On the Influence of the Main Floor Layout of Buildings in Economic Flood Risk Assessment: Results from Central Spain

Multiple studies have been carried out on the correct estimation of the damages (direct tangible losses) associated with floods. However, the complex analysis and the multitude of variables conditioning the damage estimation, as well as the uncertainty in their estimation, make it difficult, even today, to reach one single, complete solution to this problem. In no case has the influence that the topographic relationship between the main floor of a residential building and the surrounding land have in the estimation of flood economic damage been analysed. To carry out this analysis, up to a total of 28 magnitude–damage functions (with different characteristics and application scales) were selected on which the effect of over-elevation and under-elevation of the main floor of the houses was simulated (at intervals of 20 cm, between −0.6 and +1 metre). According to each of the two trends, an overestimation or underestimation of flood damage was observed. This pattern was conditioned by the specific characteristics of each magnitude–damage function, meaning that the percentage of damage became asymptotic from a certain flow depth value. In a real scenario, the consideration of this variable (as opposed to its non-consideration) causes an average variation in the damage estimation around 30%. Based on these results, the analysed variable can be considered as (1) another main source of uncertainty in the correct estimation of flood damage, and (2) an essential variable to take into account in a flood damage analysis for the correct estimation of loss.

Download Full-text

Development of Flood Damage Estimation Model for Agriculture – Case Study in the Bago Floodplain, Myanmar

Journal of Disaster Research ◽

10.20965/jdr.2020.p0242 ◽

2020 ◽

Vol 15 (3) ◽

pp. 242-255

Author(s):

Shelly Win ◽

Win Win Zin ◽

Akiyuki Kawasaki ◽

◽

Keyword(s):

Questionnaire Survey ◽

Flood Damage ◽

Damage Function ◽

Economic Damage ◽

Damage Estimation ◽

Estimation Model ◽

Damage Cost ◽

Extreme Flood ◽

Spatially Distributed ◽

Flood Damage Estimation

This paper introduces an integrated model that combines the Rainfall Runoff Inundation (RRI) and spatially distributed flood damage estimation models. There are three steps for fulfilling this purpose. The first step is the accomplishment of RRI model for the floodplain region. The second step is a questionnaire survey to analyze the economic damage to affected population and properties caused by the past flooding events; this step aims to estimate the different levels of agricultural damage cost. Finally, the economic flood damage estimation model was developed for the agricultural areas by using the stage-damage function models which were established by the multiple regression analysis of questionnaire survey data. The model results were expressed through spatially distributed flood damage maps for extreme flood events, such as those in 2014, 2015, and 2018. The results were validated by collecting damage cost data from the Department of Agricultural Lands Management and Statistics (DALMS). The final findings included comparative scenarios for reducing damage cost in the most effective and realistic way. The output product was the agricultural damage estimation model. For further research, the model was recommended for application in other study areas with different flood scales.

Download Full-text

Estimation of an absolute flood damage curve based on an Austrian case study under a dam breach scenario

Natural Hazards and Earth System Science ◽

10.5194/nhess-10-881-2010 ◽

2010 ◽

Vol 10 (4) ◽

pp. 881-894 ◽

Cited By ~ 24

Author(s):

F. Prettenthaler ◽

P. Amrusch ◽

C. Habsburg-Lothringen

Keyword(s):

Future Development ◽

Damage Assessment ◽

Field Data ◽

Flood Damage ◽

Damage Function ◽

Damage Potential ◽

Dam Breach ◽

Damage Functions ◽

Austrian Case

Abstract. To date, in Austria no empirical assessment of absolute damage curves has been realized on the basis of detailed information on flooded buildings due to a dam breach, presumably because of the lack of data. This paper tries to fill this gap by estimating an absolute flood-damage curve, based on data of a recent flood event in Austria in 2006. First, a concise analysis of the case study area is conducted, i.e., the maximum damage potential is identified by using raster-based GIS. Thereafter, previous literature findings on existing flood-damage functions are considered in order to determine a volume-water damage function that can be used for further flood damage assessment. Finally, the flood damage function is cross validated and applied in prediction of damage potential in the study area. For future development of the estimated flood damage curve, and to aid more general use, we propose verification against field data on damage caused by natural waves in rivers.

