scholarly journals Multivariate flood risk assessment based on the secondary return period

2015 ◽  
Vol 27 (2) ◽  
pp. 352-360 ◽  
Author(s):  
HUANG Qiang ◽  
◽  
CHEN Zishen
Keyword(s):  
Risk Assessment ◽  
Return Period ◽  
Flood Risk ◽  
Flood Risk Assessment

scholarly journals Climate Change, Flood Risk Prediction and Acute Gastrointestinal Infection in the Republic of Ireland, 2008-2017

2020 ◽  
Author(s):  
Martin Boudou ◽  
Eimear Cleary ◽  
Paul Hynds ◽  
Jean O'Dwyer ◽  
Patricia Garvey ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Return Period ◽  
Flood Risk ◽  
Geographical Information ◽  
Risk Exposure ◽  
Flood Risk Assessment ◽  
Republic Of Ireland ◽  
Risk Probability ◽  
The Republic

<p>Environmentally associated infectious diseases, including those driven by extreme weather events, represent a critical challenge for public health as their source and transmission are frequently sporadic and associated mechanisms often not well understood. Over the past decade, the Republic of Ireland (ROI) has persistently reported the highest incidence of confirmed verotoxigenic E. coli (VTEC) and cryptosporidiosis infection in the European Union. Moreover, recent climate projections indicate that the incidence, severity and timing of extreme rainfall events and flooding will increase dramatically over the next century, with Ireland forecast to be the second most affected European country with respect to the mean proportion of the population residing in flood-prone areas by 2100. This study aimed to assess the association(s) between potential flood risk exposure and the spatial occurrence of confirmed VTEC and cryptosporidiosis infection in Ireland over a 10-year period (2008-2017).</p><p>In 2012, the Irish Office of Public Works (OPW) initiated the National Catchment Flood Risk Assessment and Management (CFRAM) Programme within the framework of the Flood Directive (2007/60/CE), with high-resolution flood maps produced for coastal and fluvial risks and three risk scenarios based on calculated return periods (low, medium and high probability). Small area identifiers (national census area centroids) were used to attach anonymised spatially referenced case data to CFRAM polygons using Geographical Information Systems (GIS) to produce an anonymised dataframe of confirmed infection events linked to geographically explicit flood risk attributes. Generalised linear modelling with binary link functions (infection presence/absence) were used to calculate probabilistic odds ratios (OR) between flood risk (presence/absence and scenarios) and confirmed human infection.</p><p>Preliminary results indicate a clear relationship between both infections and hydrological risk. Over one third of all infection cases were reported within areas exposed to flood risk (VTEC 948/2755 cases; cryptosporidiosis 1548/4509 cases). Census areas categorised by a high (10-year Return Period) fluvial flood risk probability exhibited significantly higher incidence rates for both VTEC (OR: 1.83, P = 0.0003) and cryptosporidiosis (OR: 1.80, P = 0.0015). Similarly, areas characterised by low (1000-year Return Period) coastal flood risk probability were over twice as likely to report ≥1 confirmed case of cryptosporidiosis during the study period (OR: 2.2, P= 0.003). Space-time scan statistics (temporally-specific spatial autocorrelation) indicate an unseasonal peak of cryptosporidiosis cases occurring during April 2016, a majority of which took place within or adjacent to high flood risk areas (56% of total cases), revealing a potential relationship with the exceptional flooding events experienced during winter 2015-2016 (November-January). Further work will seek to identify the individual/combined flood risk (CFRAM) elements most significantly associated with the incidence of infections.</p><p>Flood risk assessment mapping may represent an innovative approach to assessing the human health impacts of flood risk exposure and climate change. The outcomes of this study will contribute to predictive modelling of VTEC and cryptosporidiosis in Ireland, thus aiding surveillance and control of these diseases in the future, and the causative nature of regional hydrology and climate.   </p>

scholarly journals Flood Hazard, Vulnerability and Risk Assessment for Different Land Use Classes Using a Flow Model

2019 ◽  
Vol 4 (1) ◽  
pp. 225-244 ◽  
Author(s):  
Md Abdullah Al Baky ◽  
Muktarun Islam ◽  
Supria Paul
Keyword(s):  
Risk Assessment ◽  
Critical Point ◽  
Return Period ◽  
Flood Risk ◽  
Flood Hazard ◽  
Flow Simulation ◽  
Flood Risk Assessment ◽  
Damage Functions ◽  
Flood Vulnerability ◽  
Different Levels

