Flood Disaster in Japan

2007 ◽  
Vol 2 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Kazuya Inoue ◽  
Keyword(s):  
Social Factors ◽  
Urban Areas ◽  
Flood Control ◽  
Control Policy ◽  
Material Damage ◽  
Urban Flood ◽  
Flood Disasters ◽  
Development Accounting ◽  
New Type ◽  
Area Development

Progress against flood disasters since the end of Word War II has shown that although human casualties have sharply decreased, material damage has not, despite improvements in flood control facilities. This is partly due to the increased concentration of buildings, infrastructures, and other assets in urban areas. Both natural and social factors are listed, and the implementation of suitable flood control policies is indispensable to saving lives and mitigating disasters in the future. Urban flood disasters are focused as a new type disaster explained in detail, stressing a combination of structural and non-structural measures and wide-area development accounting for both rivers and their entire basins to distribute the load in terms of flood control policy.

UAV-LiDAR observations increase the precision of urban flood modelling in Accra by detecting critical micro-topographic features

2021 ◽  
Author(s):  
Katerina Trepekli ◽  
Thomas Friborg ◽  
Thomas Balstrøm ◽  
Bjarne Fog ◽  
Albert Allotey ◽  
...  
Keyword(s):  
High Resolution ◽  
Urban Areas ◽  
Flood Control ◽  
Substantial Effect ◽  
Control Measures ◽  
Damage Potential ◽  
Urban Flood ◽  
Proactive Management ◽  
Precise Identification ◽  
Flood Prone Areas

<p>Rapidly expanding cities are exposed to higher damage potential from floods, necessitating effective proactive management using technological developments in remote sensing observations and hydrological modelling.  In this study we tested whether high resolution topographic data derived by Light and Detection Ranging (LiDAR) and Unmanned Aerial Vehicle (UAV) systems can facilitate rapid and precise identification of high-risk urban areas, at the local scale. Three flood prone areas located within the Greater Accra Metropolitan Area in Ghana were surveyed by a UAV-LiDAR system. In order to simulate a realistic flow of precipitation runoff on terrains, Digital Terrain Models (DTM) including buildings and urban features that may have a substantial effect on water flow pathways (DTMb) were generated from the UAV-LiDAR datasets. The resulting DTMbs, which had a spatial resolution of 0.3 m supplemented a satellite-based DTM of 10 m resolution covering the full catchment area of Accra, and applied to a hydrologic screening model (Arc-Malstrøm) to compare the flood simulations. The precision of the location, extent and capacity of landscape sinks were substantially improved when the DTMbs were utilized for mapping the flood propagation. The semi-low resolution DTM projected unrealistically shallower sinks, with larger extents but smaller capacities that consequently led to an overestimation of the runoff volume by 15% for a sloping site, and up to 65 % for 1st order sinks in flat terrains. The observed differences were attributed to the potential of high resolution DTMbs to detect urban manmade features like archways, boundary walls and bridges which were found to be critical in predictions of runoff’s courses, but could not be captured by the coarser DTM. Discrepancies in the derived water volumes using the satellite-based DTM vs. the UAV-LiDAR DTMbs were also traced to dynamic alterations in the geometry of streams and rivers, due to construction activities occurring in the interval between the aerial campaign and the date of acquisition of the commercially available DTM. Precise identification of urban flood prone areas can be enhanced using UAV-LiDAR systems, facilitating the design of comprehensive early flood-control measures, especially in urban settlements exposed to the adverse effects of perennial flooding. This research is funded by a grant awarded by the Danish Ministry of Foreign Affairs (Danida).</p>

scholarly journals Urban Flood Prevention and Early Warning System in Jinan City

2018 ◽  
Vol 38 ◽  
pp. 03047
Author(s):  
Shiyuan Feng ◽  
Qingguo Li
Keyword(s):  
Early Warning ◽  
Urban Areas ◽  
Flood Control ◽  
Comprehensive Evaluation ◽  
Warning System ◽  
Fuzzy Comprehensive Evaluation ◽  
Urban Flood ◽  
Evaluation Indexes ◽  
Jinan City ◽  
High Standards

The system construction of urban flood control and disaster reduction in China is facing pressure and challenge from new urban water disaster. Under the circumstances that it is difficult to build high standards of flood protection engineering measures in urban areas, it is particularly important to carry out urban flood early warning. In Jinan City, a representative inland area, based on the index system of early warning of flood in Jinan urban area, the method of fuzzy comprehensive evaluation was adopted to evaluate the level of early warning. Based on the cumulative rainfall of 3 hours, the CAflood simulation results based on cellular automaton model of urban flooding were used as evaluation indexes to realize the accuracy and integration of urban flood control early warning.

scholarly journals Collaborative Development of Green Infrastructure: Urban Flood Control Measures on Small-Scale Private Lands

