• 한국농공학회논문집
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• 제62권2호
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• pp.1-15
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• 2020

In this study, the characteristics of crop damage area by flooding for 113 middle range watersheds during 2000-2016 were analyzed and future crop damage area by flooding were analyzed using 13 GCM outputs such as hourly maximum rainfall, 10-min maximum rainfall, number of days of 80 mm/day, daily rainfall maximum, annual rainfall amount associated with RCP 4.5 and RCP 8.5 scenarios and watershed characteristic data such as DEM, urbanization ratio, population density, asset density, road improvement ratio, river improvement ratio, drainage system improvement ratio, pumping capacity, detention basin capacity, and crop damage area by flooding. A constrained multiple linear regression model was used to construct the relationships between the crop damage area by flooding and other variables. Future flood index related to crop damage may mainly increase in the Mankyung watershed, Southwest part of Youngsan and Sumjin river basin and Southern part of Nackdong river basin. Results are useful to identify watersheds which need to establish strategies for responding to future flood damage.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.949-958
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• 2024

In contrast to all-time flooded small modular reactor (SMR) systems, an in-kind flooding safety system (FSS) has been proposed as a passive safety system applicable to small modular reactors (SMRs) that adopt a metal containment vessel (MCV). Under transient conditions, the FSS can provide emergency cooling to dry reactor cavities and sustain long-term coolability using re-acquired evaporated steam in the reactor building on demand. When designing an FSS, the effect of the flooding flow area is vital as it affects the overall accident sequence and safety. Therefore, in this study, a MELCOR model of a reference SMR is developed and numerical analysis is performed under postulated accident scenarios. Without flooding, the MCV pressure of the reactor module exceeds the design pressure before core damage. To prevent core damage, an emergency flooding strategy is devised using various flow path parameters and requirements to ensure an adequate emergency coolant supply before the core damage is investigated. The results indicate that a flow area exceeding 0.02 m2 is required in the FSS to prevent MCV overpressure and core damage. This study is the first to report a strategic analysis for appropriately sizing an FSS flooding valve applicable to innovative SMRs.

• 한국수자원학회논문집
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• 제51권1호
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• pp.1-10
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• 2018

최근 집중호우로 서울 강남구('12), 부산('13), 울산('16), 인천, 부산('17) 등 대도시 지역의 침수 피해가 증가하고 있다. 도시침수는 하천유역의 홍수 피해와는 달리 매우 짧은 시간에 피해가 발생하며, 시설물의 파괴보다는 주택, 차량, 상가 침수로 인한 재산 피해가 높은 비율을 차지하고 있다. 현재 우리나라의 호우에 대한 예 경보는 기상청에서 발표하는 호우 주의보 및 경보에 의존하고 있지만, 기상청의 호우 주의보 및 경보는 전국 공통 지표를 사용함으로써 지역적 특성을 반영하지 못하고 있는 실정이다. 따라서 본 연구에서는 서울과 울산지역을 대상으로 지역별로 피해이력기반의 한계강우량을 추정하였으며, 피해이력이 없어 한계강우량 추정이 불가능한 지역에 대해서는 유역특성이 반영된 Neuro-Fuzzy 모형을 통해 한계강우량을 예측하였다. 추정된 한계강우량을 통해 도시침수 위험기준을 설정하고 실제 침수사상에 적용한 결과 추정된 한계강우량은 실제 한계강우량과 1.8~20.4%의 오차를 보이고 있으며, 최소 28분에서 최대 70분의 대피시간을 확보 할 수 있는 것으로 나타났다. 따라서 도시침수 예 경보를 위한 위험기준으로 활용가능 할 것으로 판단된다.

• 한국농공학회지
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• 제11권3호
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• pp.1742-1748
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• 1969

This is a method to determine the boundary line of reservoir flooding area which will be purchased. Until now, flood water level was used as the boundary line. By lowering this line from flood water level, purchasing cost of reservoir flooding area can be cut down. Sometimes, temporary flooding of arable land outside the boundary occurs. During the life of reservoir, flood damage to crop product on of this land must be indemified with net berefit from arable land between the bovndary line and normal water level. Following is the basic formula to determine the line. (Estimated flood damage to crop production of land outside the boundary line $\leqq$ Estimated net beneift from land between the boundary line and normal water level.) Minimum difference between both sides is needed to minimize the purchasing area. Flood damage and net benefit are estimated by hydrologic estimation with rainfall data and crop production estimation.

