• Title/Summary/Keyword: Flood Vulnerability

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The Assessment of Future Flood Vulnerability for Seoul Region (서울 지역의 미래 홍수취약도 평가)

  • Sung, Jang Hyun;Baek, Hee-Jeong;Kang, Hyun-Suk;Kim, Young-Oh
    • Journal of Wetlands Research
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    • v.14 no.3
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    • pp.341-352
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    • 2012
  • The purpose of this study is to statistically project future probable rainfall and to quantitatively assess a future flood vulnerability using flood vulnerability model. To project probable rainfall under non-stationarity conditions, the parameters of General Extreme Value (GEV) distribution were estimated using the 1 yr data added to the initial 30 yr base series. We can also fit a linear regression model between time and location parameters after comparing the linear relationships between time and location, scale, and shape parameters, the probable rainfall in 2030 yr was calculated using the location parameters obtained from linear regression equation. The flood vulnerability in 2030 yr was assessed inputted the probable rainfall into flood vulnerability assessment model suggested by Jang and Kim (2009). As the result of analysis, when a 100 yr rainfall frequency occurs in 2030 yr, it was projected that vulnerability will be increased by spatial average 5 % relative to present.

Vulnerability Analysis in the Nakdong River Basin for the Utilization of Flood Risk Mapping (홍수위험지도 활용을 위한 낙동강 유역에서의 홍수취약도 분석)

  • Kim, Tae-Hyung;Han, Kun-Yeun;Cho, Wan-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.3
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    • pp.203-222
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    • 2011
  • The characteristics of flood damages have been increasingly strengthened and take the form of unpredictable and unusual weather phenomena caused by climate change and climate anomalies. To prevent inundation damage caused by breach of hydraulic structure such as dam or levee, and trouble of drainage of inner basin, the prediction necessity of flood inundation area, flood risk analysis, and drawing flood risk maps have been on the rise, and the national flood risk maps have been produced. In this study, the quantitative flood vulnerability analysis was performed, which represents population living within flood-affected areas, types of economic activities, facilities affected by flood, in order to extend flood risk mapping from simple hazard concept into risk based idea. By applying it to Nakdong River basin, the flood vulnerability indices were estimated to draw flood risk maps subdivided into administrative districts. The result of this study can be applied to establish the disaster prevention measures and priority decision of disaster prevention project.

Flood vulnerability analysis in Seoul, Korea (한국 도심지에서의 홍수취약성 분석)

  • Hwang, Nanhee;Park, Heeseong;Chung, Gunhui
    • Journal of Korea Water Resources Association
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    • v.52 no.10
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    • pp.729-742
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    • 2019
  • Natural disasters such as floods has been increased in many parts of the world, also Korea is no exception. The biggest part of natural damage in South Korea was caused by the flooding during the rainy season in every summer. The existing flood vulnerability analysis cannot explain the reality because of the repeated changes in topography. Therefore, it is necessary to calculate a new flood vulnerability index in accordance with the changed terrain and socio-economic environment. The priority of the investment for the flood prevention and mitigation has to be determined using the new flood vulnerability index. Total 25 urban districts in Seoul were selected as the study area. Flood vulnerability factors were developed using Pressure-State-Response (PSR) structures. The Pressure Index (PI) includes nine factors such as population density and number of vehicles, and so on. Four factors such as damage of public facilities, etc. for the Status Index (SI) were selected. Finally, seven factors for Response Index (RI) were selected such as the number of evacuation facilities and financial independence, etc. The weights of factors were calculated using AHP method and Fuzzy AHP to implement the uncertainties in the decision making process. As a result, PI and RI were changed, but the ranks in PI and RI were not be changed significantly. However, SI were changed significanlty in terms of the weight method. Flood vulnerability index using Fuzzy AHP shows less vulnerability index in Southern part of Han river. This would be the reason that cost of flood mitigation, number of government workers and Financial self-reliance are high.

