Empirical flash flood vulnerability functions for residential buildings

Urban growth, extreme climate, and mismanagement are crucial controlling factors that affect flood vulnerability at wadi catchments. Therefore, this study attempts to understand the impacts of these three factors on the flash flood vulnerability in different climatic regions in Egypt. An integrated approach is presented to evaluate the urban growth from 1984 to 2019 by using Google Images and SENTINEL-2 data, and to develop hazard maps by using a rainfall-runoff-inundation model (RRI). Annual rainfall trend analysis was performed to evaluate the temporal variability trend. The hazard maps that were created were classified into three categories (low, medium, and high) and integrated with the urban growth maps to evaluate the impacts on the flood-vulnerable areas. The results show a significant increase in urban growth resulting in an increase of prone areas for flood hazards over time. However, the degree of this hazard is mainly related to growth directions. Mismanagement affects urban growth directions in both planned and unplanned growth, whether by loss of control over unplanned growth or by deficiencies in approved plans. The rainfall analysis showed that there is no explicit relationship to increases or decreases in the flood vulnerable areas. An urban planning approach is recommended for risk reduction management based on a comprehensive study considering such factors.

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A GIS-Based Support Vector Machine Model for Flash Flood Vulnerability Assessment and Mapping in China

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi8070297 ◽

2019 ◽

Vol 8 (7) ◽

pp. 297 ◽

Cited By ~ 14

Author(s):

Junnan Xiong ◽

Jin Li ◽

Weiming Cheng ◽

Nan Wang ◽

Liang Guo

Keyword(s):

Support Vector Machine ◽

Vulnerability Assessment ◽

Flash Flood ◽

Flash Floods ◽

Support Vector ◽

Land Area ◽

Analytic Hierarchy ◽

Machine Model ◽

Flood Vulnerability ◽

Development Processes

Flash floods are one of the natural disasters that threaten the lives of many people all over the world every year. Flash floods are significantly affected by the intensification of extreme climate events and interactions with exposed and vulnerable socio-economic systems impede regional development processes. Hence, it is important to estimate the loss due to flash floods before the disaster occurs. However, there are no comprehensive vulnerability assessment results for flash floods in China. Fortunately, the National Mountain Flood Disaster Investigation Project provided a foundation to develop this proposed assessment. In this study, an index system was established from the exposure and disaster reduction capability categories, and is based on analytic hierarchy process (AHP) methods. We evaluated flash flood vulnerability by adopting the support vector machine (SVM) model. Our results showed 439 counties with high and extremely high vulnerability (accounting for 10.5% of the land area and corresponding to approximately 100 million hectares (ha)), 571 counties with moderate vulnerability (accounting for 19.18% of the land area and corresponding to approximately 180 million ha), and 1128 counties with low and extremely low vulnerability (accounting for 39.43% of the land area and corresponding to approximately 370 million ha). The highly-vulnerable counties were mainly concentrated in the south and southeast regions of China, moderately-vulnerable counties were primarily concentrated in the central, northern, and southwestern regions of China, and low-vulnerability counties chiefly occurred in the northwest regions of China. Additionally, the results of the spatial autocorrelation suggested that the “High-High” values of spatial agglomeration areas mainly occurred in the Zhejiang, Fujian, Jiangxi, Hunan, Guangxi, Chongqing, and Beijing areas. On the basis of these results, our study can be used as a proposal for population and building distribution readjustments, and the management of flash floods in China.

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Flood vulnerability and risk assessment of urban traditional buildings in a heritage district of Kuala Lumpur, Malaysia

Natural Hazards and Earth System Science ◽

10.5194/nhess-20-2221-2020 ◽

2020 ◽

Vol 20 (8) ◽

pp. 2221-2241 ◽

Cited By ~ 1

Author(s):

Dina D'Ayala ◽

Kai Wang ◽

Yuan Yan ◽

Helen Smith ◽

Ashleigh Massam ◽

...