• 한국산학기술학회논문지
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• 제20권4호
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• pp.545-550
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• 2019

전 세계적으로 발생하고 있는 이상기후현상으로 자연재해의 발생빈도와 피해규모가 증가하고 있는 추세이다. 이로 인하여 도시유역의 수문학적 양상이 변화함에 따라 불투수 면적 증가와 함께 증가된 호우로 심각한 내수침수 피해를 가져온다. 이에 인명 및 재산피해를 최소화하기 위하여 내수침수 예측체계가 필요하다. 본 연구에서는 강우강도와 지속시간만으로 침수예측이 가능한 Flood Nomogram을 개발하였다. 내수침수 발생가능이 매우 높고 침수 위험도가 높은 대도시내 침수예상 지역의 내수침수피해 특성을 분석하여 내수침수 예보 기준을 설정하는 방법을 제시하였다. 또한 우수맨홀과 우수관경을 기준으로 내수위를 4가지 조건하에 도시내수침수 예보 기준을 다음과 같이 설정하였다. 1) 우수맨홀이 넘칠 때, 2) 우수관경이 가득 찼을 때, 3) 우수관경의 70%에 도달했을 때, 그리고 4) 우수관경의 60%에 도달했을 경우이다. 따라서, 침수가 발생하기 시작하는 강우와 침수피해를 유발하는 강우사상을 통하여, 내수침수가 시작되기 전에 사전대비, 대응할 수 있는 기준과 예측하는 수단으로 활용할 수 있을 것으로 나타났다.

• 한국전자통신학회논문지
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• 제18권1호
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• pp.91-98
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• 2023

최근 국지성 폭우로 인한 침수 피해가 빈번하게 발생함에 따라 침수 피해를 사전 예방하기 위한 침수 예측 연구가 진행되고 있다. 본 논문에서는 머신 러닝 기반으로 강우 데이터를 이용해 침수 깊이와 침수 위치를 예측하는 모델을 개발하는 방법을 연구한다. 실시간 강우량을 입력으로 사용하여 다양한 강우 분포 패턴에 강건하게 구성하고 적은 메모리로 모델을 학습시킬 수 있는 2가지 데이터 셋(set) 구성 방법을 제시하였다. 침수에 유의미한 영향을 미치는 valid total 데이터는 침수 위치는 잘 예측했지만, 특정 강우 패턴에 대해 값이 다르게 나타나는 경향을 띠었다. 부분적이지만 침수에 영향을 미치는 영역을 valid local이라 한다. Valid local은 고정점 방법에 대해서는 잘 학습되었지만, 임의점 방법에 대해서는 침수 위치를 정확하게 나타내지 못했다. 본 연구를 통해 실시간으로 침수 깊이와 위치를 예측할 수 있게 되어 큰 피해를 예방할 수 있을 것으로 예상된다.

• 한국작물학회지
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• 제44권1호
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• pp.38-43
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• 1999

Over 2,000 ha of rice fields in the western and southern coastal region of Korea were flooded with sea water during the spring tide, on August 19-21, 1997, and the rice plant at heading stage was injured. The field surveys were undertaken at the sea water flooded paddy fields in Chonbuk Province, to identify the injury symptoms and rice yield damage subjected to different flooding condition and desalinization methods. Five days after sea water flooding at heading stage, the flag leaves of rice plants flooded with 30 ㎝ deep sea water withered from the tip, the withering progressed to the lower leaves in deeper flooding. The spikelets were spotted black and discolored from the tip at 50 ㎝ deep flooded rice, and some panicles changed to white at 80 ㎝ deep flooded rice. Most of the rice leaves submerged completely for an hour were withered and most of panicles changed to white. The milled rice yield, percentage of ripened grain, and 1000 grain weight of flooded rice decreased with deeper flooding water, higher water salinity and longer flooding time. Even under the same flooding conditions, the damage of rice yield varied with the growth stage: heading stage>dough stage>booting stage. Rice yield damage was less in the fields on the upper riverside than those of the fields on the estuary and seaside, because of lower water salinity. In a flooded field, the rice yield damages were reduced as the distance increased from the levees where the sea water inflowed and increased as the distance increased from the fresh water irrigation gate. The desalinization treatments consisting of frequent exchange of irrigation water and spraying with fresh water soon after flooding effectively reduced the rice yield damage.

• 대한조선학회논문집
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• 제43권1호
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• pp.1-14
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• 2006

To improve maritime safety, it is very important not only to make safer design and operation but also to do proper response in case of maritime casualty. The large-scaled casualties will be caused by loss of structural strength and stability due to the progressive flooding and enlargement of damage by the effect of waves and wind. To prevent foundering and structural failure, the prediction of ship motion behavior of damaged ship in wave is necessary. This paper describes the motion behavior of damaged ship in waves through theoretical and experimental studies. A time domain theoretical model of damaged ship motions and accidental flooding, which can be applied to any type of ship or arrangement and considers the effects of flooding of compartments, has been developed. The model tests have been carried out in regular and irregular waves with different wave heights and directions in ship motion basin. Those were performed for three different damaged conditions such as engine room bottom damage, side shell damage and bow visor damage of a Ro-Ro ship. Comparison of theoretical and experimental results was performed.

