TY - JOUR A1 - Devitt, Laura A1 - Neal, Jeffrey A1 - Wagener, Thorsten A1 - Coxon, Gemma T1 - Uncertainty in the extreme flood magnitude estimates of large-scale flood hazard models JF - Environmental research letters : ERL / Institute of Physics N2 - The growing worldwide impact of flood events has motivated the development and application of global flood hazard models (GFHMs). These models have become useful tools for flood risk assessment and management, especially in regions where little local hazard information is available. One of the key uncertainties associated with GFHMs is the estimation of extreme flood magnitudes to generate flood hazard maps. In this study, the 1-in-100 year flood (Q100) magnitude was estimated using flow outputs from four global hydrological models (GHMs) and two global flood frequency analysis datasets for 1350 gauges across the conterminous US. The annual maximum flows of the observed and modelled timeseries of streamflow were bootstrapped to evaluate the sensitivity of the underlying data to extrapolation. Results show that there are clear spatial patterns of bias associated with each method. GHMs show a general tendency to overpredict Western US gauges and underpredict Eastern US gauges. The GloFAS and HYPE models underpredict Q100 by more than 25% in 68% and 52% of gauges, respectively. The PCR-GLOBWB and CaMa-Flood models overestimate Q100 by more than 25% at 60% and 65% of gauges in West and Central US, respectively. The global frequency analysis datasets have spatial variabilities that differ from the GHMs. We found that river basin area and topographic elevation explain some of the spatial variability in predictive performance found in this study. However, there is no single model or method that performs best everywhere, and therefore we recommend a weighted ensemble of predictions of extreme flood magnitudes should be used for large-scale flood hazard assessment. KW - large-scale flood hazard models KW - global hydrological model KW - flood risk Y1 - 2021 U6 - https://doi.org/10.1088/1748-9326/abfac4 SN - 1748-9326 VL - 16 IS - 6 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Bryant, Seth A1 - Davies, Evan A1 - Sol, David A1 - Davis, Sandy T1 - The progression of flood risk in southern Alberta since the 2013 flood JF - Journal of flood risk management N2 - After a century of semi-restricted floodplain development, Southern Alberta, Canada, was struck by the devastating 2013 Flood. Aging infrastructure and limited property-level floodproofing likely contributed to the $4-6 billion (CAD) losses. Following this catastrophe, Alberta has seen a revival in flood management, largely focused on structural protections. However, concurrent with the recent structural work was a 100,000+ increase in Calgary's population in the 5 years following the flood, leading to further densification of high-hazard areas. This study implements the novel Stochastic Object-based Flood damage Dynamic Assessment (SOFDA) model framework to quantify the progression of the direct-damage flood risk in a mature urban neighborhood after the 2013 Flood. Five years of remote-sensing data, property assessment records, and inundation simulations following the flood are used to construct the model. Results show that in these 5 years, vulnerability trends (like densification) have increased flood risk by 4%; however, recent structural mitigation projects have reduced overall flood risk by 47% for this case study. These results demonstrate that the flood management revival in Southern Alberta has largely been successful at reducing flood risk; however, the gains are under threat from continued development and densification absent additional floodproofing regulations. KW - Calgary KW - depth-damage functions KW - expected annual damages KW - flood risk KW - model KW - property level protection measures KW - risk analysis KW - risk dynamics Y1 - 2022 U6 - https://doi.org/10.1111/jfr3.12811 SN - 1753-318X VL - 15 IS - 3 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Hudson, Paul T1 - The affordability of flood risk property-level adaptation measures JF - Risk Analysis N2 - The affordability of property-level adaptation measures against flooding is crucial due to the movement toward integrated flood risk management, which requires the individuals threatened by flooding to actively manage flooding. It is surprising to find that affordability is not often discussed, given the important roles that affordability and social justice play regarding flood risk management. This article provides a starting point for investigating the potential rate of unaffordability of flood risk property-level adaptation measures across Europe using two definitions of affordability, which are combined with two different affordability