Mitigation of urban vulnerability through a spatial multicriteria approach

Seismic risk management is generally carried out through strategies aiming to reduce building seismic vulnerability, working on structural features and not considering that the concept of vulnerability can be adopted also referring to the whole urban system. In order to adopt a different approach, considering not only building and infrastructure vulnerability and according to the goal of managing seismic risk reducing urban vulnerability, it is strategic to identify in peace time (before disastrous events) which elements, which activities, which functions of a city have prior importance after the event, to guarantee a rapid response and the reestablishment of normal conditions: this means identifying the resilient city. This study aims to define a methodological approach to identify the resilient city, adopting spatial multicriteria techniques and establishing resilient system identification considering functional, social, morpholo¬gical, geological and dimensional characteristics of the considered urban system. In particular, some tests, considering a first set of criteria including accessibility, closeness to urban centres and main facilities, closeness to hydrographical networks, slope, map of seismic hazard, areas at high hydro-geological risk and seismic vulnerability of buildings, have been carried out on a town in Basilicata Region (southern Italy), mainly composed of an old part located on a hilltop, a modern part in the valley and a lot of rural settlements. Multicriteria analysis has been led adopting an additive rule, based on a simple additive weighting method.