• 한국농공학회지
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• 제24권4호
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• pp.69-79
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• 1982

The objective of this study is to contribute to drainage planning in the most realistic and economical way by establishing the relationship between rice yield reduction and overhead flooding by muddy water of each growth stage of paddy, which is the most important factor in determining optimum drainage facilities. This study was based on the data mainly from the experimental reports of the Office of Rural Development of Korea, Reduction Rate Estimation for Summer Crops, published by Ministry of Agriculture and Forestry of Japan and other related research documenta- tion. The results of this study are summarized as follows 1. Damages by overhead flooding are highest in heading stage and have the tendency of decrease in the order of booting stage, panicle formation stage, tillering stage, and stage just after transplanting. Damages by overhead flooding of each growing stage are as follows: a) It is considered that overhead flooding just after transplanting gives a little influence on plant growth and yield because the paddy has sufficient growth period from floo ding to harvest time. b) Jt is analyzed that according to the equation y=11 12x 0.908 which is derived from this study, damages by overhead flooding during tillering stage for 1, 2, 3 successive days are 11.1 %, 20.9%, and 30.2% respectively. c) Damages by overhead flooding after panicle formation stage are very serious because recovering period is very short after damage and ineffective tillering is much. Acc- ording to the equation y=9. 58x+10. Ol derived from this study, damages by overhead flooding fal 1,2,3,5 successive days are 19.6%, 29.2%, 38.8%, 57.9% respectively. d) Booting stage is the very important period in which young panicle has grown up almost completely and the number of glumous flower is fixed since reduction division takes place in the microspore mother cell and enbryo mother cell. According to the equation y=39. 66x 0.558 derived from this study, damages by overhead floodingfor 0.5, 1, 3, 5 successive days are 26.9%, 39.7%, 72. 2% and 97.4%, respectively. Therefore, damages by overhead flooding is very serious during the hooting stage. e) When ear of paddy emerges, flowering begins on that day or the next day; when paddy flowers, fertilization will be completed 2-3 hours after flowering. Therefore overhead flooding during heading stage impedes flowering and increases sterilizing percentage. From this reason damages of heading stage are larger than that of booting stage. According to the equation y-41 94x 0.589 derived from this study, damages by overhead flooding for 0.5, 1, 3, 5, successive days are 27.9%, 63.1 %, 80.1%, and 100% 2. Considering that temperature of booting stage is higher than that of beading stage and plant height of booting stage is ten centimeters shorter than that of heading stage, booting stage should be taken as a critical period for drainage planning because possi- bility of damage occurrence in booting stage is larger than that of heading stage. There-fore, it is considered that booting stage should be taken as critical period of paddy growth for drainage planning. 3. Overhead flooding depth is different depending on the stage of growth. In case, booting stage is adopted as design stage of growth for drainage planning, it is conside red that the allowable flooding depth for new varieties and general varieties are 70cm and 80cm respectively. 4. Reduction Rate Estimation by Wind and Flood for Rice Planting of the present design criteria for drainage planning shows damage by overhead flooding for 1 to 2, 3 to 4, 5 to 7 consecutive days; damages by overhead flooding varies considerably over several hours and experimental condition of soil, variety of paddy, and climate differs with real situation. From these reasons, damage by flooding could not be estimated properly in the past. This study has derived the equation which shows damages by flooding of each growth stage on an hourly basis. Therefore, it has become possible to compute the exact damages in case duration of overhead flooding is known.

• Environmental Engineering Research
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• 제22권4호
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• pp.393-400
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• 2017

One of the big problems facing municipalities is the management and control of urban flooding where urban drainage systems are under growing pressure due to increases in urbanization, population and changes in the climate. Urban flooding causes environmental and infrastructure damage, especially to roads, this damage increasing maintenance costs. The aim of the present study is to develop a decision support tool to identify the performance of storm networks to address future risks associated with climate change in the Middle East region and specifically, illegal sewer connections in the storm networks of Karbala city, Iraq. The storm water management model has been used to simulate Karbala's storm drainage network using continuous hourly rainfall intensity data from 2008 to 2016. The results indicate that the system is sufficient as designed before consideration of extra sewage due to an illegal sewer connection. Due to climate changes in recent years, rainfall intensity has increased reaching 33.54 mm/h, this change led to flooding in 47% of manholes. Illegal sewage will increase flooding in the storm system at this rainfall intensity from between 39% to 52%.