• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.21-26
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• 2004

Annually repeated flood damage is bringing about the rapid increasement of the loss of human lives and properly, and the enormous social cost for the restoration work is required. The annual amount of flood damage caused by the abnormal climate is reached about 1% of GDP, so more effective management of the flood control operation is needed to prevent the repetitive flood occurred same region. Also, the systematic planning and management or river improvement works are keenly required for the more effective execution of government working budget that expense to recover or to prevent the flood damage. The several organizations of government - Ministry of Construction & Transportation, Ministry of Government Administration and Home Affair, Ministry of Agriculture and Forestry, Ministry of Environment, Ministry of Science & Technology, Korea Meteorological Adminstration and so on - are promoting the flood prevention operations, but those promotion system makes it difficult to maintain the consistency of works. In this study, we try to develop the Web-GIS system prototype that will be able to effectively manage the nationwide river improvement works and to establish a framework that will be able to maintain the consistency of river improvement works. To achieve the study goals, we analysed current system of flood prevention operations, gathered related documents, had interviews with many government employees, and developed the Web-GIS system prototype.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.4
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• pp.344-353
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• 2016

The cause of abnormal tidal residuals was examined by analyzing sea levels, sea surface atmospheric pressures, winds at ten tide stations, and current, measured at the coast of the Yellow Sea from the night of November $24^{th}$ to the morning of the $25^{th}$ in 2013, along with weather chart. Additionally, the cross-correlations among the measured data were also examined. The 'abnormal tidal residuals' mentioned in this study refer to differences between maximum and minium tidal residuals. The largest abnormal tidal residual was identified to be a difference of 176 cm occurring over 4 hours and 1 minute at YeongJongDo (YJD) with a maximum tidal residual of 111 cm and minimum of -65 cm. The smallest abnormal tidal residual was 68 cm at MoSeulPo (MSP) during 8 hours 52 minutes. The cause of these abnormal tidal residuals was not a meteo-tsunami generated by an atmospheric pressure jump but wind generated by the pressure patterns. The flow speed due to these abnormal tidal residuals as measured at ten tide stations was not negligible, representing 16 ~ 41 % of the annual average ebb current speed. From the cross correlation among the tidal residuals, winds, and tidal residual currents, we learned the northern flow, due to southerly winds, raised the sea level at Incheon when a low pressure center located on the left side of the Korean Peninsula. After passing the Korean Peninsula, a southern flow due to northerly winds decreased the sea level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.39-44
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• 2016

Recently, there has been increasing concern regarding the collapse of hydraulic structures due to abnormal climate conditions. Therefore, numerous studies of the collapse of hydraulic structures have been carried out. In particular, the velocity of the propagation of a flood wave-front is important for predicting the inundation safety and establishing an EAP (Emergency Action Plan). Although many hydraulic tests have been conducted for precise predictions of a flood wave-front, the scale effect from downsizing has not considered. In this study, the relationships between surface tension and the concentration of surfactant, between surface tension and the velocity of flood wave propagation, and between surface tension and the Weber Number were derived through hydraulic tests using a surfactant and image analysis equipment. Based on these relations, the modification factor for the scale effect of the front of flood wave propagation was suggested. The results highlight the necessity of a modification factor when the Weber Number is lower than 12.2, but the scale effect can be ignored when the Weber Number over 12.2.

• Journal of Wetlands Research
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• v.22 no.3
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• pp.187-193
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• 2020

The increase in the area of impervious water due to the recent abnormal weather conditions and rapid urbanization led to a decrease in the amount of low current, resulting in an increase in the amount of surface runoff. Increased surface runoff is causing erosion, destruction of underwater ecosystems, human and property damage in urban areas due to flooding of urban river. The damage has been increasing in Korea recently due to localized heavy rains, typhoons and floods. As a countermeasure, the Busan Metropolitan Government will proceed with the creation of the Eco-Delta City waterfront zone in Busan with the aim of creating a future-oriented waterfront city from 2012 to 2023. Therefore, the current urban river conditions and precipitation data were collected by utilizing SWMM developed by the Environment Protection Agency, and the target basin was selected to simulate flood damage. Measures to reduce flood damage in various cases were proposed using simulated data. It is a method to establish a disaster prevention plan for each case by establishing scenario for measures to reduce flood damage. Considering structural and non-structural measures by performing an analysis of the drainage door with a 30-year frequency of 80 minutes duration, the expansion effect of the drainage pump station is considered to be greater than that of the expansion of the drainage door, and 8 scenarios and corresponding alternatives were planned in combination with the pre-excluding method, which is a non-structural disaster prevention measure. As a result of the evaluation of each alternative, it was determined that 100㎥/s of the pump station expansion and the pre-excluding EL.(-)1.5m were the best alternatives.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.83-90
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• 2023

