• Title/Summary/Keyword: Local flooding

Search Result 111, Processing Time 0.027 seconds

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
    • /
    • v.59 no.2
    • /
    • pp.81-90
    • /
    • 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.

Flood Damage Assessment According to the Scenarios Coupled with GIS Data (GIS 자료와 연계한 시나리오별 홍수피해액 분석)

  • Lee, Geun-Sang;Park, Jin-Hyeg
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.19 no.4
    • /
    • pp.71-80
    • /
    • 2011
  • A simple and an improved methods for the assessment of flood damage were used in previous studies, and the Multi-Dimensional Flood Damage Assessment (MD-FDA) has been applied since 2004 in Korea. This study evaluated flood damage of dam downstream using considering MD-FDA method based on GIS data. Firstly, flood water level with FLDWAV (Flood Wave routing) model was input into cross section layer based on enforcement drainage algorithm, water depth grid data were created through spatial calculation with DEM data. The value of asset of building and agricultural land according to local government was evaluated using building layer from digital map and agricultural land map from landcover map. Also, itemized flood damage was calculated by unit price to building shape, evaluated value of housewares to urban type, unit cost to crop, tangible and inventory asset of company connected with building, agricultural land, flooding depth layer. Flood damage in rainfall frequency of 200 year showed 1.19, 1.30 and 1.96 times to flood damage in rainfall frequency of 100 year, 50 year and 10 year respectively by flood damage analysis.

Efficient Signal Filling Method Using Watershed Algorithm for MRC-based Image Compression (MRC 기반의 영상 부호화를 위한 분수령 알고리즘을 이용한 효과적인 신호 채움 기법)

  • Park, Sang-Hyo;Lee, Si-Woong
    • The Journal of the Korea Contents Association
    • /
    • v.15 no.2
    • /
    • pp.21-30
    • /
    • 2015
  • Image coding based on mixed raster content model generates don't care regions (DCR) in foreground and background layers, and its overall coding performance is greatly affected by region filling methods for DCRs. Most conventional methods for DCR filling fail in utilizing the local signal properties in hole regions and thus the high frequency components in non-DCR regions are reflected into DCR after signal filling. In addition, further high frequency components are induced to the filled signal because of signal discontinuities in the boundary of DCR. To solve this problem, a new DCR filling algorithm using the priority-based adaptive region growing is proposed in this paper. The proposed method uses the watershed algorithm and the flooding priority of each pixel for region filling is determined from the degree of smoothness in the neighborhood area. By growing the filled region into DCR based on the computed priority, the expansion of high-textured area can be minimized which can improve the overall coding performance. Experimental results show that the proposed method outperforms conventional algorithms.

Accuracy evaluation of threshold rainfall impacting pedestrian using ROC (ROC를 이용한 보행에 영향을 미치는 한계강우량의 정확도 평가)

  • Choo, Kyungsu;Kang, Dongho;Kim, Byungsik
    • Journal of Korea Water Resources Association
    • /
    • v.53 no.12
    • /
    • pp.1173-1181
    • /
    • 2020
  • Recently, as local heavy rains occur frequently in a short period of time, economic and social impacts are increasing beyond the simple primary damage. In advanced meteorologically advanced countries, realistic and reliable impact forecasts are conducted by analyzing socio-economic impacts, not information transmission as simple weather forecasts. In this paper, the degree of flooding was derived using the Spatial Runoff Assessment Tool (S-RAT) and FLO-2D models to calculate the threshold rainfall that can affect human walking, and the threshold rainfall of the concept of Grid to Grid (G2G) was calculated. In addition, although it was used a lot in the medical field in the past, a quantitative accuracy analysis was performed through the ROC analysis technique, which is widely used in natural phenomena such as drought or flood and machine learning. As a result of the analysis, the results of the time period similar to that of the actual and simulated immersion were obtained, and as a result of the ROC (Receiver Operating Characteristic) curve, the adequacy of the fair stage was secured with more than 0.7.