thresholds from within flood risk research. It uses concepts of investment and payment affordability, with affordability thresholds based on residual income and expenditure definitions of unaffordability. These concepts, in turn, are linked with social justice through fairness concerns, in that, all should have equal capability to act, of which affordability is one avenue. In doing so, it was found that, for a large proportion of Europe, property owners generally cannot afford to make one-time payment of the cost of protective measures. These can be made affordable with installment payment mechanisms or similar mechanisms that spread costs over time. Therefore, the movement toward greater obligations for flood-prone residents to actively adapt to flooding should be accompanied by socially accessible financing mechanisms. KW - Affordability KW - flood risk KW - social justice KW - risk reduction Y1 - 2020 U6 - https://doi.org/10.1111/risa.13465 SN - 0272-4332 SN - 1539-6924 VL - 40 IS - 6 SP - 1151 EP - 1167 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Hudson, Paul A1 - Hagedoorn, Liselotte A1 - Bubeck, Philip T1 - Potential linkages between social capital, flood risk perceptions, and self-efficacy JF - International journal of disaster risk science N2 - A growing focus is being placed on both individuals and communities to adapt to flooding as part of the Sendai Framework for Disaster Risk Reduction 2015-2030. Adaptation to flooding requires sufficient social capital (linkages between members of society), risk perceptions (understanding of risk), and self-efficacy (self-perceived ability to limit disaster impacts) to be effective. However, there is limited understanding of how social capital, risk perceptions, and self-efficacy interact. We seek to explore how social capital interacts with variables known to increase the likelihood of successful adaptation. To study these linkages we analyze survey data of 1010 respondents across two communities in Thua Tien-Hue Province in central Vietnam, using ordered probit models. We find positive correlations between social capital, risk perceptions, and self-efficacy overall. This is a partly contrary finding to what was found in previous studies linking these concepts in Europe, which may be a result from the difference in risk context. The absence of an overall negative exchange between these factors has positive implications for proactive flood risk adaptation. KW - flood risk KW - protection motivation theory KW - risk perceptions KW - social KW - capital KW - self-efficacy KW - Vietnam Y1 - 2020 U6 - https://doi.org/10.1007/s13753-020-00259-w SN - 2095-0055 SN - 2192-6395 VL - 11 IS - 3 SP - 251 EP - 262 PB - Springer CY - Berlin ER - TY - JOUR A1 - Philips, Andrea A1 - Walz, Ariane A1 - Bergner, Andreas G. N. A1 - Gräff, Thomas A1 - Heistermann, Maik A1 - Kienzler, Sarah A1 - Korup, Oliver A1 - Lipp, Torsten A1 - Schwanghart, Wolfgang A1 - Zeilinger, Gerold T1 - Immersive 3D geovisualization in higher education JF - Journal of geography in higher education N2 - In this study, we investigate how immersive 3D geovisualization can be used in higher education. Based on MacEachren and Kraak's geovisualization cube, we examine the usage of immersive 3D geovisualization and its usefulness in a research-based learning module on flood risk, called GEOSimulator. Results of a survey among participating students reveal benefits, such as better orientation in the study area, higher interactivity with the data, improved discourse among students and enhanced motivation through immersive 3D geovisualization. This suggests that immersive 3D visualization can effectively be used in higher education and that 3D CAVE settings enhance interactive learning between students. KW - immersive 3D geovisualization KW - 3D CAVE KW - higher education KW - learning success KW - student survey KW - flood risk Y1 - 2015 U6 - https://doi.org/10.1080/03098265.2015.1066314 SN - 0309-8265 SN - 1466-1845 VL - 39 IS - 3 SP - 437 EP - 449 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Sairam, Nivedita A1 - Schroeter, Kai A1 - Rözer, Viktor A1 - Merz, Bruno A1 - Kreibich, Heidi T1 - Hierarchical Bayesian Approach for Modeling Spatiotemporal Variability in Flood Damage Processes JF - Water resources research N2 - Flood damage processes are complex and vary between events and regions. State-of-the-art flood loss models are often developed on the basis of empirical damage data from specific case studies and do not perform well when spatially and temporally transferred. This is due to the fact that such localized models often cover only a small set of possible damage processes from one event and a region. On the other hand, a single generalized model covering multiple events and different regions