Flood Risk of Embanked Areas and Potential Use of Dredge Spoils as Mitigation Measures in the Southwest Region of the Ganges‐Brahmaputra‐Meghna Delta, Bangladesh

Estimating flood hazard, vulnerability, and flood risk at the household level in the past did not fully consider all relevant parameters. The main objective of this study is to improve this drawback by developing a new comprehensive and systematic methodology considering all relevant parameters and their weighting factors. This new methodology is applied to a case study of flood inundation in a municipal area of Nan City in the Upper Nan River Basin in Thailand. Field and questionnaire surveys were carried out to collect pertinent data for input into the new methodology for estimating flood hazard, vulnerability, and risk. Designed floods for various return periods were predicted using flood simulation models for assessing flood risk. The flood risk maps constructed for the return periods of 10–500 years show a substantial increase in flood risk with the return periods. The results are consistent with past flood damages, which were significant near and along the riverbanks where ground elevation is low, population density is high, and the number of household properties are high. In conclusion, this new comprehensive methodology yielded realistic results and can be used further to assess the effectiveness of various proposed flood mitigation measures.

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Conceptualization of a Critical Infrastructure Network – Model for Flood Risk Assessments

10.5194/egusphere-egu21-922 ◽

2021 ◽

Author(s):

Roman Schotten ◽

Daniel Bachmann

Keyword(s):

Risk Analysis ◽

Flood Risk ◽

Critical Infrastructure ◽

Risk Mitigation ◽

Mitigation Measures ◽

Critical Infrastructures ◽

Flood Exposure ◽

Infrastructure Network ◽

Flood Risk Analysis ◽

De Bruijn

In flood risk analysis it is a key principle to predetermine consequences of flooding to assets, people and infrastructures. Damages to critical infrastructures are not restricted to the flooded area. The effects of directly affected objects cascades to other infrastructures, which are not directly affected by a flood. Modelling critical infrastructure networks is one possible answer to the question &#8216;how to include indirect and direct impacts to critical infrastructures?&#8217;.Critical infrastructures are connected in very complex networks. The modelling of those networks has been a basis for different purposes (Ouyang, 2014). Thus, it is a challenge to determine the right method to model a critical infrastructure network. For this example, a network-based and topology-based method will be applied (Pant et al., 2018). The basic model elements are points, connectors and polygons which are utilized to resemble the critical infrastructure network characteristics.The objective of this model is to complement the state-of-the-art flood risk analysis with a quantitative analysis of critical infrastructure damages and disruptions for people and infrastructures. These results deliver an extended basis to differentiate the flood risk assessment and to derive measures for flood risk mitigation strategies. From a technical point of view, a critical infrastructure damage analysis will be integrated into the tool ProMaIDes (Bachmann, 2020), a free software for a risk-based evaluation of flood risk mitigation measures.The data on critical infrastructure cascades and their potential linkages is scars but necessary for an actionable modelling. The CIrcle method from Deltares delivers a method for a workshop that has proven to deliver applicable datasets for identifying and connecting infrastructures on basis of cascading effects (de Bruijn et al., 2019). The data gained from CIrcle workshops will be one compound for the critical infrastructure network model.Acknowledgment: This work is part of the BMBF-IKARIM funded project PARADes (Participatory assessment of flood related disaster prevention and development of an adapted coping system in Ghana).Bachmann, D. (2020). ProMaIDeS - Knowledge Base. https://promaides.myjetbrains.comde Bruijn, K. M., Maran, C., Zygnerski, M., Jurado, J., Burzel, A., Jeuken, C., & Obeysekera, J. (2019). Flood resilience of critical infrastructure: Approach and method applied to Fort Lauderdale, Florida. Water (Switzerland), 11(3). https://doi.org/10.3390/w11030517Ouyang, M. (2014). Review on modeling and simulation of interdependent critical infrastructure systems. Reliability Engineering and System Safety, 121, 43&#8211;60. https://doi.org/10.1016/j.ress.2013.06.040Pant, R., Thacker, S., Hall, J. W., Alderson, D., & Barr, S. (2018). Critical infrastructure impact assessment due to flood exposure. Journal of Flood Risk Management, 11(1), 22&#8211;33. https://doi.org/10.1111/jfr3.12288