Download Full-text

Damage functions for climate-related hazards: unification and uncertainty analysis

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-3-6845-2015 ◽

2015 ◽

Vol 3 (11) ◽

pp. 6845-6881 ◽

Cited By ~ 1

Author(s):

B. F. Prahl ◽

D. Rybski ◽

M. Boettle ◽

J. P. Kropp

Keyword(s):

Climate Change Impacts ◽

Flood Damage ◽

Damage Function ◽

Storm Damage ◽

Damage Functions ◽

Single Item ◽

Universal Approach ◽

The Common ◽

Flooding Events

Abstract. Most climate change impacts manifest in the form of natural hazards. For example, sea-level rise and changes in storm climatology are expected to increase the frequency and magnitude of flooding events. In practice there is a need for comprehensive damage assessment at an intermediate level of complexity. Answering this need, we reveal the common grounds of macroscale damage functions employed in storm damage, coastal-flood damage, and heat mortality assessment. The universal approach offers both bottom-up and top-down damage evaluation, employing either an explicit or an implicit portfolio description. Putting emphasis on the treatment of data uncertainties, we perform a sensitivity analysis across different scales. We find that the behaviour of intrinsic uncertainties on the microscale level (i.e. single item) does still persist on the macroscale level (i.e. portfolio). Furthermore, the analysis of uncertainties can reveal their specific relevance, allowing for simplification of the modelling chain. Our results shed light on the role of uncertainties and provide useful insight for the application of a unified damage function.

Download Full-text

Flood damage estimation beyond stage-damage functions: an Australian example

Journal of Flood Risk Management ◽

10.1111/j.1753-318x.2009.01058.x ◽

2010 ◽

Vol 3 (1) ◽

pp. 88-96 ◽

Cited By ~ 54

Author(s):

M.H. Middelmann-Fernandes

Keyword(s):

Flood Damage ◽

Damage Estimation ◽

Damage Functions ◽

Flood Damage Estimation

Download Full-text

Flood vulnerability assessment: A critical comparison between site derived, national and international depth-damage functions and their use in assessing flood risk in Malaysia

10.5194/egusphere-egu21-12731 ◽

2021 ◽

Author(s):

Balqis M. Rehan ◽

Paul Sayers ◽

A. Ulwan M. Alayuddin ◽

M. Fadhil M. Ghamrawi ◽

James D. Miller ◽

...

Keyword(s):

Flood Risk ◽

Flood Hazard ◽

Flood Damage ◽

Damage Function ◽

Kuala Lumpur ◽

Investment Planning ◽

Damage Functions ◽

Flood Vulnerability ◽

Site Specific ◽

Flood Vulnerability Assessment

<p>Damage functions are widely used to determine flood losses. National and international published damage functions are often used with little scrutiny or validation at local scales; a lack of understanding that unquestionably adds uncertainty to national flood risk assessment and investment planning. This paper examines the differences in aggregate flood damage estimates based on damage functions derived locally using local surveys and questionnaires, published national sector-based damage functions and land-use based damage functions published for Malaysia in the international literature. The paper is presented in two parts: firstly, the construction of a damage function from site-specific post-event flood surveys (covering a range of building types and flood hazard variables) and secondly, the comparison of these locally derived function with available national and international functions. A 0.05 km<sup>2</sup> residential area located in Kuala Lumpur, Malaysia, which consists of sparsely located houses was selected for the study. It was used to drive the site-specific damage function and an associated estimate of flood damage for a range of observed and modelled flood events. The results show that at higher depths, the use of the site-specific function suggest an aggregate damage of approximately twice than an estimate based on national functions but much less (less than 100%) than would be estimated based on international published functions. The paper concludes that the international published damage functions should be used with care and condition using local (where possible) or national understanding of flood damages to avoid a significant over estimation of losses.</p>

Download Full-text

About the influence of elevation model quality and small-scale damage functions on flood damage estimation

Natural Hazards and Earth System Science ◽

10.5194/nhess-11-3327-2011 ◽

2011 ◽

Vol 11 (12) ◽

pp. 3327-3334 ◽

Cited By ~ 27

Author(s):

M. Boettle ◽

J. P. Kropp ◽

L. Reiber ◽

O. Roithmeier ◽

D. Rybski ◽

...

