• Title/Summary/Keyword: Urban flooding

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A Study on Flood Area Typology Using the Inundation Trace Map - A Case Study of Busan Metropolitan City - (침수흔적도를 활용한 침수지역 유형화에 관한 연구 -부산광역시를 사례로-)

  • Yoo, Chang;Hong, Soon Heon;Choi, Hyun;Nam, Kwang Woo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.5
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    • pp.393-400
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    • 2013
  • Recently, expected casuality or property damage, such as flood damage, environmental destruction, etc, is increased because of the local heavy rain or flood by climatic changes. Especially, there are lots of property damages caused by increase of flood frequency and expansion of flood area because impervious rate is increased by urban sprawling development. Therefore, this research intends to analyze reasons of flood damage by each form and suggest protective measures through the typology of flood area for Haeundae-gu, Suyoung-gu, Saha-gu in Busan Metropolitan City with Busan's inundation trace map which has made from 2009. To achieve them, flood area was divided into water flooding type, river flooding type and seawater flooding type. And, protective measures focusing on previous prevention gave the relationship by dividing into managing system aspect, infrastructure building aspect and system aspect, so it approached flooding problems more objectively and scientifically. And, this research intends to suggest vitalizing measures for the utilization of inundation trace map in the future.

Enhancing the radar-based mean areal precipitation forecasts to improve urban flood predictions and uncertainty quantification

  • Nguyen, Duc Hai;Kwon, Hyun-Han;Yoon, Seong-Sim;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.123-123
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    • 2020
  • The present study is aimed to correcting radar-based mean areal precipitation forecasts to improve urban flood predictions and uncertainty analysis of water levels contributed at each stage in the process. For this reason, a long short-term memory (LSTM) network is used to reproduce three-hour mean areal precipitation (MAP) forecasts from the quantitative precipitation forecasts (QPFs) of the McGill Algorithm for Precipitation nowcasting by Lagrangian Extrapolation (MAPLE). The Gangnam urban catchment located in Seoul, South Korea, was selected as a case study for the purpose. A database was established based on 24 heavy rainfall events, 22 grid points from the MAPLE system and the observed MAP values estimated from five ground rain gauges of KMA Automatic Weather System. The corrected MAP forecasts were input into the developed coupled 1D/2D model to predict water levels and relevant inundation areas. The results indicate the viability of the proposed framework for generating three-hour MAP forecasts and urban flooding predictions. For the analysis uncertainty contributions of the source related to the process, the Bayesian Markov Chain Monte Carlo (MCMC) using delayed rejection and adaptive metropolis algorithm is applied. For this purpose, the uncertainty contributions of the stages such as QPE input, QPF MAP source LSTM-corrected source, and MAP input and the coupled model is discussed.

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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.

Analysis of Flood Reduction in Downstream Urban Areas for the Storage in Apartment Complex (하류 도심지 침수저감 분석을 통한 공동주택 단지의 우수저류조 계획)

  • Jae-Do Choi;Hyoung-Chul Lim
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.698-709
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    • 2023
  • Purpose: In this paper, we would like to analyze the growth rate of existing urban immersion in the downstream during large-scale urban development and the degree of reduction in existing urban immersion in the downstream when small excellent storage facilities are planned in apartment complexes. Method: A large-scale sewage model was built using the SWMM model of the U.S. Environmental Protection Agency, and the impact of flooding in existing downtown areas downstream was analyzed through simulation. The built model included the development zone, the existing downtown area downstream, and the entire river basin that discharges rainwater. Result: As a result of calculating and simulating the minimum excellent reservoir capacity for each apartment block in the study target area, it was found that the immersion of 4,893㎥ based on one hour, 25,815㎥ based on two hours, and 55,528㎥ based on three hours in the downstream urban area. Conclusion: As in this study, large-scale flooding simulation considering the existing downtown area in the downstream shows a significant increase in flooding in the downstream, and if excellent reservoir capacity is planned for each apartment block before development and the construction of excellent reservoirs is recommended.

Operational Improvement of Small Urban Storm Water Pumping Station (2) - Comparative Study to Reduce the Flooding Problems using Flood Simulation Model (도시 소유역 배수펌프장 운영개선 방안 연구 (2) - 침수범람모의에 의한 침수방지 방안 비교 연구)

  • Gil, Kyung-Ik;Han, Jong-Ok;Kim, Goo-Hyun
    • Journal of Korean Society on Water Environment
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    • v.22 no.1
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    • pp.110-115
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    • 2006
  • Flooding situation of Sutak basin was simulated and simulation seemed to be consistent with the real flooding situation in terms of high water levels and timings of flooding. The flood simulation model was used to evaluate alternatives to mitigate flooding problems in Sutak basin. From the evaluation of flood mitigation plans, it was found that combined operation of Sutak and Inchang pumping stations through partial diversion of inflow of Sutak pumping station to Inchang pumping station was the most effective one among the suggested mitigation plans. About 500 meter diversion channel will be needed to send 30% of Sutak pumping station inflow to Inchang pumping station. This will reduce overload of Sutak pumping station and the storage capacity of Inchang pumping station will be more efficiently utilized.