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Hydrodynamics of pedestrians' instability in floodwaters

Hydrology and Earth System Sciences ◽

10.5194/hess-21-515-2017 ◽

2017 ◽

Vol 21 (1) ◽

pp. 515-531 ◽

Cited By ~ 25

Author(s):

Chiara Arrighi ◽

Hocine Oumeraci ◽

Fabio Castelli

Keyword(s):

Experimental Data ◽

Froude Number ◽

Flood Risk ◽

Risk Mitigation ◽

Three Dimensional ◽

Numerical Results ◽

Mitigation Measures ◽

Dimensionless Numbers ◽

Large Variability ◽

Mobility Parameter

Abstract. People's safety is the first objective to be fulfilled by flood risk mitigation measures, and according to existing reports on the causes of casualties, most of the fatalities are due to inappropriate behaviour such as walking or driving in floodwaters. Currently available experimental data on people instability in floodwaters suffer from a large dispersion primarily depending on the large variability of the physical characteristics of the subjects. This paper introduces a dimensionless mobility parameter θP for people partly immersed in flood flows, which accounts for both flood and subject characteristics. The parameter θP is capable of identifying a unique threshold of instability depending on a Froude number, thus reducing the scatter of existing experimental data. Moreover, a three-dimensional (3-D) numerical model describing the detailed geometry of a human body and reproducing a selection of critical pairs of water depth and velocity is presented. The numerical results in terms of hydrodynamic forces and force coefficients are analysed and discussed. Both the mobility parameter θP and the numerical results hint at the crucial role of the Froude number and relative submergence as the most relevant dimensionless numbers to interpret the loss of stability. Finally, the mobility parameter θP is compared with an analogous dimensionless parameter for vehicles' instability in floodwaters, providing a new contribution to support flood risk management and educating people.

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Flood mitigation measures in an era of evolving flood risk

Journal of Flood Risk Management ◽

10.1111/jfr3.12659 ◽

2020 ◽

Vol 13 (3) ◽

Author(s):

Andrew D. Binns

Keyword(s):

Flood Risk ◽

Flood Mitigation ◽

Mitigation Measures

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A Framework Proposal for Regional-Scale Flood-Risk Assessment of Cultural Heritage Sites and Application to the Castile and León Region (Central Spain)

Water ◽

10.3390/w12020329 ◽

2020 ◽

Vol 12 (2) ◽

pp. 329 ◽

Cited By ~ 3

Author(s):

Julio Garrote ◽

Andrés Díez-Herrero ◽

Cristina Escudero ◽

Inés García

Keyword(s):

Cultural Heritage ◽

Flood Risk ◽

Flood Hazard ◽

Regional Scale ◽

Mitigation Measures ◽

Natural Phenomenon ◽

Risk Level ◽

Heritage Sites ◽

Extreme Flood ◽

The Creation

Floods, at present, may constitute the natural phenomenon with the greatest impact on the deterioration of cultural heritage, which is the reason why the study of flood risk becomes essential in any attempt to manage cultural heritage (archaeological sites, historic buildings, artworks, etc.) This management of cultural heritage is complicated when it is distributed over a wide territory. This is precisely the situation in the region of Castile and León (Spain), in which 2155 cultural heritage elements are registered in the Catalog of Cultural Heritage Sites of Castile and León, and these are distributed along the 94,226 km2 of this region. Given this scenario, the present study proposes a methodological framework of flood risk analysis for these cultural heritage sites and elements. This assessment is based on two main processing tools to be developed in addition: on the one hand, the creation of a GIS database in which to establish the spatial relationship between the cultural heritage elements and the flow-prone areas for different flood return periods and, on the other hand, the creation of a risk matrix in which different variables are regarded as associated both to flood hazard (return period, flow depth, and river flooding typology) and to flood vulnerability (construction typology, and construction structural relationship with the hydraulic environment). The combination of both tools has allowed us to establish each cultural heritage flood risk level, making its categorization of risk possible. Of all the cultural heritage sites considered, 18 of them are categorized under an Extreme flood risk level; and another 24 show a High potential flood risk level. Therefore, these are about 25% to 30% of all cultural heritage sites in Castile and León. This flood risk categorization, with a scientific basis of the cultural heritage sites at risk, makes it possible to define territories of high flood risk clustering; where local scale analyses for mitigation measures against flood risk are necessary.

