• Title/Summary/Keyword: Flooding Area

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Analysis on Rainwater Harvesting System as a Source of Non-Potable Water for Flood Mitigation in Metro Manila (마닐라의 홍수저감을 위한 잡용수 대체자원으로서의 가정용우수저류시설 분석)

  • Necesito, Imee V.;Felix, Micah Lourdes A.;Kim, Lee-Hyung;Cheong, Tae Sung;Jeong, Sangman
    • Journal of Wetlands Research
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    • v.15 no.2
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    • pp.223-231
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    • 2013
  • Excessive precipitation, drought, heat waves, strong typhoons and rising sea levels are just some of the common indicators of climate change. In the Philippines, excessive precipitation never failed to devastate and drown the streets of Metro Manila, a highly urbanized and flood-prone area; such problems are expected to occur frequently. Moreover, the water supply of Metro Manila is dependent only to Angat Reservoir. Rainwater harvesting can serve as an alternative source of raw water and it can mitigate the effects of flooding. The harvested rainwater can be used for: potable consumption if filtered and disinfected; and non-potable consumptions (e.g., irrigation, flushing toilets, carwash, gardening, etc.) if used untreated. The rainfall data were gathered from all 5 rainfall stations located in Metro Manila namely: Science Garden, Port Area, Polo, Nangka and Napindan rain gauge stations. To be able to determine the potential volume of rainwater harvested and the potentiality of rainwater harvesting system as an alternate source of raw water; in this study, three different climatic conditions were considered, the dry, median and wet rainfall years. The frequent occurrence of cyclonic events in the Philippines brought significant amount of rainwater that causes flooding in the highly urbanized region of Metro Manila. Based from the results of this study, the utilization of rainwater harvesting system can serve as an alternative source of non-potable water for the community; and could also reduce the amount of surface runoff that could result to extreme flooding.

A Study on Flooding Characteristic Value for the Decision Method of an Urban Basin Design Magnitude (도시유역의 치수계획규모 결정을 위한 침수특성치에 관한 연구)

  • Ahn, Jeonghwan;Cho, Woncheol;Kim, Hosoung
    • Journal of Korea Water Resources Association
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    • v.45 no.10
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    • pp.1035-1041
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    • 2012
  • This paper is on the decision of design magnitude for flood control of urban basin, based on flooding characteristic values. In Korea, a design magnitude for flood control is established based on peak discharge of the outlet of basin. However, this method is inappropriate in an urban basin because sewerage only can flow out as much as it could and other discharge overflow to basin. In order to calculate a design magnitude for flood control of an urban basin, flooding characteristic values (peak discharge of pipe, average flooded depth, maximum flooded depths of an important point, flooded area, flooded volume, flooded time) were used as a tool. Using the Gwanghwamun Square as an example, a methodology was proposed that used XP-SWMM 2010 model as a platform to predict urban flood disaster. It can help other local government and residents to better understand, prepare for and manage a flood in urban environments.

Study of Plans for a Residential Area for Displaced Villagers Considering Sustainability: A Case of Gyodong-village, Pocheon-si, Gyeonggi-do in Korea (지속가능성을 고려한 농촌마을 이주단지 조성계획 연구 -경기도 포천시 교동마을을 대상으로-)

  • Joo, Myoung-Gyu;Cho, Joong-Hyun
    • Journal of Korean Society of Rural Planning
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    • v.18 no.3
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    • pp.175-186
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    • 2012
  • This is a study of a residential area for displaced villagers planned for residents of Gyodo Village who must evacuate their hometown because of flooding due to the Hantan River Dam Project. The study aims to construct a plan for a new residential area for the villagers focusing on reflecting the existing characteristics of their former village and on ensuring sustainability for the new village. Departing from previous practice of focusing on merely physical aspects when planning, the current study is significant in that it presents a new planning process and method for a sustainability-focused plan. While the study has many limitations such as objectivity in the process of deriving the sustainability indicators and the appropriateness of the indicator questions, it is hoped that future studies on sustainability will serve to make up for these limitations and problems.

A Study on determining Flood Protection Elevation in Urban Area (도시지역 방어침수위 설정에 관한 연구)

  • Shin, Sang-Young;Lee, Yang-Jae
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.649-652
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    • 2008
  • In urban area, flood risk is getting higher because of inland flood risk has grown up by changing rainfall intensity, rainfall pattern, changing land use and so on. Urban area is needed higher flood protection level to protect accumulated people, buildings and other infrastructures. However, even though former flood protection has focused on overflow from river, there is not a guide line for evaluating proper flood protection level. Thus, it is necessary to protect flood from inland flooding as well as overflow from river and need a proper method to evaluating flood protection level. This study present a method of determining flood protection elevation by using GIS tools for deciding proper flood protection level. The study result may contribute to urban flood protection measures in which inland flood risk increases.