Strength Properties of Cementless Permeable Block Based on Blast-Furnace Slag with Alkali Stimulant Additional Ratio (알칼리 자극제 첨가율에 따른 고로슬래그 기반 무시멘트 투수블록의 강도 특성)

  • Ji, Bong-Su;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.168-169
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    • 2019
  • Recently, the flooding of rivers caused by rainy season and heavy rains in Korea causes economic and environmental problems such as flood damage and urban flooding. Therefore, in order to solve these problems, local governments use landscaping methods and drainage facilities to prevent them, but they are not perfect solutions. Domestic awareness also lacks awareness to worry about flooding only during rainy seasons and heavy rains, and to worry about or prevent flooding in the region. In order to solve this problem, we recognize the importance of permeable blocks nationwide and replace or install permeable paving materials on most sidewalks. However, since existing permeable blocks used cement as the main material, calcium carbonate is produced when reacted with water. Efflorescence occurs, and the resulting calcium carbonate blocks the pores of the permeation block, causing a decrease in permeability.

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Comparison of inundation patterns of urban inundation model and flood tracking model based on inundation traces (침수 흔적도 기반으로 도시침수 모형과 홍수추적모형의 침수양상 비교)

  • Choi, Jonghwa;Jeon, Jaehyun;Kim, Taehyung;Kim, Byungsik
    • Journal of Korea Water Resources Association
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    • v.54 no.2
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    • pp.71-80
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    • 2021
  • In recent years, the possibility of flooding due to the increase in the incidence of high-frequency rainfall due to abnormal rainfall and the increase in concentrated torrential rain is increasing. Also, the amount of rainwater runoff is increasing due to the increase of the impermeable layer in the city due to the concentration of population due to urbanization and concentration of development. Due to the characteristics of the developed city, it is located in the vicinity of rivers and in the lowlands. For the analysis of inundation in water, using XP-SWMM, which can analyze stormwater pipelines and surface flows, and FLO-2D models that can track flood-sluice curves and rainfall-spill curves, based on hydraulic and hydrological analysis. Inundation analysis was conducted and comparative review was conducted. The patterns of flooding of the two models were compared, and a model suitable for domestic flooding was selected.

Flooding Risk Assessment Using Flooding Characteristic Values (침수특성치를 이용한 침수위험성 평가)

  • Ahn, Jeonghwan;Kim, Kunwoo;Cho, Woncheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.957-964
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    • 2013
  • This research is on the methodology of flood risk assessment using flooding characteristic values. Necessity of design magnitude for flood control considering floods was judged by plotting peak flow with respect to frequency and duration, and flooding magnitude was defined with 6 flooding characteristic values which were proposed to be significant factors when assessing flooding magnitude. Precipitation data used in the assessment modeling were applied by combining all the possible precipitation events. After overlapping the simulated results with precipitation matrix by flooding characteristic values, contour map was drawn, and Flooding characteristic contour graph for possible rainfall events were suggested in respect of all possible precipitation. Flooding characteristic contour graph for possible rainfall events was confirmed that reducing of damage magnitude of each flood characteristic value was figured out easily. The flood risk assessment methods suggested in this study would be a good reference for urban drainage system design, which only focuses on pipe conduit.

Application of adaptive mesh refinement technique on digital surface model-based urban flood simulation

  • Dasallas, Lea;An, Hyunuk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.122-122
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    • 2020
  • Urban flood simulation plays a vital role in national flood early warning, prevention and mitigation. In recent studies on 2-dimensional flood modeling, the integrated run-off inundation model is gaining grounds due to its ability to perform in greater computational efficiency. The adaptive quadtree shallow water numerical technique used in this model implements the adaptive mesh refinement (AMR) in this simulation, a procedure in which the grid resolution is refined automatically following the flood flow. The method discounts the necessity to create a whole domain mesh over a complex catchment area, which is one of the most time-consuming steps in flood simulation. This research applies the dynamic grid refinement method in simulating the recent extreme flood events in Metro Manila, Philippines. The rainfall events utilized were during Typhoon Ketsana 2009, and Southwest monsoon surges in 2012 and 2013. In order to much more visualize the urban flooding that incorporates the flow within buildings and high-elevation areas, Digital Surface Model (DSM) resolution of 5m was used in representing the ground elevation. Results were calibrated through the flood point validation data and compared to the present flood hazard maps used for policy making by the national government agency. The accuracy and efficiency of the method provides a strong front in making it commendable to use for early warning and flood inundation analysis for future similar flood events.

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Scaled Down Experiment of Retention Basin with a Rotatable Bucket Using 3D Printer (3D 프린터를 이용한 회전 버킷이 부착된 저류조의 모형 실험)

  • Park, Seong-Jik;Lee, Chang-Gu;Lee, Jemyung;Choi, Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.2
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    • pp.49-55
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    • 2017
  • Recently climate change and urbananization have been increased surface runoff, resulting in flooding. Retention basins have been constructed to control urban flooding by reducing peak flow rate. Recently, the retention basin plays a role in controlling combined sewer overflows (CSOs) as well as urban flooding. In this study, the retention basin with a rotatable bucket was suggested and scale down experiments was performed for the optimum design of the retention basin. Scaled down model was produced using a 3D printer after it was designed as law of similarity. Two times for operating a rotary bucket is required to sweep out the sediments deposited on the bottom of the basin. Optimized dimensions for the retention basin were width of 5 m, height of 5 m, bucket radius of 0.5 m, and bottom slope of 5.0 %. It can be concluded that the results obtained from this study can be used to design the retention basin with a rotatable bucket which does not require energy to operate.