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Planning Nature-Based Solutions for Urban Flood Reduction and Thermal Comfort Enhancement

Sustainability ◽

10.3390/su11226361 ◽

2019 ◽

Vol 11 (22) ◽

pp. 6361 ◽

Cited By ~ 4

Author(s):

Majidi ◽

Vojinovic ◽

Alves ◽

Weesakul ◽

Sanchez ◽

...

Keyword(s):

Heat Stress ◽

Thermal Comfort ◽

Risk Reduction ◽

Flood Risk ◽

Field Measurements ◽

Flood Mitigation ◽

Mitigation Measures ◽

Small Scale ◽

Urban Flood ◽

Flood Risk Reduction

As a consequence of climate change and urbanization, many cities will have to deal with more flooding and extreme heat stress. This paper presents a framework to maximize the effectiveness of Nature-Based Solutions (NBS) for flood risk reduction and thermal comfort enhancement. The framework involves an assessment of hazards with the use of models and field measurements. It also detects suitable implementation sites for NBS and quantifies their effectiveness for thermal comfort enhancement and flood risk reduction. The framework was applied in a densely urbanized study area, for which different small-scale urban NBS and their potential locations for implementation were assessed. The overall results show that the most effective performance in terms of flood mitigation and thermal comfort enhancement is likely achieved by applying a range of different measures at different locations. Therefore, the work presented here shows the potential of the framework to achieve an effective combination of measures and their locations, which was demonstrated on the case of the Sukhumvit area in Bangkok (Thailand). This can be particularly suitable for assessing and planning flood mitigation measures in combination with heat stress reduction.

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Potential of semi-structural and non-structural adaptation strategies to reduce future flood risk: case study for the Meuse

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-3455-2012 ◽

2012 ◽

Vol 12 (11) ◽

pp. 3455-3471 ◽

Cited By ~ 56

Author(s):

J. K. Poussin ◽

P. Bubeck ◽

J. C. J. H. Aerts ◽

P. J. Ward

Keyword(s):

Climate Change ◽

Land Use ◽

Risk Reduction ◽

Flood Risk ◽

Local Level ◽

Mitigation Strategies ◽

Policy Implications ◽

Mitigation Measures ◽

Reduction Capacity ◽

Flood Prone Areas

Abstract. Flood risk throughout Europe has increased in the last few decades, and is projected to increase further owing to continued development in flood-prone areas and climate change. In recent years, studies have shown that adequate undertaking of semi-structural and non-structural measures can considerably decrease the costs of floods for households. However, there is little insight into how such measures can decrease the risk beyond the local level, now and in the future. To gain such insights, a modelling framework using the Damagescanner model with land-use and inundation maps for 2000 and 2030 was developed and applied to the Meuse river basin, in the region of Limburg, in the southeast of the Netherlands. The research suggests that annual flood risk may increase by up to 185% by 2030 compared with 2000, as a result of combined land-use and climate changes. The independent contributions of climate change and land-use change to the simulated increase are 108% and 37%, respectively. The risk-reduction capacity of the implementation of spatial zoning measures, which are meant to limit and regulate developments in flood-prone areas, is between 25% and 45%. Mitigation factors applied to assess the potential impact of three mitigation strategies (dry-proofing, wet-proofing, and the combination of dry- and wet-proofing) in residential areas show that these strategies have a risk-reduction capacity of between 21% and 40%, depending on their rate of implementation. Combining spatial zoning and mitigation measures could reduce the total increase in risk by up to 60%. Policy implications of these results are discussed. They focus on the undertaking of effective mitigation measures, and possible ways to increase their implementation by households.