Assessment of Flood Vulnerability for Small Reservoir according to Climate Change Scenario - Reservoir in Gyeonggi-do - (기후변화 시나리오에 따른 소규모 저수지의 홍수 취약성 평가 - 경기도 내 저수지를 중심으로 -)

  • Heo, Joon;Bong, Tae-Ho;Kim, Seong-Pil;Jun, Sang-Min
    • Journal of The Korean Society of Agricultural Engineers
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    • v.64 no.5
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    • pp.53-65
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    • 2022
  • Most of the reservoirs managed by the city and county are small and it is difficult to respond to climate change because the drainage area is small and the inflow increases rapidly when a heavy rain occurs. In this study, the current status of reservoirs managed by city and county in Gyeonggi-do was reviewed and flood vulnerability due to climate change was analyzed. In order to analyze the impact of climate change, CMIP6-based future climate scenario provided by IPCC was used, and future rainfall data was established through downscaling of climate scenario (SSP8-8.5). The flood vulnerability of reservoirs due to climate change was evaluated using the concept provided by the IPCC. The future annual precipitation at six weather stations appeared a gradual increase and the fluctuation range of the annual precipitation was also found to increase. As a result of calculating the flood vulnerability index, it was analyzed that the flood vulnerability was the largest in the 2055s period and the lowest in the 2025s period. In the past period (2000s), the number of D and E grade reservoirs was 58, but it was found to increase to 107 in the 2055s period. In 2085s, there were 17 E grade reservoirs, which was more than in the past. Therefore, it is necessary to take measures against the increasing risk of flooding in the future.

Mapping of Inundation Vulnerability Using Geomorphic Characteristics of Flood-damaged Farmlands - A Case Study of Jinju City - (침수피해 정보를 이용한 농경지의 지형학적 침수취약지도 작성 - 진주시를 사례로 -)

  • Kim, Soo-Jin;Suh, Kyo;Kim, Sang-Min;Lee, Kyung-Do;Jang, Min-Won
    • Journal of Korean Society of Rural Planning
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    • v.19 no.3
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    • pp.51-59
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    • 2013
  • The objective of this study was to make a map of farmland vulnerability to flood inundation based on morphologic characteristics from the flood-damaged areas. Vulnerability mapping based on the records of flood damages has been conducted in four successive steps; data preparation and preprocessing, identification of morphologic criteria, calculation of inundation vulnerability index using a fuzzy membership function, and evaluation of inundation vulnerability. At the first step, three primary digital data at 30-m resolution were produced as follows: digital elevation model, hill slopes map, and distance from water body map. Secondly zonal statistics were conducted from such three raster data to identify geomorphic features in common. Thirdly inundation vulnerability index was defined as the value of 0 to 1 by applying a fuzzy linear membership function to the accumulation of raster data reclassified as 1 for cells satisfying each geomorphic condition. Lastly inundation vulnerability was suggested to be divided into five stages by 0.25 interval i.e. extremely vulnerable, highly vulnerable, normally vulnerable, less vulnerable, and resilient. For a case study of the Jinju, farmlands of $138.6km^2$, about 18% of the whole area of Jinju, were classified as vulnerable to inundation, and about $6.6km^2$ of farmlands with elevation of below 19 m at sea water level, slope of below 3.5 degrees, and within 115 m distance from water body were exposed to extremely vulnerable to inundation. Comparatively Geumsan-myeon and Sabong-myeon were revealed as the most vulnerable to farmland inundation in the Jinju.

Development and the Application of Flood Disaster Risk Reduction Index (홍수피해저감지수(FDRRI) 개발 및 시범적용)

  • Moon, Seung-Rok;Yang, Seung-Man;Choi, Seon-Hwa
    • Journal of the Korean Society of Safety
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    • v.29 no.1
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    • pp.64-69
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    • 2014
  • Community-based disaster preparedness approaches are increasingly important elements of vulnerability reduction and disaster strategies. They are associated with a policy trend that values the knowledge and capacities of local people. In this research, we describe the community diagnosis method and develop Flood Disaster Risk Reduction Index(FDRRI) for assessment of flood vulnerability. FDRRI is composed of four indicators such as Flood Exposure Indicator(FEI), Sensitivity Indicator(SI), Risk Reduction Indicator(RRI), and Community Preparedness Indicator(CPI). We anticipate to present the guideline for selection national preparedness projects and uplift community's preparedness capacity.