ignores the variability in damage processes across regions and events due to variables that are not explicitly accounted for individual households. We implement a hierarchical Bayesian approach to parameterize widely used depth-damage functions resulting in a hierarchical (multilevel) Bayesian model (HBM) for flood loss estimation that accounts for spatiotemporal heterogeneity in damage processes. We test and prove the hypothesis that, in transfer scenarios, HBMs are superior compared to generalized and localized regression models. In order to improve loss predictions for regions and events for which no empirical damage data are available, we use variables pertaining to specific region- and event-characteristics representing commonly available expert knowledge as group-level predictors within the HBM. KW - flood risk KW - flood loss model transfer KW - multilevel probabilistic flood loss model Y1 - 2019 U6 - https://doi.org/10.1029/2019WR025068 SN - 0043-1397 SN - 1944-7973 VL - 55 IS - 10 SP - 8223 EP - 8237 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Mester, Benedikt A1 - Willner, Sven N. A1 - Frieler, Katja A1 - Schewe, Jacob T1 - Evaluation of river flood extent simulated with multiple global hydrological models and climate forcings JF - Environmental research letters : ERL / Institute of Physics N2 - Global flood models (GFMs) are increasingly being used to estimate global-scale societal and economic risks of river flooding. Recent validation studies have highlighted substantial differences in performance between GFMs and between validation sites. However, it has not been systematically quantified to what extent the choice of the underlying climate forcing and global hydrological model (GHM) influence flood model performance. Here, we investigate this sensitivity by comparing simulated flood extent to satellite imagery of past flood events, for an ensemble of three climate reanalyses and 11 GHMs. We study eight historical flood events spread over four continents and various climate zones. For most regions, the simulated inundation extent is relatively insensitive to the choice of GHM. For some events, however, individual GHMs lead to much lower agreement with observations than the others, mostly resulting from an overestimation of inundated areas. Two of the climate forcings show very similar results, while with the third, differences between GHMs become more pronounced. We further show that when flood protection standards are accounted for, many models underestimate flood extent, pointing to deficiencies in their flood frequency distribution. Our study guides future applications of these models, and highlights regions and models where targeted improvements might yield the largest performance gains. KW - global flood model KW - validation KW - model intercomparison KW - flood risk KW - global hydrological model Y1 - 2021 U6 - https://doi.org/10.1088/1748-9326/ac188d SN - 1748-9326 VL - 16 IS - 9 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Hudson, Paul A1 - Pham, My A1 - Bubeck, Philip T1 - An evaluation and monetary assessment of the impact of flooding on subjective well-being across genders in Vietnam JF - Climate & development N2 - The intangible impacts of floods on welfare are not well investigated, even though they are important aspects of welfare. Moreover, flooding has gender based impacts on welfare. These differing impacts create a gender based flood risk resilience gap. We study the intangible impacts of flood risk on the subjective well-being of residents in central Vietnam. The measurement of intangible impacts through subjective well-being is a growing field within flood risk research. We find an initial drop in welfare through subjective well-being across genders when a flood is experienced. Male respondents tended to recover their welfare losses by around 80% within 5 years while female respondents were associated with a welfare recovery of around 70%. A monetization of the impacts floods have on an individual’s subjective well-being shows that for the average female respondent, between 41% to 86% of annual income would be required to compensate subjective well-being losses after 5 years of experiencing a flood. The corresponding value for males is 30% to 57% of annual income. This shows that the intangible impacts of flood risk are important (across genders) and need to be integrated into flood (or climate) risk assessments to develop more socially appropriate risk management strategies. KW - Subjective well-being KW - flood risk KW - welfare KW - gender KW - resilience KW - intangible impacts Y1 - 2019 U6 - https://doi.org/10.1080/17565529.2019.1579698 SN - 1756-5529 SN - 1756-5537 VL - 11 IS - 7 SP - 623 EP - 637 PB - Routledge, Taylor & Francis Group CY - Abingdon ER -