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Modeling the Impact of Building-Level Flood Mitigation Measures Made Possible by Early Flood Warnings on Community-Level Flood Loss Reduction

Buildings ◽

10.3390/buildings11100475 ◽

2021 ◽

Vol 11 (10) ◽

pp. 475

Author(s):

Omar M. Nofal ◽

John W. van de van de Lindt ◽

Harvey Cutler ◽

Martin Shields ◽

Kevin Crofton

Keyword(s):

Flood Risk ◽

Risk Model ◽

Flood Hazard ◽

Community Level ◽

Flood Mitigation ◽

Precipitation Forecast ◽

Mitigation Measures ◽

Flood Vulnerability ◽

The Impact ◽

Flood Warnings

The growing number of flood disasters worldwide and the subsequent catastrophic consequences of these events have revealed the flood vulnerability of communities. Flood impact predictions are essential for better flood risk management which can result in an improvement of flood preparedness for vulnerable communities. Early flood warnings can provide households and business owners additional time to save certain possessions or products in their buildings. This can be accomplished by elevating some of the water-sensitive components (e.g., appliances, furniture, electronics, etc.) or installing a temporary flood barrier. Although many qualitative and quantitative flood risk models have been developed and highlighted in the literature, the resolution used in these models does not allow a detailed analysis of flood mitigation at the building- and community level. Therefore, in this article, a high-fidelity flood risk model was used to provide a linkage between the outputs from a high-resolution flood hazard model integrated with a component-based probabilistic flood vulnerability model to account for the damage for each building within the community. The developed model allowed to investigate the benefits of using a precipitation forecast system that allows a lead time for the community to protect its assets and thereby decreasing the amount of flood-induced losses.

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Social Influences on Flood Preparedness and Mitigation Measures Adopted by People Living with Flood Risk

Water ◽

10.3390/w13212972 ◽

2021 ◽

Vol 13 (21) ◽

pp. 2972

Author(s):

Donald Houston ◽

Tom Ball ◽

Alan Werritty ◽

Andrew R. Black

Keyword(s):

Risk Management ◽

Flood Risk ◽

Social Inequalities ◽

Flood Risk Management ◽

Management Policy ◽

Mitigation Measures ◽

Social Differences ◽

Flood Impacts ◽

Spatial Inequalities ◽

Flood Preparedness

This paper aims to analyse evidence, based on one of the largest and most representative samples of households previously flooded or living with flood risk to date, of social patterns in a range of flood resilience traits relating to preparedness prior to a flood (e.g., property adaptations, contents insurance, etc.) and mitigations enacted during and immediately following a flood (e.g., receiving a warning, evacuation into temporary accommodation, etc.). The data were collected from a 2006 survey of 1223 households from a variety of locations across Scotland between one and twelve years after major local floods. Our analysis identifies remarkably few social differences in flood preparedness and mitigation measures, although some aspects of demography, housing and length of residence in an area, as well as personal flood history, are important. In light of this finding, we argue that social differences in vulnerability and resilience to flooding arise from deep-seated socio-economic and socio-spatial inequalities that affect exposure to flood risk and ability to recover from flood impacts. The engrained, but well-meaning, assumption in flood risk management that impoverished households and communities are lacking or deficient in flood preparedness or mitigation knowledge and capabilities is somewhat pejorative and misses fundamental, yet sometimes invisible, social stratifications play out in subtle but powerful ways to affect households’ and communities’ ability to avoid and recover from floods. We argue that general poverty and inequality alleviation measures, such as tax and welfare policy and urban and community regeneration schemes, are likely to be as, if not more, important in alleviating social inequalities in the long-term impacts of floods than social targeting of flood risk management policy.

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