Due to climate change, the occurrence of abnormal rainfall is increasing, and the intensity and scale of damage caused by heavy rain are increasing every year. In addition, as the frequency of heavy rains becomes more frequent, heavy rains often occur continuously, resulting in large flooding damage that has never been seen before in urban area. When near rivers and coastal areas are impermeable areas, the maximum flow increases rapidly as the rainfall intensity increases, so a comprehensive flood risk evaluation is needed considering the characteristics of the basin. In this study, the flood inundation risk evaluation was analyzed by giving scores on evaluation factors as a measure to prevent inundation in subway stations. Through the flood inundation risk evaluation process considering the comprehensive evaluation index, the flood risk evaluation was conducted on five urban railway stations with a large amount of traffic and floating population that had been inundated in the past. It is judged that by comprehensively analyzing this and establishing a inundation risk grade (grade 1 to 4) to establish a flood measure suitable for the risk grade.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.169-177
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• 2010

Recently due to the typhoon and extreme rainfall induced by abnormal weather and climate change, the probability of severe damage to human life and property is rapidly increasing. Thus it is necessary to create adequate and reliable flood risk map in preparation for those natural disasters. The study area is Seo-gu in Daegu which is located near Geumho river, one of the tributaries of Nakdong river. Inundation depth and velocity at each time were calculated by applying FLUMEN model to the target area of interest, Seo-gu in Daegu. And the research of creating flood risk map was conducted according to the Downstream Hazard Classification Guidelines of USBR. The 2-dimensional inundation analysis for channels and protected lowland with FLUMEN model was carried out with the basic assumption that there's no levee failure against 100 year precipatation and inflow comes only through the overflowing to the protected lowland. The occurrence of overflowing was identified at the levee of Bisan-dong located in Geumho watershed. The level of risk was displayed for house/building residents, drivers and pedestrians using information about depth and velocity of each node computed from the inundation analysis. Once inundation depth map and flood risk map for each region is created with this research method, emergency action guidelines for residents can be systemized and it would be very useful in establishing specified emergency evacuation plans in case of levee failure and overflowing resulting from a flood.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.6
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• pp.655-662
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• 2010

Recently, disasters are increasing rapidly due to global warming and abnormal weather conditions, and the scale of damage is also getting wider. In this study, the application of UAV is analyzed based on previous study about disaster and analysis of regulations for disaster. Also, this study is proposed application model to prepare, reponse and restoration from natural disaster to make use of the UAV. This UAV is quick and economic for existing technology, and available to various disaster monitoring. UAV application for disaster monitoring is able to support effective management of disaster by real time aerial monitoring for reponse from natural disaster and damage assessment.

• Journal of Korean Society of Disaster and Security
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• v.13 no.2
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• pp.39-51
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• 2020

Recently, flood damage has been increasing in Korea due to frequent local torrential rains caused by abnormal weather conditions. According to the calculation of the recurrence period of torrential rain that occurred in North Chungcheong Province on July 16, 2017, it was estimated that the rainfall frequency in the upper are of Goessan Dam was around 1,524 years, and the highest level of Goesan Dam rose to EL.137.60 meters, leaving only 5 cm of margin until the height of the dam floor (EL.137.65 meters). The Goesan Dam, which operated for 62 years since 1957, needs to be prepared to cope with the increase of floodgate volume in the basin, the development of a single purpose dam for power generation only, and there are no measurement facilities for flood control, so efficient operation methods are needed to secure the safety of residents in upper and lower regions. In this study, a method of dam operation was proposed by constructing a rain matrix for quick decision making in flood prediction, calculating the highest level of dam for each condition in advance, and preparing a survey table, and quickly finding the level corresponding to the conditions in case of a situation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2460-2468
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• 2014

A local rain that is concentrated in specific area in a short time frequently occurs due to recent abnormal weather. To prevent potential flood disasters, therefore, it is necessary to be established to the flood control system. Checking the river design standard, however, hydrologic design frequency of water gate is only marked as over 20 years, so this fact shows that the standard is unclear. The inland inundation modeling considering the stage in a river and quantitative assessment are required to reduce flood damage. The simulation for internal inundation is very complex and is time-consuming due to considering hydraulic hydrology characteristics at the same time. Using the already established river master plan, consequently, this study proposed the simple and convenient method for assessment of the internal inundation simulation. Using the proposed method in the upper and middle regions of a river, influences for design frequency or water gate location were assessed by applying the nine probability precipitation with design frequency and by targeting the water gates which are installed in five inlands.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.793-800
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• 2018

It is necessary to determine an optimal design frequency for establishing stable flood control against frequent flood disasters. Depending on the importance of river and regional characteristics, design return periods are suggested from at least 50 years up to 200 years for river design. However, due to the wide range of applications, it is not desirable to reflect the geographical and flood control characteristics of river. In this study, Bayes theory was applied to seven evaluation factors to determine the optimal design return period of rivers in Chungcheongnam-do; urbanization flooded area, watershed area, basin coefficient, slope, water system and stream order, range of backwater effect, abnormal rainfall occurrence frequency. The potential flood damage (PFD) capacity was estimated considering climate change and the appropriate design return period was determined by analyzing the capacity of each district. We compared the design return periods of 382 rivers in Chungcheongnam-do with the existing design return periods. The number of rivers that were upgraded from the existing return period were 65, which have relatively large flooding areas and have large PFDs. Whereas, the number of rivers that were downgraded were 169.