaster prevention by climate change. Selecting the Gwangju city, Gyeonggi-do as study area, it analyzes urban flood at a RCP 8.5 scenario, and develops gridded information regarding risk components such as hazard, exposure, and vulnerability. It turns out that flooding would occur at a bend interval of the Mokhyun stream and also at the joint of the Gyungan and the Mokhyun streams, showing the similarity with the inundation trace map. In particular, the Songjeong dong is analyzed to be seriously exposed and to be highly vulnerable to flood inundation. With all results together, this study concludes that the proposed methods could be used as a basis for strengthening urban planning toward flood disaster prevention system.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.68-80
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• 2013

The purpose of this study is to evaluate the applicability of UK design flood estimation model, FEH-ReFH through rainfall-runoff simulation of Korean watershed. For the Nam stream watershed($165.12km^2$), the model was calibrated using 6 storm events. The watershed and hydrological characteristics for the model requirements was prepared by developing input data pre-processors based on open GIS. The parameters of rainfall loss rate and unit hydrograph were calibrated from the observed data. The results can be used for improving and standardizing the Korean design flood estimation method.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.3 s.37
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• pp.87-95
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• 2006

Recently, local heavy rain for a short term is caused by unusual changing in the weather. This phenomenon has, several times, caused an extensive flash flood, casualties, and material damage. This study is aimed at calculating the characteristics of flash floods in streams. For this purpose, the analysis of topographical characteristics of water basin through applying GIS techniques will be conducted. The flash flood prediction model we used is made with GCIUH (geomorphoclimatic instantaneous unit hydrograph). The database is established by the use of GIS and by the extraction of streams and watersheds from DEM. The streams studied are included small, middle and large scale watersheds. For the first, for the establishment or criteria on the flash flood warning, peak discharge and trigger runoff must be decided. This study analyzed the degree or aptitude of topographical factors to the trigger runoff calculated by GCUH model.