Keyword(s):

Large Scale ◽

Residential Buildings ◽

Mitigation Measures ◽

Economic Losses ◽

Exceedance Probability ◽

Kuala Lumpur ◽

Flood Vulnerability ◽

Management Actions ◽

Vulnerability Model ◽

Wide Range

Abstract. Flood hazard is increasing in frequency and magnitude in major South East Asian metropolitan areas due to fast urban development and changes in climate, threatening people's property and life. Typically, flood management actions are mostly focused on large-scale defences, such as river embankments or discharge channels or tunnels. However, these are difficult to implement in town centres without affecting the value of their heritage districts and might not provide sufficient mitigation. Therefore, urban heritage buildings may become vulnerable to flood events, even when they were originally designed and built with intrinsic resilient measures, based on the local knowledge of the natural environment and its threats at the time. Their aesthetic and cultural and economic values mean that they can represent a proportionally high contribution to losses in any event. Hence it is worth investigating more localized, tailored mitigation measures. Vulnerability assessment studies are essential to inform the feasibility and development of such strategies. In this study we propose a multilevel methodology to assess the flood vulnerability and risk of residential buildings in an area of Kuala Lumpur, Malaysia, characterized by traditional timber housing. The multiscale flood vulnerability model is based on a wide range of parameters, covering building-specific parameters, neighbourhood conditions and catchment area conditions. The obtained vulnerability index shows the ability to reflect different exposure by different building types and their relative locations. The vulnerability model is combined with high-resolution fluvial and pluvial flood maps providing scenario events with 0.1 % annual exceedance probability (AEP). A damage function of generic applicability is developed to compute the economic losses at individual building and sample levels. The study provides evidence that results obtained for a small district can be scaled up to the city level, to inform both generic and specific protection strategies.

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Assessing flash flood vulnerability using a multi-vulnerability approach

E3S Web of Conferences ◽

10.1051/e3sconf/20160708004 ◽

2016 ◽

Vol 7 ◽

pp. 08004

Author(s):

Konstantinos Karagiorgos ◽

Thomas Thaler ◽

Fotis Maris ◽

Sven Fuchs

Keyword(s):

Flash Flood ◽

Flood Vulnerability

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The Australian Great Flood of 1954: Estimating the Cost of a Similar Event in 2011

Weather Climate and Society ◽

10.1175/wcas-d-12-00018.1 ◽

2013 ◽

Vol 5 (3) ◽

pp. 199-209 ◽

Cited By ~ 3

Author(s):

Kevin M. Roche ◽

K. John McAneney ◽

Keping Chen ◽

Ryan P. Crompton

Keyword(s):

Land Use Planning ◽

Residential Buildings ◽

New South ◽

New South Wales ◽

Economic Loss ◽

Flood Vulnerability ◽

South Wales ◽

Insured Loss ◽

Insurance Penetration ◽

The Cost

Abstract As in many other parts of the globe, migration to the coast and rapid regional development in Australia is resulting in large concentrations of population and insured assets. One of the most rapidly growing regions is southeastern Queensland and northern New South Wales, an area prone to flooding. This study reexamines the Great Flood of 1954 and develops a deterministic methodology to estimate the likely cost if a similar event had occurred in 2011. This cost is estimated using council flood maps, census information, historical observations, and Risk Frontiers' proprietary flood vulnerability functions. The 1954 flood arose from heavy rainfall caused by the passage of a tropical cyclone that made landfall on 20 February near the Queensland–New South Wales border, before heading south. Responsible for some of the largest floods on record for many northern New South Wales' river catchments, it occurred prior to the availability of reliable insurance statistics and the recent escalation in property values. The lower-bound estimate of the insurance loss using current exposure and assuming 100% insurance penetration for residential buildings and contents is AU$3.5 billion, a cost that would make it the third-highest ranked insured loss due to an extreme weather event since 1967. The corresponding normalized economic loss is AU$7.6 billion but the uncertainty about this figure is high. The magnitude of these losses reflects the accumulation of exposure on the floodplains. Risk-informed land-use planning practices and improved building regulations hold the key to reducing future losses.