Keyword(s):

Influencing Factor ◽

Storm Surges ◽

Flood Damage ◽

Damage Function ◽

Building Damage ◽

Small Scale ◽

Model Quality ◽

Damage Functions ◽

Elevation Model

Abstract. The assessment of coastal flood risks in a particular region requires the estimation of typical damages caused by storm surges of certain characteristics and annualities. Although the damage depends on a multitude of factors, including flow velocity, duration of flood, precaution, etc., the relationship between flood events and the corresponding average damages is usually described by a stage-damage function, which considers the maximum water level as the only damage influencing factor. Starting with different (microscale) building damage functions we elaborate a macroscopic damage function for the entire case study area Kalundborg (Denmark) on the basis of multiple coarse-graining methods and assumptions of the hydrological connectivity. We find that for small events, the macroscopic damage function mostly depends on the properties of the elevation model, while for large events it strongly depends on the assumed building damage function. In general, the damage in the case study increases exponentially up to a certain level and then less steep.

Download Full-text

Standard residential flood damage functions for South African conditions

Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie ◽

10.4102/satnt.v26i1.122 ◽

2007 ◽

Vol 26 (1) ◽

pp. 26-36 ◽

Cited By ~ 1

Author(s):

Gawie De Villiers ◽

Giel Viljoen ◽

Herman Booysen

Keyword(s):

Risk Management ◽

Disaster Management ◽

Disaster Risk ◽

Flood Damage ◽

Damage Function ◽

Disaster Risk Management ◽

Damage Functions ◽

Planning Processes ◽

Summary Statement ◽

The University

Disaster risk management is an integral part of a scientific approach to disaster management. It refers to integrated, multi-sectoral, multi-disciplinary, organizational and operational planning processes and skills to mitigate disasters. Application of the approach necessitates disaster risk analysis, requiring flood damage functions in the case of floods. A flood damage function can be described mathematically, tabularly or graphically and refers to the relationship between flood characteristics like depth and/or speed of floodwater and flood damage to a specific land use type. Research conducted at the University of the Free State indicated the value of standard residential flood damage functions and the necessity for periodic updating to secure contemporary relevance. This article focuses on updating of the latter. The article starts with an introduction to put the development, use and maintenance of standard residential flood damage functions in context with regard to the latest views on disaster risk management, risk assessment, disaster management legislation in South Africa and a computer model TEWA, in which the flood damage functions are used. Aspects that can affect flood damage are briefly discussed, followed by sections on the development and upgrading of structural flood damage functions for formal housing as well as functions for determining damage to housing contents. The development of residential flood damage functions that can be applied nationally forms the main part of the paper and is followed by a brief summary statement.

Download Full-text

Are new open building data useful for flood vulnerability modelling?

10.5194/nhess-2020-206 ◽

2020 ◽

Author(s):

Marco Cerri ◽

Max Steinhausen ◽

Heidi Kreibich ◽

Kai Schröter

Keyword(s):

Residential Buildings ◽

Open Data ◽

Residential Building ◽

Predictive Performance ◽

Flood Damage ◽

Building Vulnerability ◽

Damage Functions ◽

Data Set ◽

Flood Vulnerability ◽

Spatial Measures

Abstract. Flood risk modelling aims to quantify the probability of flooding and the resulting consequences for exposed elements. The assessment of flood damage is a core task that requires the description of complex flood damage processes including the influences of flooding intensity and vulnerability characteristics. Multi-variable modelling approaches are better suited for this purpose than simple stage-damage functions. However, multi-variable flood vulnerability models also often have problems to predict damage for regions other than those for which they have been developed. A transfer of vulnerability models usually results in a drop of model predictive performance. Here we investigate the question of whether data from the open data source OpenStreetMap is suitable to model flood vulnerability of residential buildings and whether the underlying standardized data model is helpful to transfer models across regions. We develop a new data set by calculating numerical spatial measures for residential building footprint geometries and combine these variables with an empirical data set of observed flood damage. From this data set random forest regression models are learned using regional sub-sets and are tested for predicting flood damage in other regions. This regional split-sample validation approach reveals that the predictive performance of models based on OpenStreetMap data is comparable to alternative multi-variable models, which use comprehensive and detailed information about preparedness, socio-economic status and other aspects of residential building vulnerability. However, our results show that using numerical spatial measures derived from OpenStreetMap building geometries does not resolve all problems of model transfer. Still, we conclude that these variables are useful proxies for flood vulnerability modelling, because these data are consistent, openly accessible, and thus make it easier and more cost-effective to transfer vulnerability models to other regions.

Download Full-text