• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.688-692
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• 2007

수리시설개보수사업을 통해 농업용저수지를 보강하는 방법은 여수로의 통수능력을 증대시키기 위해 물넘이 길이를 확장하는 방법과 예비방류가 가능하도록 부분게이트를 설치하여 홍수조절효과를 기대하는 일정량 방류방식을 혼합한 형태로 설계를 하고 있다. 이는 현실적으로 투자가 가능한 예산범위 안에서 최소한의 피해를 줄이기 위해 적절히 적용가능한 방법이다. 하지만 아직까지 게이트의 설치 위치나 형식에 관한 고찰이 없었으며 홍수배제능력검토 방법 또한 일관성 있게 이루어지고 있지 않다. 그리고 유지관리측면에서도 현재 많은 문제점이 나타나고 있다. 비상게이트 설치에 따라 홍수기시 하류지역의 침수피해가 발생하며 유지관리비용도 과거에 비해 상당히 늘어나고 있다. 하지만 최근 국내 기상여건하에서 저수지제체 안전도를 높이기 위해서는 농업용저수지에도 여수로 게이트가 반드시 필요한 실정이다. 농업용저수지의 설계홍수량 증가에 따라 홍수량 배제시설의 규모도 커져야 하나 지형적인 여건상 물넘이의 확장이 불가능한 지역도 많으며 물넘이 시설의 확장으로 인해 저수지 하류지역의 피해에 따른 민원도 제기됨에 따라 농업용저수지 여수로 게이트의 합리적이고 표준화된 모델이 제시되어야 할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.88-88
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• 2016

최근 우리나라에서 발생한 홍수 중 많은 관심을 불러일으킨 2010년 광화문 일대와 2011년 강남역 일대 홍수의 주요 원인은 하천관리를 통하여 대응해온 지금까지의 홍수와는 달리 도시의 우수배제 기능이 높은 강도의 강우에 대응하지 못한 것으로 분석되고 있다. 도시내부에서 발생한 이 같은 홍수는 도시의 기능에 심각한 영향을 줄 수 있으며, 거주민의 안전과도 밀접하게 연관된다. 본 연구에서는 도시의 기능과 거주민의 안전을 우선적으로 고려한 홍수 취약성평가 인자를 선정하고자 한다. 기존의 여러 홍수취약성 연구들에서는 취약성을 평가함에 있어 피해금액을 기준으로 적용하는 경우가 많이 있다. 장기적인 홍수대응, 완화 정책의 구상에 있어 예상되는 피해금액은 중요한 지표라고 볼 수 있다. 그러나 이 방법으로는 도시에서 발생 가능한 피해를 모두 반영하는데 한계가 있다. 도로, 지하철, 철도 등의 교통수단이 침수되는 경우, 피해회복을 위한 비용뿐만 아니라, 도시기능에 심각한 영향을 주어 도시의 생산성, 안정성에 막대한 피해를 남길 수 있다. 따라서 피해금액의 규모에 대한 접근만으로는 도시에서 발생한 홍수에 의해 피해를 받는 취약요인을 적극적으로 반영할 수 없다. 본 연구에서는 도시홍수 피해양상과 이에 대한 대응 방법 등 홍수의 물리적 위험성 뿐 아니라 홍수와 연관된 사회적인 요인들을 반영한 취약성 평가인자를 구성하기위하여 인자간의 인과관계 등을 고려하여 인자의 범위를 규정하고 델파이 설문조사와 문헌 연구를 통하여 전문가 의견을 수집, 분석하였다. 홍수취약성에 영향을 주는 요인들을 크게 3가지 그룹으로 정리하여 도시구조물, 거주민, 위험요인으로 구분하고 각 항목별로 영향인자을 선정하였다. 결정된 인자는 2011년 홍수피해가 발생한 도림천 유역에 적용하여 홍수취약성 평가를 수행하고자 한다.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.529-539
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• 2010

In order to evaluate the effect of soil salinity and culturing conditions including compost application and vinyl mulching on the maintenance of ridge and the growth of upland crops, three crops such as corn, soybean and sweet potato were experimented by using three or four cultivars of crops in the Saemangeum reclaimed tidal land. Average soil salinity before seeding was 2 dS $m^{-1}$, which was low enough for general upland crops to grow. However, high soil EC more than 16 dS $m^{-1}$ was observed in some parts of the experimented field. In the experiment, it was concluded that growth retardation and yield reduction of summer upland crops might be from severe erosion of ridge, soil compaction, flooding or wet soil condition and high salinity of some parts, and then these deteriorations were possibly improved for good crop growth and yield increase by compost application and vinyl mulching cultivation in the Saemangeum reclaimed tidal land.