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Use of LSPIV in assessing urban flash flood vulnerability

Natural Hazards ◽

10.1007/s11069-017-2768-8 ◽

2017 ◽

Vol 87 (1) ◽

pp. 383-394 ◽

Cited By ~ 14

Author(s):

Nicolás Federico Guillén ◽

Antoine Patalano ◽

Carlos Marcelo García ◽

Juan Carlos Bertoni

Keyword(s):

Flash Flood ◽

Flood Vulnerability

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A physical approach on flood risk vulnerability of buildings

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-11-1411-2014 ◽

2014 ◽

Vol 11 (2) ◽

pp. 1411-1460 ◽

Cited By ~ 3

Author(s):

B. Mazzorana ◽

S. Simoni ◽

C. Scherer ◽

B. Gems ◽

S. Fuchs ◽

...

Keyword(s):

At Risk ◽

Residential Buildings ◽

Dynamic Assessment ◽

Building Envelope ◽

Economic Damage ◽

Assessment Procedure ◽

Element At Risk ◽

Vulnerability Of Buildings ◽

The Impact ◽

Vulnerability Functions

Abstract. The design of efficient hydrological risk mitigation strategies and their subsequent implementation relies on a careful vulnerability analysis of the elements exposed. Recently, extensive research efforts were undertaken to develop and refine empirical relationships linking the structural vulnerability of buildings to the impact forces of the hazard processes. These empirical vulnerability functions allow estimating the expected direct losses as a result of the hazard scenario based on spatially explicit representation of the process patterns and the elements at risk classified into defined typological categories. However, due to the underlying empiricism of such vulnerability functions, the physics of the damage generating mechanisms for a well-defined element at risk with its peculiar geometry and structural characteristics remain unveiled, and, as such, the applicability of the empirical approach for planning hazard-proof residential buildings is limited. Therefore, we propose a conceptual assessment scheme to close this gap. This assessment scheme encompasses distinct analytical steps: modelling (a) the process intensity, (b) the impact on the element at risk exposed and (c) the physical response of the building envelope. Furthermore, these results provide the input data for the subsequent damage evaluation and economic damage valuation. This dynamic assessment supports all relevant planning activities with respect to a minimisation of losses, and can be implemented in the operational risk assessment procedure.

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Flood Vulnerability Assessment of Urban Traditional Buildings in Kuala Lumpur, Malaysia

10.5194/nhess-2020-96 ◽

2020 ◽

Author(s):

Dina D'Ayala ◽

Kai Wang ◽

Yuan Yan ◽

Helen Smith ◽

Ashleigh Massam ◽

...

Keyword(s):

Vulnerability Assessment ◽

Large Scale ◽

Residential Buildings ◽

Mitigation Measures ◽

Exceedance Probability ◽

Kuala Lumpur ◽

Flood Vulnerability ◽

Management Actions ◽

Vulnerability Model ◽

Wide Range

Abstract. Flood hazard is increasing in frequency and magnitude in Southeast Asia major metropolitan areas due to the effects of fast urban development and changes in climate, threatening people's properties and life. Typically, flood management actions are mostly focused on large scale defenses, such as river embankments or discharge channels or tunnels. However, these are difficult to implement in historic centres without disturbing their heritage value, and might not provide sufficient mitigation in these areas. Therefore urban heritage buildings may be particularly exposed to flood events, even when they were originally designed and built with intrinsic resilient measures, based on the local knowledge of the natural environment and its threats at the time. Their attractiveness, cultural and economic values, means that they can represent a proportionally high contribution to losses of any event. Hence it is worth to pursue more localised, tailored, mitigation measures. Vulnerability assessment studies are essential to inform the feasibility and development of such strategies. In the present paper we propose a multi-level methodology to assess the flood vulnerability of residential buildings in an area of Kuala Lumpur Malaysia characterised by traditional timber housing. The multi-scale flood vulnerability model is based on a wide range of parameters, covering building specific parameters, neighbourhood conditions and catchment area condition. Parameters for 163 buildings were measured in detail by a field surveys integrated with Google Street View. The vulnerability model is combined with high resolution fluvial and pluvial flood maps providing likely water depths for a range of different flood return periods. The obtained vulnerability index shows ability to reflect different exposure by different building types and their relative locations. The study provides evidence that results obtained for a small district can be scaled up at city level, to inform both generic and specific protection strategies. The paper discusses these in relation to a scenario event of 0.1 % Annual Exceedance Probability (AEP), based on hydrological and hydraulic models developed for the Disaster Resilient Cities Project.

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