Development of distributed inundation routing method using SIMOD method (SIMOD 기법을 이용한 분포형 침수 추적 기법 개발)

  • Lee, Suk Ho;Lee, Dong Seop;Kim, Jin Man;Kim, Byung Sik
    • Journal of Korea Water Resources Association
    • /
    • v.49 no.7
    • /
    • pp.579-588
    • /
    • 2016
  • Changes in precipitation due to climate change is made to induce the local and intensive rainfall, it is increasing damage caused by inland inundation. Therefore, it requires a technique for predicting damage caused by flooding. In this study, in order to determine whether this flood inundated by any route when the levee was destroyed, Which can simulate the path of the flood inundation model was developed for the SIMOD (Simplified Inundation MODel). Multi Direction Method (MDM) for differential distributing the adjacent cells by using the slope and Flat-Water Assumption (FWA)-If more than one level higher in the cell adjacent to the cell level is the lowest altitude that increases the water level is equal to the adjacent cells- were applied For the evaluation of the model by setting the flooding scenarios were estimated hourly range from the target area. SIMOD model can significantly reduce simulation time because they use a simple input data of topography (DEM) and inflow flood. Since it is possible to predict results within minutes, if you can only identify inflow flood through the runoff model or levee collapse model. Therefore, it could be used to establish an evacuation plan due to flooding, such as EAP (Emergency Action Plan).

A Study on the Stormwater Drainage Method of Overflow Type for the Prevention of Urban Flood due to Abnormal Precipitation (이상강우 발생시 도시침수 방지를 위한 월류형 우수배수방법 연구)

  • Seo, Se Deok;Park, Hyung Keun;Kim, Tae Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.39 no.5
    • /
    • pp.569-577
    • /
    • 2019
  • Urban flooding has been a frequent phenomenon in recent years caused by the increase in maximum stormwater runoff arising from abnormal rainfall due to global warming, urban development, and development of lowlands according to population inflows. In order to respond positively against abnormal precipition in the city, it is necessary to check the GWI (Green Water Infra) effect and effectively utilize the existing stormwater detention tanks and treat stormwater to prevent local flooding. In this study, Overflow Type stormwater drainage methods are evaluated as a method of preventing urban flooding in abnormal precipitation using the Dynamic Wave Analysis SWMM (Storm Water Management Model) provided by the United States Environmental Protection Agency. Comparing and analyzing the Upward Watergate Type and Overflow Type, it was analyzed that the Overflow Type reduces the maximum flood discharge by 61 % and the total flood volume by 56 % in the rainfall of Typhoon Kong-rey. The application of the Overflow Type and the natural-pneumatic drainage method to the rainfall of Typhoon Soulik resulted in a 20 % reduction in maximum flood runoff and a 67 % reduction in total flood quantity. Therefore, as a solution to the abnormal rain fall, it is possible to improve the existing stormwater detection tank and install additional facilities. It is expected to be economically possible to strom drainage under limited conditions.

Development of Flood Rapid Defense System(FRDS) suitable for Southeast Asian Disaster (동남아시아 재난에 적합한 도심형 홍수임시차수시스템 개발)

  • Jung, In-Su;Oh, Eun-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.11
    • /
    • pp.8-17
    • /
    • 2018
  • A large urban region in Bangkok, Thailand is often inundated due to shallow water floods along the paved roads that have poor drainage facilities, and that can cause urban flooding. Existing methods, including using sand bags are not effective to prevent flooding in urban areas where the amount of sand is not sufficient. Thus, it is necessary to install artificial flood defense structures. However flooding and overflow defense equipment, which was developed in some advanced nations in Europe and in the USA, is highly expensive and complex construction methods are needed, therefore they are not suitable to be used in Southeast Asia. Thus, it is necessary to develop a flood rapid defense system(FRDS), which is inexpensive and simple to build, but is also highly functional. Thus, this study developed an FRDS that can be applied to Southeast Asia through the careful study of FRDS overviews, an analysis on the development trends in Korea and overseas, and the proposal of development needs and directions of the region. For the system developed, Korean Standards(KS) performance evaluations on leakage ratio deformation tests and impact resistance tests were conducted at the Outdoor Demonstration Test Center(Seosan) in the Korea Conformity Laboratories(KCL) and the system satisfied the standards of KS F 2639(leakage and deformation test) and KS F 2236(impact resistance test). The present study results can not only be applied to urban floods in Southeast Asian nations to cope with flood-related disasters, but also be utilized in flood prone regions and for major facilities in Korea. They can also induce scientific and pro-active responses from major local governments and facility management organizations in relation to urban floods.