• Journal of Korea Port Economic Association
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• v.29 no.4
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• pp.289-323
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• 2013

This study set out to estimate and compare benefits of damage in case of storm surge at the Masan Port by using two of the most representative methodologies used to estimate benefits in port disaster prevention facility construction, namely CVM(contingent valuation method), which estimates the values of non-market goods, and MD-FDA(multi-dimensional flood damage analysis), which had usually been implemented in flood or dam projects. The benefit estimation for 30 years of costs was 2.5689 trillion won for CVM and 2.9596 trillion won for MD-FDA, which indicates that there was no big difference in benefits among disaster prevention facilities. However, in-depth testing should follow to figure out whether MD-FDA can replace CVM, which has been tested with non-market goods, when estimating the benefits of disaster prevention facilities based on those findings.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.355-363
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• 2009

Double cropping system of oilseed crops introduced rape and castor bean was studied in the newly reclaimed tidal land of Korea. Surface soil EC to reach at 50% of growth reduction to the tallest height of crops was estimated $4dS\;m^{-1}$ for castor bean and $6dS\;m^{-1}$ for rape by logarithmic function. The castor bean cultivated during rainy summer much more suffered serious growth and yield reduction by flooding damage in the Hwaong and Yeonsangang reclaimed lands having low soil conductivity and finer textured soil than in the Iweon reclaimed land having higher soil conductivity and coarse sandy textured soil. Rape cultivated during dry winter-spring much more suffered serious growth and yield reduction by high soil salinity come from re-salting process. 50% yield reduction was estimated at $2.0\;2.5dS\;m^{-1}$ of surface soil EC by logarithmic function. Consequentially, it was concluded that oilseed production for energy by double cropping system of rape and castor bean might be possible under good controling soil salinity below $4dS\;m^{-1}$ for castor and $3dS\;m^{-1}$ for rape in the newly reclaimed land of Korea.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1435-1446
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• 2021

Wind and flood damage caused by typhoons causes a lot of damage to the Korean Peninsula every year. In order to minimize damage, a preliminary analysis of damage estimation and evacuation routes is required for rapid decision-making. This study attempted to develop an analysis module that can provide necessary information according to the disaster stage. For use in the preparation stage, A function to check past typhoon routes and past damage information similar to typhoon routes heading north, a function to extract isolated dangerous areas, and a function to extract reservoir collapse areas were developed. For use in the early stages of response and recovery, a function to extract the expected flooding range considering the current flooding depth, a function to analyze expected damage information on population, buildings, farmland, and a function to provide evacuation information were included. In addition, an automated web map creation method was proposed to express the analysis results. The analysis function was developed and modularized based on Python open source, and the web display function was implemented based on JavaScript. The tools developed in this study are expected to be efficiently used for rapid decision-making in the early stages of monitoring against storm and flood damage.

• 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.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.5
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• pp.253-264
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• 2019

Storm surges caused by a typhoon occur during the summer season, when the sea-level is higher than the annual average due to steric effect. In this study, we analyzed the sea-level pressure and tidal data collected in 1 h intervals at Incheon, Kunsan, Mokpo, Seogwipo stations on the Yellow Sea coast to analyze the summer season storm surge and wave overtopping. According to our analyses, the summer mean sea-level rise on the west and south coasts is approximately 20 cm and 15 to 20 cm higher than the annual mean sea-level rise. Changes in sea-level rise are closely related to changes in seasonal sea-level pressure, within the range of 1.58 to 1.73 cm/hPa. These correlated mechanisms generates a phase difference of one month or more. The 18.6 year long period tidal constituents indicate that in 2090, the amplitude of the $M_2$ basin peaks on the southwest coast. Therefore, there is a need to analyze the target year for global warming and sea-level rise in 2090. Wave overtopping was simulated considering annual mean sea-level rise, summer sea level rise, the combined effect of nodal factor variation, and 100-year frequency storm surge. As a result, flooding by wave overtopping occurs in the area of Suyong Bay, Busan. In 2090, overtopping discharges are more than doubled than those in Marine City by the recent typhoon Chaba. Adequate coastal design is needed to prepare for flood vulnerability.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.945-952
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• 2018

Recently, bass fishing has become a marine leisure sport in Korea. There are 4 major fishing associations in Korea, and each association holds 10-15 tournaments each year. However, supply of 17 ft bass boats, which are preferred in leagues, depends 100 % on imports. In this study, we have derived the main specifications to develop the initial hull forms of a 18.5ft bass boat through statistical analysis based on mothership data. In addition, CFD numerical analysis was carried out according to deadrise angle and longitudinal center of gravity, which strongly influenced the resistance and planing performance. For numerical analysis, design speed was set to $Fn=3.284 (Re=9.858{\times}10^7)$, the deadrise angle was set from 12 to $20^{\circ}$, and the longitudinal center of gravity was set in the range of 0 to $8%L_{wL}$ from the center of buoyancy to the stern. Based on the numerical results, we first set the range of these factors by resistance performance and immersion keel length. Furthermore, using a correlation graph of Savitsky's Drag-Lift ratio, we derived the deadrise angle ($14-16^{\circ}$) and longitudinal center of gravity ($4-6%L_{wL}$).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.141-150
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• 1992

Rapid change of urban area become a serious cause of disaster in existing drainage systems, and the practical alternatives in that situations are needed. The purpose of this study is to evaluate safety, one of drainage systems, detention reservoir and pumping station by new pumping criteria. New drainage pumping criteria, divided into two parts (rising limb and falling limb), which used in reservoir routing, shows more efficient flood prevention effect than existing criteria (based on the reservoir water level). To obtain the optimal range of flood prevention, sensitivity analysis of each inflow v.s. pumping capacity is tested. As a results, using 10 year design rainfall, 60% of detention reservoir and drainage pumping stations in Seoul are safe. In this results, there must be a fundamental and powerful counterplans to prevent inland flooding in Seoul metropolitan area.