Building vulnerability to hydro-geomorphic hazards: Estimating damage probability from qualitative vulnerability assessment using logistic regression

Abstract

38The focus of this study is an analysis of building vulnerability through investigating impacts 45This study assesses the aspects of building design and site specific environmental hazard proxy in areas where more detailed hydrodynamic modeling data is not available. 50Building design and site-specific environmental conditions determine the physical vulnerability. 51The mathematical approach considers both physical vulnerability and hazard related 52 parameters and helps to reduce uncertainty in the determination of descriptive parameters, 53parameter interdependency and respective contributions to damage. This study aims to (1) 54 enable the estimation of damage probability for a certain hazard intensity, and (2) obtain data 67show that 90% of these tests have a success rate of more than 67%. Probabilities (at building 882011; Thouret et al., 2013Thouret et al., , 2014, and apparent locally high vulnerability of buildings and 89 critical infrastructure in Arequipa, are major motivations for this study. 90Risk in the context of disaster risk management is commonly defined as a potential loss for a 91 given probability function (Crichton, 1999; Kaplan and Garrick, 1981). In the standard 92 conceptual framework, risk is the product of hazard, vulnerability and exposure (Cardona, 93 2004; Carreno et al., 2006). While the hazard is generally described by its severity, e.g. 94inundation height for a given return return period, exposure relates to the number and value of 95 elements potentially affected (Hiete and Merz, 2009). Many different definitions, concepts and 96 methods to systemize vulnerability exist in the current literature (Birkmann, 2006; Cutter, 2003; 97 Wisner et al., 2004; Thywissen, 2006; IPCC, 2007; Bründl et al., 2009). In this study we follow 98 the definition for physical vulnerability proposed by Glade (2003) and Villagran de Leon (2006) 99 as the predisposition of an element or system to be affected or susceptible to damage as the 100 result of the natural hazard's impact. Vulnerability assessment for hydro-geomorphic hazards conducted to study and record structural damage following a hazard event, these data are then 112 generally correlated to the process intensity, frequently derived from deposition height or 113 inundation height, in order to develop empirical fragility curves (Fuchs et al., 2007a,b; Holub 114 and Fuchs, 2008 133Flash floods are common in semi-arid areas, such as Arequipa, and can, despite their 134 infrequent nature, have a devastating effect in both geomorphological and human terms 135 (Gaume et al., 2009; Jonkman and Vrijling, 2008;Martínez Ibarra, 2012). The occurrence of 136 flash floods is highly variable, both spatially and temporally, most occurring as the result of 137 localized intense storms (Graf, 1988;Reid and Frostick, 1992; Hooke and Mant, 2000 , 2007a,b; Holub and Fuchs, 2008). 160Several recent studies (Martelli, 2011;Santoni, 2011; Ettinger et al., 2014a,b; Thouret et al., 161 2013 Thouret et al., 161 , 2014 192On 8...

Spatial Assessment of Urban Flood Susceptibility Using Data Mining and Geographic Information System (GIS) Tools

“…Various data-mining approaches have been used for decades to predict and assess flood occurrence [11,12]. In general, soft computing or statistical data-mining techniques have recently been used, such as the decision-tree based model [13][14][15], artificial neural network (ANN) based model [16][17][18], support-vector machine [19][20][21] or the logistic regression (LR) model [22,23]. Proactively, a basic statistical model, frequency ratio (FR), is used to observe trends between flood-related factors and flood events [24][25][26][27].…”

Quantifying lahar damage using numerical modelling

“…Lahars, defined as gravity-driven flows containing a mixture of volcanic sediment and water (Vallance and Iverson, 2015), have caused severe damage to infrastructure and buildings (e.g. de Bélizal et al, 2013;Pierson et 25 al., 2013;Ettinger et al, 2015;Jenkins et al, 2015) in addition to being responsible for a large proportion of volcanic fatalities (Auker et al, 2013). Assessing the extent of potential lahar damage can be difficult due to the complexity of flow behaviour, uncertainty in the number of elements exposed to lahars (e.g.…”

“…Here we focus on quantifying and examining the relative importance of hazard, exposure and vulnerability in determining lahar induced building damage. changes during the event which alters exposure and often rely on a-priori assumptions of building strength and vulnerability (Ettinger et al, 2015). Pre-event assessments are affected by the lack of reliable hazard intensity measures (van Westen et al, 2006;Ettinger et al, 2015), differences in spatial and temporal scales, uncertainty 40 surrounding site-specific lahar triggers (Di Baldassarre and Montanari, 2009) and a lack of structural information on building stock (Ettinger et al, 2015).…”

“…changes during the event which alters exposure and often rely on a-priori assumptions of building strength and vulnerability (Ettinger et al, 2015). Pre-event assessments are affected by the lack of reliable hazard intensity measures (van Westen et al, 2006;Ettinger et al, 2015), differences in spatial and temporal scales, uncertainty 40 surrounding site-specific lahar triggers (Di Baldassarre and Montanari, 2009) and a lack of structural information on building stock (Ettinger et al, 2015). These issues are reflected in the relative lack of studies on hazard impact in urban areas (Jenkins et al, 2015) and often results in a reliance on expert judgement to develop vulnerability models for lahars and flash floods (Ettinger et al, 2015).…”

“…The physical vulnerability of buildings, defined as the susceptibly of a building to damage with respect to the 45 hazard (Künzler et al, 2012), is a function of building characteristics such as size, shape, age, construction materials, structural integrity, maintenance and build quality (Martelli, 2011;Künzler et al, 2012;Ettinger et al, 2015). Information on these building properties is often lacking and hard to collect on a large scale.…”