• Title/Summary/Keyword: flood mapping

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Mapping Inundation Areas by Flash Flood and Developing Rainfall Standards for Evacuation in Urban Settings (GIS를 이용한 도시지역 돌발홍수 침수예상지도 작성 및 대피강우기준 개발)

  • Shin, Sang-Young;Yeo, Chang-Geon;Baek, Chang-Hyun;Kim, Yoon-Jong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.4
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    • pp.71-80
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    • 2005
  • As local flash flood exceeding planned capacity occurs frequently, localized preparedness and response to flood inundation are increasingly important. Using XP-SWMM model and GIS techniques, this study analyzes inundation areas by local flash flood and develops rainfall standards for evacuation with the case of Sadang-Cheon area, a local stream and its nearby highly populated watershed in the southern part of metropolitan Seoul, Flood inundation areas overflowed from drainage systems are analyzed and mapped by amount of rainfall that is derived from reference levels of stream flow. Rainfall standards for evacuation are comprised of 'watch' (40mm/hr) in preparing for near-future inundation and 'evacuation' (65mm/hr) in responding to realized inundation. The methods suggested by this case study may be applied to other urban areas for sound flood prevention policy measures and thus risk minimization.

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A review of rotorcraft Unmanned Aerial Vehicle (UAV) developments and applications in civil engineering

  • Liu, Peter;Chen, Albert Y.;Huang, Yin-Nan;Han, Jen-Yu;Lai, Jihn-Sung;Kang, Shih-Chung;Wu, Tzong-Hann;Wen, Ming-Chang;Tsai, Meng-Han
    • Smart Structures and Systems
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    • v.13 no.6
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    • pp.1065-1094
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    • 2014
  • Civil engineers always face the challenge of uncertainty in planning, building, and maintaining infrastructure. These works rely heavily on a variety of surveying and monitoring techniques. Unmanned aerial vehicles (UAVs) are an effective approach to obtain information from an additional view, and potentially bring significant benefits to civil engineering. This paper gives an overview of the state of UAV developments and their possible applications in civil engineering. The paper begins with an introduction to UAV hardware, software, and control methodologies. It also reviews the latest developments in technologies related to UAVs, such as control theories, navigation methods, and image processing. Finally, the paper concludes with a summary of the potential applications of UAV to seismic risk assessment, transportation, disaster response, construction management, surveying and mapping, and flood monitoring and assessment.

A Review on Remote Sensing and GIS Applications to Monitor Natural Disasters in Indonesia

  • Hakim, Wahyu Luqmanul;Lee, Chang-Wook
    • Korean Journal of Remote Sensing
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    • v.36 no.6_1
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    • pp.1303-1322
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    • 2020
  • Indonesia is more prone to natural disasters due to its geological condition under the three main plates, making Indonesia experience frequent seismic activity, causing earthquakes, volcanic eruption, and tsunami. Those disasters could lead to other disasters such as landslides, floods, land subsidence, and coastal inundation. Monitoring those disasters could be essential to predict and prevent damage to the environment. We reviewed the application of remote sensing and Geographic Information System (GIS) for detecting natural disasters in the case of Indonesia, based on 43 articles. The remote sensing and GIS method will be focused on InSAR techniques, image classification, and susceptibility mapping. InSAR method has been used to monitor natural disasters affecting the deformation of the earth's surface in Indonesia, such as earthquakes, volcanic activity, and land subsidence. Monitoring landslides in Indonesia using InSAR techniques has not been found in many studies; hence it is crucial to monitor the unstable slope that leads to a landslide. Image classification techniques have been used to monitor pre-and post-natural disasters in Indonesia, such as earthquakes, tsunami, forest fires, and volcano eruptions. It has a lack of studies about the classification of flood damage in Indonesia. However, flood mapping was found in susceptibility maps, as many studies about the landslide susceptibility map in Indonesia have been conducted. However, a land subsidence susceptibility map was the one subject to be studied more to decrease land subsidence damage, considering many reported cases found about land subsidence frequently occur in several cities in Indonesia.

Development of Probabilistic Flood Risk Map Considering Uncertainty of Levee Break (하천제방 붕괴의 불확실성을 고려한 확률론적 홍수위험지도 개발)

  • Nam, Myeong-Jun;Lee, Jae-Young;Lee, Chang-Hee
    • Journal of Convergence for Information Technology
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    • v.9 no.11
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    • pp.125-133
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    • 2019
  • In this paper, probabilistic flood risk maps were produced for levee break caused by possible flood scenarios. The results of the previous studies were employed for flood stages corresponding to hydrological extreme event quantified uncertainties and then predicted the location of a levee breach. The breach width was estimated by combining empirical equation considered constant width and numerical modeling considered uncertainties on compound geotechnical component. Accordingly, probabilistic breach outflow was computed and probabilistic inundation map was produced by 100 runs of 2D inundation simulation based on reliability analysis. The final probabilistic flood risk map was produced by combining probabilistic inundation map based on flood hazard mapping methodology. The outcomes of the study would be effective in establishing specified emergency actin plan (EAP) and expect to suggest more economical and stable design index.

