• Title/Summary/Keyword: Flooding Area

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Inplementation of flooding simulation in coastal area based on 3D satellite images and Web GIS

  • Jo, Myung-Hee;Park, Hyeon-Cheol;Kim, Hyoung-Sub;Choi, Yong-Ki
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.166-169
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    • 2006
  • Our country's coast is vulnerable area to natural disaster which the repetitive damages occur every year including a loss of lives, the damage of facilities and erosion mostly except for the east coast because of a typhoon, tidal waves, sea water overflowing by topographic structure of low-lying gentle slope and shallow sea. However, as for prevention of natural disaster occurring every year, the situation is that it's centered on the restorationcentered measures and the general disaster prevention research to minimize damages at the time of disaster occurrence is insufficient. This study intendedlop t to devehe techniques possible for real time sampling of damage prediction areas on Web in order to support decision making for damage prevention and establishment of disaster prevention policy. For this, the thematic map was produced related to disaster based on high-resolution satellite picture, and the environmental DB similar to real world was constructed through topographic construction of three-dimension integrating the parts of land and the sea. In addition, the system was developed possible for the expression of damageable regions by real time grasp of dangerous regions at the time of disaster occurrence through over flowing simulation of three-dimension, and it's intended to prepare a basis to minimize damages to disaster situations through it.

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A study of aerodynamic pressures on elevated houses

  • Abdelfatah, Nourhan;Elawady, Amal;Irwin, Peter;Chowdhury, Arindam
    • Wind and Structures
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    • v.31 no.4
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    • pp.335-350
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    • 2020
  • In coastal residential communities, especially along the coastline, flooding is a frequent natural hazard that impacts the area. To reduce the adverse effects of flooding, it is recommended to elevate coastal buildings to a certain safe level. However, post storm damage assessment has revealed severe damages sustained by elevated buildings' components such as roofs, walls, and floors. By elevating a structure and creating air gap underneath the floor, the wind velocity increases and the aerodynamics change. This results in varying wind loading and pressure distribution that are different from their slab on grade counterparts. To fill the current knowledge gap, a large-scale aerodynamic wind testing was conducted at the Wall of Wind experimental facility to evaluate the wind pressure distribution over the surfaces of a low-rise gable roof single-story elevated house. The study considered three different stilt heights. This paper presents the observed changes in local and area averaged peak pressure coefficients for the building surfaces of the studied cases. The aerodynamics of the elevated structures are explained. Comparisons are done with ASCE 7-16 and AS/NZS 1170.2 wind loading standards. For the floor surface, the study suggests a wind pressure zoning and pressure coefficients for each stilt height.

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.

Extraction of water body in before and after images of flood using Mahalanobis distance-based spectral analysis

  • Ye, Chul-Soo
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.293-302
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    • 2015
  • Water body extraction is significant for flood disaster monitoring using satellite imagery. Conventional methods have focused on finding an index, which highlights water body and suppresses non-water body such as vegetation or soil area. The Normalized Difference Water Index (NDWI) is typically used to extract water body from satellite images. The drawback of NDWI, however, is that some man-made objects in built-up areas have NDWI values similar to water body. The objective of this paper is to propose a new method that could extract correctly water body with built-up areas in before and after images of flood. We first create a two-element feature vector consisting of NDWI and a Near InfRared band (NIR) and then select a training site on water body area. After computing the mean vector and the covariance matrix of the training site, we classify each pixel into water body based on Mahalanobis distance. We also register before and after images of flood using outlier removal and triangulation-based local transformation. We finally create a change map by combining the before-flooding water body and after-flooding water body. The experimental results show that the overall accuracy and Kappa coefficient of the proposed method were 97.25% and 94.14%, respectively, while those of the NDWI method were 89.5% and 69.6%, respectively.