AbstractThis study is concerned with flood risk that can be assessed by integrating GIS, hydraulic modelling and required field information. A critical point in flood risk assessment is that while flood hazard is the same for a given area in terms of intensity, the risk could be different depending on a set of conditions (flood vulnerability). Clearly, risk is a function of hazard and vulnerability. This study aims to introducing a new approach of assessing flood risk, which successfully addresses this above-mentioned critical issue. The flood risk was assessed from flood hazard and vulnerability indices. Two-dimensional flood flow simulation was performed with Delft3D model to compute floodplain inundation depths for hazard assessment. For the purpose of flood vulnerability assessment, elements at risk and flood damage functions were identified and assessed, respectively. Then, finally flood risk was assessed first by combining replacement values assessed for the elements and then using the depth–damage function. Applying this approach, the study finds that areas with different levels of flood risk do not always increase with the increase in return period of flood. However, inundated areas with different levels of flood depth always increase with the increase in return period of flood. The approach for flood risk assessment adopted in this study successfully addresses the critical point in flood risk study, where flood risk can be varied even after there is no change in flood hazard intensity.

scholarly journals Maximising the usefulness of flood risk assessment for the River Vistula in Warsaw

2013 ◽  
Vol 13 (12) ◽  
pp. 3443-3455 ◽  
Author(s):  
A. Kiczko ◽  
R. J. Romanowicz ◽  
M. Osuch ◽  
E. Karamuz
Keyword(s):  
Risk Assessment ◽  
Return Period ◽  
Flood Risk ◽  
Flow Model ◽  
Flood Inundation ◽  
Flood Risk Assessment ◽  
Flood Wave ◽  
Flow Routing ◽  
Risk Maps ◽  
Inundation Extent

Abstract. The derivation of the flood risk maps requires an estimation of maximum inundation extent for a flood with a given return period, e.g. 100 or 500 yr. The results of numerical simulations of flood wave propagation are used to overcome the lack of relevant observations. In practice, deterministic 1-D models are used for that purpose. The solution of a 1-D model depends on the initial and boundary conditions and estimates of model parameters based on the available noisy observations. Therefore, there is a large uncertainty involved in the derivation of flood risk maps using a single realisation of a flow model. Bayesian conditioning based on multiple model simulations can be used to quantify this uncertainty; however, it is too computer-time demanding to be applied in flood risk assessment in practice, without further flow routing model simplifications. We propose robust and feasible methodology for estimating flood risk. In order to decrease the computation times the assumption of a gradually varied flow and the application of a steady state flow routing model is introduced. The aim of this work is an analysis of the influence of those simplifying assumptions and uncertainty of observations and modelling errors on flood inundation mapping and a quantitative comparison with deterministic flood extent maps. Apart from the uncertainty related to the model structure and its parameters, the uncertainty of the estimated flood wave with a specified probability of return period (so-called 1-in-10 yr, or 1-in-100 yr flood) is also taken into account. In order to derive the uncertainty of inundation extent conditioned on the design flood, the probabilities related to the design wave and flow model uncertainties are integrated. In the present paper that integration is done whilst taking into account the dependence of roughness coefficients on discharge. The roughness is parameterised based on maximum annual discharges. This approach allows for the relationship between flood extent and flow values to be derived, thus giving a cumulative assessment of flood risk. The methods are illustrated using the Warsaw reach of the River Vistula as a case study. The results indicate that deterministic and stochastic flood inundation maps cannot be quantitatively compared. We show that the proposed simplified approach to flood risk assessment can be applied even when breaching of the embankment occurs, with the condition that the flooded area is small enough to be filled rapidly.

scholarly journals Maximizing the usefulness of flood risk assessment for the River Vistula in Warsaw

