A New Approach to Modeling Post-Earthquake Shelter Demand: Integrating Social Vulnerability in Systemic Seismic Vulnerability Analysis

A new approach for modeling demand for emergency shelter and housing caused by earthquake damage which integrates social vulnerability into the modelling approaches is presented. The focus here is to obtain shelter demand as a non-linear consequence of building habitability and social vulnerability of the affected population rather than building damage states alone. The shelter model simulates households' decision-making and considers physical, socio-economic, climatic and spatial factors in addition to modelled building damage states. Social vulnerability conditions are integrated into the framework using Multicriteria Decision Analysis whereby factors including tolerance to loss of utilities (water, gas or electricity) given climatic conditions and a number of socio-economic characteristics influencing the desirability of the building occupants to seek public shelter are accounted for. To operationalize the shelter model, appropriate indicators from the EU Urban Audit Database have been selected using principal component analysis combined with expert judgment. Vulnerability factors deduced from the EU Urban Audit have been validated by applying the model using data from the M 6.3 earthquake that struck L' Aquila, Italy in April 2009.