Development of Integrated Water Resources Evaluation Index (통합수자원평가지수의 개발)

  • Lee, Dong-Ryul;Choi, Si Jung;Moon, Jang Won
    • Journal of Korea Water Resources Association
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    • v.46 no.10
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    • pp.1017-1028
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    • 2013
  • The purpose of this research is to develop an Integrated Water Resources Evaluation Index (IWREI) which can used to assess the performance of water resources projects in a regional perspective focusing on three major sectors including water use, flood, and river environment in water resources policies. The IWREI is estimated by integrating the Water Use Vulnerability Index (WUVI), the Flood Vulnerability Index (FVI), and the River Environment Vulnerability Index (REVI) which represent the vulnerability in each sector. These indices consist of total 26 indicators selected from the pressure indicators representing the causes of damages in water use, flood, and river environment, the state indicators and the response indicators. The estimated index describes the vulnerability and effectiveness of policies with five levels: Low, Medium Low, Medium, Medium High, and High. The results of evaluating total 115 hydrological units in Korea using the WUVI, FVI, REVI, and IWREI indicate that the project effectiveness in water resources policies is clearly verified by the improved index results compared to the past (early 1990s). Regional vulnerability and evaluation indices developed in this research could be used to establish goals of water resources policy and to select priority regions for project implementation.

A Study on Urban Flood Vulnerability Assessment Considering Social Impact (사회적 평가 지표를 반영한 도시 홍수취약성 평가)

  • Lee, Gyu Min;Choi, Jin Won;Jun, Kyung Soo
    • Land and Housing Review
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    • v.11 no.1
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    • pp.109-116
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    • 2020
  • This study aims to establish an approach to assess urban flood vulnerability by identifying social characteristics such as the road transportation and the vulnerable groups. Assessment procedures comprise three steps as: (1) composing the assessment criteria to reflect the urban characteristics; (2) calculating the weight; and (3) evaluating the vulnerability. The criteria were adopted by Delphi survey technique. Four criteria as land cover, residents, vulnerable areas, and disaster response were adopted in the current study. To determine the weight set of criteria, subjective and objective methods were combined. The weight set was determined using the combined method which reflects the Delphi method and Entropy analysis. In the process of data-based construction, GIS tools wwere used to extract administrative unit materials such as land cover, road status, and slope. Data on population and other social criteria were collected through the National Statistical Office and the Seoul Metropolitan statistical data. TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) technique, which uses materials from cell units in order to rank the closest distance to the best case and the farthest distance from the worst case by calculating the distances to the area of assessment, was applied to assess. The study area was the Dorimcheon basin, a flood special treatment area of Seoul city. The results from the current study indicates that the established urban flood vulnerability assessment approach is able to predict the inherent vulnerable factors in urban regions and to propose the area of priority control.

A Preliminary Study for Vulnerability Assessment to Natural Hazards in Gyeongsangnam-do (경남 시군별 자연재해 취약성 평가 및 유형 분류)

  • Kim, Sung Jae;Kim, Yong Wan;Choi, Young Wan;Kim, Sung Min;Jang, Min Won
    • KCID journal
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    • v.19 no.1
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    • pp.97-105
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    • 2012
  • This study aimed to evaluate the vulnerability to different natural hazards such as flood, drought, and abnormal climate, and to classify the vulnerability patterns in Gyeongsangnam-do. The damage records and annual budgets during 2000 to 2009 were collected and were ranked for all twelve si-guns. Sancheong-gun and Hamyang-gun resulted in the most vulnerable to flood and drought damages, and Hadong-gun and Yangsan-si were most damaged from abnormal climate such as heavy snow and heavy wind. In addition, three clusters were classified by using Ward's method, and were interpreted. The results showed that the western areas of Gyeongsangnam-do might be more vulnerable to flood damage while drought might threaten the eastern si-guns.

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Impact spectrum of flood hazard on seismic vulnerability of bridges

  • Yilmaz, Taner;Banerjee, Swagata
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.515-529
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    • 2018
  • Multiple hazards (multihazard) conditions may cause significant risk to structures that are originally designed for individual hazard scenarios. Such a multihazard condition arises when an earthquake strikes to a bridge pre-exposed to scour at foundations due to flood events. This study estimates the impact spectrum of flood-induced scour on seismic vulnerability of bridges. Characteristic river-crossing highway bridges are formed based on the information obtained from bridge inventories. These bridges are analyzed under earthquake-only and the abovementioned multihazard conditions, and bridge fragility curves are developed at component and system levels. Research outcome shows that bridges having pile shafts as foundation elements are protected from any additional seismic vulnerability due to the presence of scour. However, occurrence of floods can increase seismic fragility of bridges at lower damage states due to the adverse impact of scour on bridge components at superstructure level. These findings facilitate bridge design under the stated multihazard condition.