2013 ◽  
Vol 1 (3) ◽  
pp. 2695-2730
Author(s):  
A. Kiczko ◽  
R. J. Romanowicz ◽  
M. Osuch ◽  
E. Karamuz
Keyword(s):  
Risk Assessment ◽  
Wave Propagation ◽  
Return Period ◽  
Flood Risk ◽  
Model Parameters ◽  
Flood Risk Assessment ◽  
Flood Wave ◽  
Flow Routing ◽  
Risk Maps ◽  
Inundation Extent

Abstract. The derivation of flood risk maps requires an estimation of maximum inundation extent for a flood with a given return period, e.g. 100 or 500 yr. The results of numerical simulations of flood wave propagation are used to overcome the lack of relevant observations. In practice, deterministic 1-D models are used for flow routing, giving a simplified image of flood wave propagation. The solution of a 1-D model depends on the initial and boundary conditions and estimates of model parameters which are usually identified using the inverse problem based on the available noisy observations. Therefore, there is a large uncertainty involved in the derivation of flood risk maps. Bayesian conditioning based on multiple model simulations can be used to quantify this uncertainty; however, it is too computer-time demanding to be applied in flood risk assessment in practice, without further flow routing model simplifications. In order to speed up the computation times the assumption of a gradually varied flow and the application of a steady state flow routing model may be introduced. The aim of this work is an analysis of the influence of those simplifying model assumptions and uncertainty of observations and modelling errors on flood inundation mapping and a quantitative comparison with deterministic flood extent maps. Apart from the uncertainty related to the model structure and its parameters, the uncertainty of the estimated flood wave with a specified probability of return period (so-called 1-in-10 yr, or 1-in-100 yr flood) is also taken into account. In order to derive the uncertainty of inundation extent conditioned on the design flood wave, the probabilities related to the design wave and flow model uncertainties are integrated. In the present paper we take into account the dependence of roughness coefficients on discharge. The roughness is parameterised based on the available observed historical flood waves. The approach presented allows for the relationship between flood extent and flow values to be derived thus giving a cumulative assessment of flood risk. The methods are illustrated using the Warsaw reach of the River Vistula as a case study. The results indicate that the uncertainties have a substantial influence on flood risk assessment.

Flood Risk Assessment and Forecasting for the Ganges-Brahmaputra-Meghna River Basins

10.1596/28574 ◽  
2017 ◽  
Author(s):  
Satya Priya ◽  
William Young ◽  
Thomas Hopson ◽  
Ankit Avasthi
Keyword(s):  
Risk Assessment ◽  
Flood Risk ◽  
River Basins ◽  
Flood Risk Assessment ◽  
The Ganges

scholarly journals Method for fluvial and pluvial flood risk assessment in rural settlements

MethodsX ◽  
2021 ◽  
pp. 101463
Author(s):  
Maurizio Tiepolo ◽  
Elena Belcore ◽  
Sarah Braccio ◽  
Souradji Issa ◽  
Giovanni Massazza ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Flood Risk ◽  
Flood Risk Assessment ◽  
Rural Settlements

scholarly journals An Integrated Flood Risk Assessment Model for Cities Located in the Transitional Zone between Taihang Mountains and North China Plain: A Case Study in Shijiazhuang, Hebei, China

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 104 ◽  
Author(s):  
Qiang Liu ◽  
Hongmao Yang ◽  
Min Liu ◽  
Rui Sun ◽  
Junhai Zhang
Keyword(s):  
Risk Assessment ◽  
Flood Risk ◽  
North China Plain ◽  
North China ◽  
Transitional Zone ◽  
Assessment Model ◽  
Analysis Tool ◽  
Risk Assessment Model ◽  
Flood Risk Assessment ◽  
Risk Map

Cities located in the transitional zone between Taihang Mountains and North China plain run high flood risk in recent years, especially urban waterlogging risk. In this paper, we take Shijiazhuang, which is located in this transitional zone, as the study area and proposed a new flood risk assessment model for this specific geographical environment. Flood risk assessment indicator factors are established by using the digital elevation model (DEM), along with land cover, economic, population, and precipitation data. A min-max normalization method is used to normalize the indices. An analytic hierarchy process (AHP) method is used to determine the weight of each normalized index and the geographic information system (GIS) spatial analysis tool is adopted for calculating the risk map of flood disaster in Shijiazhuang. This risk map is consistent with the reports released by Hebei Provincial Water Conservancy Bureau and can provide reference for flood risk management.

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