A Study on the Flood Damage Assessment by Typhoon RUSA in the East Coast of Kangwon Prefecture Following the 2000 Large Scale Fire Disaster -Focused on the Watershed of Oship River, Samcheok City (2000년 강원도 동해안지역 대규모 산불화재가 태풍루사 홍수피해에 미친 영향 -삼척시 오십천을 중심으로)

  • 강상혁
    • Fire Science and Engineering
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    • v.17 no.4
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    • pp.70-75
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    • 2003
  • The east coast of Kangwon province has been suffering from natural disaster like wildfire and flooding. In April 2000, there has been a great wildfire in this area. Many forest was burnt out, the mountain was bared. Furthermore, on 31st August,2002 typhoon RUSA attacked the area with heavy rainfall of about 315 mm/day, which resulted in 178 deaths and extensive damage to the property, In this regard, our study was focused on the assessment of the factors of flooding damage considering wildfire disaster. Most of results for our study are derived from practical investigation in the east coast of Kangwon province.

A study of Mesoscale Convective Systems(MCSs) event impacts on the safe operation of aircraft(I) (항공기 안전 운항에 영향을 미치는 중규모 대류계 사례 연구(I))

  • Kim, Young-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.22 no.1
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    • pp.76-84
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    • 2014
  • Heavy Rainfall event accompanying with Mesoscale Convective Systems(MCSs) inducing flash flooding and Kimpo and Inchon International Airport closing over Seoul metropolitan area was investigated this study. This heavy rainfall event was occurred through the synoptic scale boundary of North Pacific Subtropical high, Typhoon and also can predicted by proper analysis of various forecasting parameters such as abundant moisture, instabilities, and synoptic/mesoscale forcing.

Development of CREAMS-PADDY Model for Simulating Pollutants from Irrigated Paddies (관개 논에서의 영양물질 추정 모형의 개발)

  • 서춘석;박승우;김상민;강문성;임상준;윤광식
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.3
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    • pp.146-156
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    • 2002
  • The objective of this study was to develop a modified CREAMS model for paddy field conditions. The model simulates daily balance of water and nutrient from irrigated paddies using meteorological, irrigation, and agricultural management data. The model simulates daily evapotranspiration of paddy using Penman equation and determines daily flooding depth changes. Total nitrogen and phosphorus concentrations within flooding water, surface runoff, and leaching water from a paddy field also can be simulated. Parameters of the model were calibrated using observed data of the Agricultural Experiment Station of the Seoul National University in Suwon Korea. The model was applied for the irrigation period of paddy field in Gicheon area when 1,234 mm annual rainfall was occurred. The simulated losses of the total nitrogen and total phosphorous were 11.27 kg/ha and 0.98 kg/ha, respectively. There was a good agreement between observed and simulated data. It was found that CREAMS-PADDY model was capable of predicting runoff and nutrient losses from irrigated paddy fields.

Probabilistic Broadcasting Based on Selfishness and Additional Coverage in MANETs

  • Kim, Jae-Soo;Kim, Jeong-Hong
    • Journal of information and communication convergence engineering
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    • v.10 no.4
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    • pp.329-336
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    • 2012
  • For designing broadcast protocols in mobile ad hoc networks (MANETs), one of the important goals is to reduce the rebroadcast packets redundancy while reaching all the nodes in network. In this paper, we propose a probabilistic broadcasting mechanism based on selfishness and additional coverage in MANETs. Our approach dynamically adjusts the rebroadcast probability according to the extra covered area and number of neighbor nodes. By these two factors, mobile hosts can be classified into three groups: normal, low selfishness, and high selfishness groups. The nodes in the normal group forward packets for other nodes with high probability, whereas the nodes in the low selfishness group rebroadcast packets with low probability and the nodes in the high selfishness group do not rebroadcast packets. We compared our approach with simple flooding and the fixed probabilistic approach. The simulation results show that the proposed schemes can significantly reduce the number of retransmissions by up to 40% compared simple flooding and fixed probabilistic scheme without significant reduction in the network reachability and end-to-end packet delay.