2021 ◽  
Vol 16 (3) ◽  
pp. 457-468
Author(s):  
Fumiko Taura ◽  
Masaki Ohme ◽  
Yukihiro Shimatani ◽  
◽  
Keyword(s):  
Green Infrastructure ◽  
Urban Areas ◽  
Flood Control ◽  
Control Measures ◽  
Japanese Culture ◽  
Small Scale ◽  
Soil Infiltration ◽  
Private Lands ◽  
Urban Flood ◽  
Runoff Reduction

Focusing on green infrastructure (GI), which utilizes nature’s diverse resources, we developed urban flood control measures on three small-scale private tracts in Tokyo and Fukuoka in Japan, experiencing high rainfall. In addition, we implemented these measures and verified the possibility of introduction. Using a target rainfall of 100 mm/h and previous rainfall data, we set our goal of reducing runoff from each site below the capacity of a public sewage pipe. Implementation was conducted by assessing the soil infiltration rate and developing and installing rain gardens and storage layers using crushed stones. These measures satisfied the initially set goals, drastically reducing runoff at all three sites. The target installation cost was set at 100,000 yen per cubic meter of runoff reduction. The target costs were met in the two Fukuoka sites but not at the Tokyo site. The key reasons were the high costs of removing non-permeable surfaces or improving the soil of compacted surfaces, which called for a process to balance the runoff reduction and cost to determine the most effective plan for implementing GI in urban areas. The development and implementation processes were conducted in collaboration with the house owners and concerned parties; the workshops produced constructive ideas being unconstrained by conventional thinking. Visitors highly appreciated ideas related to using water because the techniques were derived from the Japanese culture of lifestyle. Thus, introducing attractive and effective GI may be possible through collaboration. Additionally, sharing experiences led to the formation of new community ties, supporting post-implementation site maintenance.

scholarly journals Assessing Urban Areas’ Vulnerability to Flood Disaster Based on Text Data: A Case Study in Zhengzhou City

2019 ◽  
Vol 11 (17) ◽  
pp. 4548 ◽  
Author(s):  
Wu ◽  
Shen ◽  
Wang
Keyword(s):  
Big Data ◽  
Vulnerability Assessment ◽  
Urban Areas ◽  
Flood Control ◽  
Flood Disaster ◽  
Assessment Model ◽  
Text Data ◽  
Disaster Vulnerability ◽  
Model Based ◽  
Flood Disasters

Confronting the frequent flood disasters triggered by torrential downpour, the vulnerability of urban rainstorm flood disasters was analyzed with one highly popular area of research in mind: big data. Web crawler technology was used to extract text information related to floods from Internet and popular social media platforms. Combining these text data with traditional statistical data, a flood disaster vulnerability assessment model based on Analytic Hierarchy Process (AHP) was established to evaluate rainstorm and flood disaster vulnerability, and the spatial distribution characteristics of vulnerability to pluvial flooding were analyzed based on Geographic Information System (GIS). The established model was applied in Zhengzhou, a city that often suffers from heavy rainstorms. The results show that the areas located near downtown Zhengzhou were more vulnerable to rainstorm and flooding than others, and most of the city could be at moderate and high vulnerability. Finally, the waterlogging spots extracted from various sources were used to evaluate the performance of the proposed model. The results show that most of waterlogging spots were located in very-high and high risk zones, while less waterlogging spots were found in districts with low vulnerability, which demonstrates the discriminative power of the established model based on big data sources. This study overcomes limited data in flood disaster vulnerability assessment methods and provides a basis for flood control and management in cities.

Study on Urban Flood Control in Yibin Reach

2013 ◽  
Vol 838-841 ◽  
pp. 1780-1784
Author(s):  
Juan Dai ◽  
Lan Mao ◽  
Ling Yun Li
Keyword(s):  
Flood Control ◽  
Analytical Study ◽  
Regional Economy ◽  
Economic Benefits ◽  
Social Benefits ◽  
Ecological Environment ◽  
Natural Conditions ◽  
Urban Flood ◽  
Social And Economic Development ◽  
Flood Disasters

This paper makes a detailed analysis on the natural conditions, flood disasters and watercourse conditions and evolution in Yibin, and conducts an analytical study on the flood control in Yibin Reach based on the needs of social and economic development in Yibin City. Based on hydrologic and hydraulic calculations as well as the layout of the project, it puts forward the recommendations for urban flood control in Yibin Reach, which is of great importance to improve the regional ecological environment and promote the development of regional economy in Yibin, and can bring considerable social benefits and economic benefits.

scholarly journals Assessing the Impact of Street-View Greenery on Fear of Neighborhood Crime in Guangzhou, China

2021 ◽  
Vol 18 (1) ◽  
pp. 311
Author(s):  
Fengrui Jing ◽  
Lin Liu ◽  
Suhong Zhou ◽  
Jiangyu Song ◽  
Linsen Wang ◽  
...  
Keyword(s):  
Social Factors ◽  
Urban Areas ◽  
Fear Of Crime ◽  
Green Space ◽  
Learning Approach ◽  
Perceived Safety ◽  
Street View ◽  
The Impact ◽  
The Relationship ◽  
Physical Incivilities

Previous literature has examined the relationship between the amount of green space and perceived safety in urban areas, but little is known about the effect of street-view neighborhood greenery on perceived neighborhood safety. Using a deep learning approach, we derived greenery from a massive set of street view images in central Guangzhou. We further tested the relationships and mechanisms between street-view greenery and fear of crime in the neighborhood. Results demonstrated that a higher level of neighborhood street-view greenery was associated with a lower fear of crime, and its relationship was mediated by perceived physical incivilities. While increasing street greenery of the micro-environment may reduce fear of crime, this paper also suggests that social factors should be considered when designing ameliorative programs.