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A Study on Making Map of Flood Using Digital Elevation Model (DEM) (수치표고모형 (DEM)을 이용한 침수재해 지도작성에 관한 연구)

  • Lim, Hyun Taek;Kim, Jae Hwi;Lee, Hak Beom;Park, Sung Yong;Kim, Yong Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.2
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    • pp.81-90
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    • 2017
  • Recent floodplain data are important for river master plan, storm and flood damage reduction comprehensive plan and pre-disaster impact assessment. Hazard map, base of floodplain data, is being emphasized as important method of non-structural flood prevention and consist of inundation trace map, inundation expected map and hazard information map. Inundation trace map describes distribution of area that damaged from typhoons, heavy rain and tsunamis and includes identified flood level, flood depth and flood time from flooding area. However due to lack of these data by local government, which are foundational and supposed to be well prepared nationwide, having hard time for making inundation trace map or hazard information map. To overcome this problem, time consumption and budget reduction is required through various research. From this study, DEM (Digital Elevation Model) from image material from UAVS (Unmanned Aerial Vehicle System) and numeric geographic map from National Geographic Information Institute are used for calculating flooding damaged area and compared with inundation trace map. As results, inundation trace map DEM based on image material from UAVS had better accuracy than that used DEM based on numeric geographic map. And making hazard map could be easier and more accurate by utilizing image material from UAVS than before.

Numerical Study on Comparison of Serpentine and Parallel Flow Channel in High-temperature Proton Exchange Membrane Fuel Cells (고온형 고분자전해질형 연료전지에서의 사형 유로와 평행 유로 성능비교에 대한 수치해석적 연구)

  • AHN, SUNGHA;OH, KYEONGMIN;JU, HYUNCHUL
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.1
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    • pp.41-55
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    • 2018
  • General polymer electrolyte fuel cell (PEMFC) operates at less than $80^{\circ}C$. Therefore liquid phase water resulting from electrochemical reaction accumulates and floods the cell which in turn increases the mass transfer loss. To prevent the flooding, it is common to employ serpentine flow channel, which can efficiently export liquid phase water to the outlet. The major drawback of utilizing serpentine flow channel is the large pressure drop that happens between the inlet and outlet. On the other hand, in the high temperature polymer electrolyte fuel cell (HT-PEMFC), since the operating temperature is 130 to $180^{\circ}C$, the generated water is in the state of gas, so the flooding phenomenon is not taken into consideration. In HT-PEMFCs parallel flow channel with lower pressure drop between the inlet and outlet is employed therefore, in order to circulate hydrogen and air in the cell less pumping power is required. In this study we analyzed HT-PEMFC's different flow channels by parallel computation using previously developed 3-D isothermal model. All the flow channels had an active area of $25cm^2$. Also, we numerically compared the performance of HT-PEMFC parallel flow channel with different manifold area and Rib interval against the original serpentine flow channel. Results of the analysis are shown in the form of three-dimensional contour polarization curves, flow characteristics in the channel, current density distribution in the Membrane, overpotential distribution in the catalyst layer, and hydrogen and oxygen concentration distribution. As a result, the performance of a real area fuel cell was predicted.

Analysis of Flood Inundated Area Using Multitemporal Satellite Synthetic Aperture Radar (SAR) Imagery (시계열 위성레이더 영상을 이용한 침수지 조사)

  • Lee, Gyu-Seong;Kim, Yang-Su;Lee, Seon-Il
    • Journal of Korea Water Resources Association
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    • v.33 no.4
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    • pp.427-435
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    • 2000
  • It is often crucial to obtain a map of flood inundated area with more accurate and rapid manner. This study attempts to evaluate the potential of satellite synthetic aperture radar (SAR) data for mapping of flood inundated area in Imjin river basin. Multitemporal RADARSAT SAR data of three different dates were obtained at the time of flooding on August 4 and before and after the flooding. Once the data sets were geometrically corrected and preprocessed, the temporal characteristics of relative radar backscattering were analyzed. By comparing the radar backscattering of several surface features, it was clear that the flooded rice paddy showed the distinctive temporal pattern of radar response. Flooded rice paddy showed significantly lower radar signal while the normally growing rice paddy show high radar returns, which also could be easily interpreted from the color composite imagery. In addition to delineating the flooded rice fields, the multitemporal radar imagery also allow us to distinguish the afterward condition of once-flooded rice field.