A Study on Effective Flood Map Generation using NGIS Digital Topographic Maps (효율적인 홍수지도 구축을 위한 NGIS 수치지형도 활용에 관한 연구)

  • 송용철;권오준;김계현
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.04a
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    • pp.449-454
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    • 2004
  • Nowadays, flood hazard maps have been generated to minimize the loss of human lives due to flooding domestically. To generate the flood hazard maps, LiDAR data have mainly been used to provide topographic data. The LiDAR data requires, however, relatively higher cost and processing time. Therefore, the needs of validating possible use of topographic maps as an alternative source of LiDAR, which have been already existed from the NGIS project over the nation, has been raised. In this background, this study has generated a DEM over City of Kuri as a pilot study using conventional 1:1,000 and 1:5,000 topographic maps emphasizing the linkage of river profile with breakline processing algorithm to build the essential topographic data as accurate as possible. The results showed that the RMSE from topographic maps and LiDAR were 3.49 and 2.282 meter, respectively. Further study needs to be made to decide possible use of topographic maps instead of LiDAR including more easier updating of topographic maps to support flood map generation. In addition, 1:1,000 topographic mapping, which is limited to the urban areas so far, needs to be extended to the river areas.

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A Study on the Inundation Analysis of the Nam River Lowland Using GIS and FLUMAN (GIS와 FLUMAN을 이용한 남강 저지대 침수분석에 관한 연구)

  • Choi, Hyun
    • Journal of Korean Society for Geospatial Information Science
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    • v.25 no.2
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    • pp.49-56
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    • 2017
  • In this study, flood analysis was conducted to prepare for damage caused by typhoons and heavy rain due to abnormal climate and climate change. Two - dimensional flooding analysis using the FLUMEN model, which is widely used for national and international flood risk mapping, was conducted for the Nam River Basin, which is the tributary of the Nakdong River. This study divides the topography into $5m{\times}5m$ DEM by ArcView, so that the accuracy of river repair and hydrological characterization and flood area identification can be maximized. As a result of simulation of water flooding, 163.3ha in section 1, 227.7ha in section 2 and 59.9ha in section 3 were simulated.

The Construction of GIS-based Flood Risk Area Layer Considering River Bight (하천 만곡부를 고려한 GIS 기반 침수지역 레이어 구축)

  • Lee, Geun-Sang;Yu, Byeong-Hyeok;Park, Jin-Hyeog;Lee, Eul-Rae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.12 no.1
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    • pp.1-11
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    • 2009
  • Rapid visualization of flood area of downstream according to the dam effluent in flood season is very important in dam management works. Overlay zone of river bight should be removed to represent flood area efficiently based on flood stage which was modeled in river channels. This study applied drainage enforcement algorithm to visualize flood area considering river bight by coupling Coordinate Operation System for Flood control In Multi-reservoir (COSFIM) and Flood Wave routing model (FLDWAV). The drainage enforcement algorithm is a kind of interpolation which gives to advantage into hydrological process studies by removing spurious sinks of terrain in automatic drainage algorithm. This study presented mapping technique of flood area layer considering river bight in Namgang-Dam downstream, and developed system based on Arcobject component to execute this process automatically. Automatic extraction system of flood area layer could save time-consuming efficiently in flood inundation visualization work which was propelled based on large volume data. Also, flood area layer by coupling with IKONOS satellite image presented real information in flood disaster works.

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Real-Time Forecast of Rainfall Impact on Urban Inundation (강우자료와 연계한 도시 침수지역의 사전 영향예보)

  • KEUM, Ho-Jun;KIM, Hyun-Il;HAN, Kun-Yeun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.3
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    • pp.76-92
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    • 2018
  • This study aimed to establish database of rainfall inundation area by rainfall scenarios and conduct a real time prediction for urban flood mitigation. the data leaded model was developed for the mapping of inundated area with rainfall forecast data provided by korea meteorological agency. for the construction of data leaded model, 1d-2d modeling was applied to Gangnam area, where suffered from severe flooding event including september, 2010. 1d-2d analysis result agree with observed in term of flood depth. flood area and flood occurring report which maintained by NDMS(national disaster management system). The fitness ratio of the NDMS reporting point and 2D flood analysis results was revealed to be 69.5%. Flood forecast chart was created using pre-flooding database. It was analyzed to have 70.3% of fitness in case of flood forecast chart of 70mm, and 72.0% in case of 80mm flood forecast chart. Using the constructed pre-flood area database, it is possible to present flood forecast chart information with rainfall forecast, and it can be used to secure the leading time during flood predictions and warning.

Identification of Flooded Areas and Post-flooding Conditions: Developing Flood Damage Mitigation Strategies Using Satellite Radar Imagery (레이더 위성영상을 활용한 침수피해 지역 파악 및 완화방안 연구)

  • Lee, Moungjin;Myeong, Soojeong;Jeon, Seongwoo;Won, Joong-Sun
    • Journal of Environmental Policy
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    • v.8 no.2
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    • pp.1-23
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    • 2009
  • This study applied satellite radar imagery to identify flooded areas and examined post-flooding conditions using time-series satellite radar imagery for the development of flood damage mitigation strategies. Using time-series satellite radar images, this study constructed a map delineating areas vulnerable to frequent flood damage. The extracted flooded areas were combined with reference land use maps to examine flood damage by land use type. Major landuse types with severe flood damage were agricultural and forested areas. The analysis of the damage conditions, in terms of land use, served as the basis for developing flood damage mitigation policies, in conjunction with land use planning. The policies for flood damage mitigation can be summarized as land use regulations, land use planning, and flood damage mapping. A preventive measure to minimize flood damage of properties, which regulates developing areas with high flooding potential, is highly recommended. Although this study suggested a number of policies for flood damage mitigation, they represent only a small number of possible policies useful for mitigating flood damage and other environmental problems. Based upon the results of this study, it may be concluded that satellite radar imagery has great potential in providing basic data for large-scale environmental problems such as flooding and oil spills. Nevertheless, further examinations should be conducted and the application of satellite radar imagery should be used to examine other environmental problems.

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