Study on Urban Flood Control and Drainage in Beijing

2014 ◽  
Vol 1065-1069 ◽  
pp. 2381-2385
Author(s):  
Sen Guo Zhan ◽  
Bao Hui Men ◽  
Jia Jie Wu ◽  
Zheng Da Duan
Keyword(s):  
Heavy Rainfall ◽  
Flood Control ◽  
The Philippines ◽  
City Government ◽  
Urban Flood ◽  
The City ◽  
New Look

On 21 July 2012, a huge thunderstorm hit Beijing, prompting the city government to act immediately to deal with the emergency. Yet great losses were caused, exposing problems about urban flood control and drainage, and making people take a new look at them. It is not uncommon for a rainfall of such a degree to happen in Asia. Comparatively speaking, however, unlike in Beijing, fewer damages are caused in Taiwan, Japan and the Philippines given the same situation. In this article, therefore, the problems arising after a heavy rainfall and their solutions will be discussed.

Bi-directional Coupling of an Unstructured Triangular Meshes-based Integrated Hydrodynamic Model for Heterogeneous Feature-based Urban Flood Simulation

2021 ◽  
Author(s):  
Guoqiang Peng ◽  
Zhuo Zhang ◽  
Tian Zhang ◽  
Zhiyao Song ◽  
Arif Masrur
Keyword(s):  
Water Flow ◽  
Urban Areas ◽  
Overland Flow ◽  
Coupled Model ◽  
Flood Simulation ◽  
Urban Flood ◽  
Essential Condition ◽  
Flow Processes ◽  
Feature Based ◽  
Heterogeneous Feature

Abstract Urban pluvial flash floods have become a matter of widespread concern, as they severely impact people’s lives in urban areas. Hydrological and hydraulic models have been widely used for urban flood management and urban planning. Traditionally, to reduce the complexity of urban flood modelling and simulations, simplification or generalization methods have been used; for example, some models focus on the simulation of overland water flow, and some models focus on the simulation of the water flow in sewer systems. However, the water flow of urban floods includes both overland flow and sewer system flow. The overland flow processes are impacted by many different geographical features in what is an extremely spatially heterogeneous environment. Therefore, this article is based on two widely used models (SWMM and ANUGA) that are coupled to develop a bi-directional method of simulating water flow processes in urban areas. The open source overland flow model uses the unstructured triangular as the spatial discretization scheme. The unstructured triangular-based hydraulic model can be better used to capture the spatial heterogeneity of the urban surfaces. So, the unstructured triangular-based model is an essential condition for heterogeneous feature-based urban flood simulation. The experiments indicate that the proposed coupled model in this article can accurately depict surface waterlogged areas and that the heterogeneous feature-based urban flood model can be used to determine different types of urban flow processes.

Factors that affect entomophagical practices in Ghana

2017 ◽  
Vol 3 (1) ◽  
pp. 33-41 ◽  
Author(s):  
P.J. Anankware ◽  
E.A. Osekre ◽  
D. Obeng-Ofori ◽  
C.M. Khamala
Keyword(s):  
Social Factors ◽  
Urban Areas ◽  
Age Groups ◽  
Ecological Factors ◽  
Insect Species ◽  
Edible Insects ◽  
The Social ◽  
Gender Education ◽  
And Gender ◽  
Religious Reasons

This study evaluated the social and ecological factors that affect entomophagy in Ghana with a view to instigate the initiation of programmes for the use of insects for human and poultry nutrition in Africa. Two thousand questionnaires were administered to randomly selected respondents in all the ten regions of Ghana. With regards to social factors, entomophagy was found to be influenced by age, gender, education and occupation. Entomophagy is practiced across all age groups and gender in Ghana. Proportionally, 90, 78 and 74% of the aged (60+), middle aged (31-50) and the youth (18-30), respectively, were observed to consume various insect species. Ecologically, entomophagy was more pronounced in rural than urban areas. Over 87% of respondents who consume edible insects acquire them through harvesting/trapping. Four insect species were identified as feed for animals. The majority (81.6%) of the respondents consume insects as a source of protein, 9.6% for cultural reasons, 5.6% for medicinal values and 3.0 and 0.2%, respectively, for recreational and religious reasons. Gender has the least influence on entomophagy. Considering the economic, ecological and nutritional importance of edible insects in traditional Ghanaian foods, attention should be given to sustainable environmental harvesting practices.

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