The Effect of Road Networks on Urban Resilience in Flooding (도시침수 시 도로네트워크가 도시회복도에 미치는 영향 분석)

  • Hyung Jun Park;Dong Hyun Kim;Hyun Jung Lee;Seung Oh Lee
    • Journal of Korean Society of Disaster and Security
    • /
    • v.16 no.2
    • /
    • pp.85-98
    • /
    • 2023
  • Flood is one of the most frequent natural disasters worldwide. In Korea, the probability of urban flooding is greatly increasing due to complex factors such as global warming, an increase in impervious areas, and limitations in expanding water supply facilities in existing urban areas. However, large-scale civil engineering works to prevent urban inundation are socially and economically difficult to obtain national consent. Recently the importance of resilience, which is the ability to return to the original state after a disaster through rapid recovery while preparing for natural disasters to a level that the local community can afford socially and economically, is increasing. Accordingly, various studies on urban resilience have been conducted, but the resilience measurement method related to the lifeline that provides essential services of the city is insufficient. However, among lifelines, road networks are important facilities for the transportation of recovery resources and rapid recovery in the event of a natural disaster, so road networks are a major factor that must be considered when measuring the degree of recovery of a city in the field of natural disasters. Therefore, this study proposes a recovery evaluation method considering the characteristics of resilience and road networks in the urban flooding field and analyzes the effect of road networks on urban resilience.

An Improved Route Recovery using Bidirectional Searching Method for Ad hoc Networks (Ad hoc 네트워크에서의 양방향 경로탐색을 이용한 경로복구 개선 방안)

  • Han, Ho-Yeon;Nam, Doo-Hee;Kim, Seung-Cheon
    • Journal of KIISE:Information Networking
    • /
    • v.37 no.1
    • /
    • pp.35-41
    • /
    • 2010
  • Since the ad-hoc network allow nodes to communicate each other without infrastructure system and predefined configuration, it comes into the spotlight that is suitable to ubiquitous society. In ad-hoc network, route recovery mechanism is considered important. Normally route recovery is needed to solve the link failure problem because there is no route maintaining system like a router in ad-hoc networks. In this paper we propose BS-AODV(Bidirectional Searching-AODV) route recovery method. The proposed method is a local repair method that can be applied in all of the network area. Unlike a limited local repair method in AODV. the proposed method adopts the bidirectional searching method where the upstream/downstream nodes can send the route maintenance messages. Restricting the flooding of route request messages, the proposed scheme attempts to minimize the costs of local repair, the performance of the proposed scheme is evaluated through the simulations. In two scenarios which variate the node numbers and node speed, the comparison among the proposed scheme, AODV and AOMDV is shown in terms of the control traffic and data delivery ratio.

Techniques of flood damage investigation and flood losses data management (홍수재해조사 및 재해자료관리 기법)

  • 김양수
    • The Journal of Engineering Geology
    • /
    • v.10 no.2
    • /
    • pp.36-51
    • /
    • 2000
  • Almost every year, Korean suffered from the repetitive natural disasters such as typhoons and floods. During last 10 years, Korea experienced annual average of $50 million property damages caused by inundation. To estabilish the flood disaster counter plan, knowledge for flood damage causes based on the field investigations of inundated area is required. The field investigations is focused on technique to document and analyze the meteorological conditions leading to torrential rains, the causes and patterns of flooding, the performance of flood control structures in affected areas, the extent damages and the effectiveness of local emergency response and recovery actions. We did comparative analysis of field investigation techniques. As a major goal of flood hazard map design, one of non structural disaster countermeasures, it was expected to reduce flood damage losses by requiring local governments to implement land-use regulation that would result in safe building practices in flood hazard areas. This requires local governments to develop flood hazard maps to assess how to manage particularly vulnerable floodplain areas. In this study we suggested a design manual and the management system of flood hazard map.

  • PDF