Urban resilience and disaster preventive planning. Manage the preparation to optimize the response in the historical towns
In the aftermath of a disaster, time is a precious resource, but extremely limited. The decision-makers and planners have to face, with the other responsible entities, the task of assisting the affected communities, recovering the local economies and protecting the natural and built environment, toward reducing the future risk. To address this issue, several governments have begun preparing for the recovery ahead. This approach is most commonly defined "Pre-Disaster Recovery Planning". The importance of concretely initiate prevention activities during the pre-disaster phase finds pragmatic feedback in the development of preventive plans. These allow to structure an effective scheduling to be used in the first stage of the Disaster Life Cycle (DLC) and perform the basic function for the realization of re-al Reconstruction Plans (PdR) in case of need. The drafting timing of the PdR and the necessary material for their predisposition are specifically analyzed through the investigation S.De.P.R.A. (Descriptive Study of the Abruzzo Reconstruction Plans), in addition to criticalities and potentialities for the protection of built heritage in historic towns. The proposed model of Preparation Plan (PdP) is composed of analyzes and documents useful for a municipality to schedule the knowledge and prevention activities on its territory, identified as key elements of the analyzed PdR. The paper discusses in detail a deepening investigation on the built environment elements for the plan: the analyzes concerning the historical evolution of the urban fabric, the constructive characteristics and the seismic vulnerability assessments on both urban and aggregate scale. We expose the results of the proposed model and the crisis preparation strategies on two case studies of small to medium sized historic centers (Lazio and Umbria), integrating vulnerability analysis, con-structive features and aggregates evolutionary phases with a urban/systemic approach to reach the definition of priorities for action in the historic city.