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A review of ground camera-based computer vision techniques for flood management

  • Sanghoon Jun;Hyewoon Jang;Seungjun Kim;Jong-Sub Lee;Donghwi Jung
    • Computers and Concrete
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    • v.33 no.4
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    • pp.425-443
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    • 2024
  • Floods are among the most common natural hazards in urban areas. To mitigate the problems caused by flooding, unstructured data such as images and videos collected from closed circuit televisions (CCTVs) or unmanned aerial vehicles (UAVs) have been examined for flood management (FM). Many computer vision (CV) techniques have been widely adopted to analyze imagery data. Although some papers have reviewed recent CV approaches that utilize UAV images or remote sensing data, less effort has been devoted to studies that have focused on CCTV data. In addition, few studies have distinguished between the main research objectives of CV techniques (e.g., flood depth and flooded area) for a comprehensive understanding of the current status and trends of CV applications for each FM research topic. Thus, this paper provides a comprehensive review of the literature that proposes CV techniques for aspects of FM using ground camera (e.g., CCTV) data. Research topics are classified into four categories: flood depth, flood detection, flooded area, and surface water velocity. These application areas are subdivided into three types: urban, river and stream, and experimental. The adopted CV techniques are summarized for each research topic and application area. The primary goal of this review is to provide guidance for researchers who plan to design a CV model for specific purposes such as flood-depth estimation. Researchers should be able to draw on this review to construct an appropriate CV model for any FM purpose.

Position-Dependent Cathode Degradation of Large Scale Membrane Electrode Assembly for Direct Methanol Fuel Cell (직접 메탄올 연료전지용 대면적 막-전극 접합체 공기극의 위치별 열화 현상)

  • Kim, Soo-Kil;Lee, Eun-Sook;Kim, Yi-Young;Kim, Jang-Mi;Joh, Han-Ik;Ha, Heung-Yong
    • Journal of the Korean Electrochemical Society
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    • v.12 no.2
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    • pp.148-154
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    • 2009
  • With respect to the durability of large scale ($150cm^2$) membrane electrode assembly (MEA) of direct methanol fuel cell (DMFC), degradation phenomena at cathode is monitored and analyzed according to the position on the cathode surface. After constant current mode operation of large scale MEA for 500 hr, the MEA is divided into three parts along the cathode channel; (close to) inlet, middle, and (close to) outlet. The performance of each MEA is tested and it is revealed that the MEA from the cathode outlet of large MEA shows the worst performance. This is due to the catalyst degradation and GDL delamination caused by flooding at cathode outlet of large MEA during the 500 hr operation. Particularly on the catalyst degradation, the loss of electrochemically active surface area (ECSA) of catalyst gets worse along the cathode channel from inlet to outlet, of which the reason is believed to be loss of catalysts by dissolution and migration rather than their agglomeration. The extent of loss in the performance and catalyst degradation has strong relation to the cathode flooding and it is required to develop proper water management techniques and separator channel design to control the flooding.

The Proposal of Evaluation Method for Local Government Infrastructure Vulnerability Relating to Climate Change Driven Flood (기후변화에 따른 홍수에 대한 지자체 기반시설 취약성 평가 방법 제시)

  • Han, Woo Suk;Sim, Ou Bae;Lee, Byoung Jae;Yoo, Jae Hwan
    • Journal of Climate Change Research
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    • v.3 no.1
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    • pp.25-37
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    • 2012
  • This research proposes the direction for the assessment of local government infrastructure vulnerabilities relating to climate change driven flood and analyzes the assessment result. In this research, the local government infrastructures are evaluated by three indices such as exposure, infrastructure sensitivity, adaptive capacity and each index is calculated by selected alternative variable. Climate change scenario(A1B) developed on National Institute of Environmental Research is used to calculate present and future(2020, 2050, 2100s) exposure. As the result of infrastructure vulnerability assessment on present, the infrastructures in Seoul, Northern Gyeonggi-do, Gangwon-do, coastal area of Gyeongsangnam-do are vulnerable to flooding. For future, although the spatial pattern of flooding vulnerable infrastructure are similar, the flooding vulnerabilities of infrastructure in Gyeonggido and Ganwon-do would be increased as close to 2100s. It is expected that this research can be utilized as the preliminary analysis for climate change adaptation in local government infrastructure because this research propose the method for the assessment of local government infrastructure vulnerability relating to climate change driven flood and the result such as a trend of infrastructure vulnerability to flooding and the level of contribution of each index and alternative variable.