Some remarks on a rational and interdisciplinary approach to the savety and conservation of historical centres in Abruzzo Region

In the last decade, Central Italy was struck by very long earthquake sequences and suffered heavy damage caused by events characterised by high magnitude. This is the case of large in area in the Lazio, Marche and Umbria regions hit by the sequence started in the summer 2016 and the Abruzzo hit also by the L'Aquila earthquake occurred on April 6th, 2009. All these events impacted on a very complex territory characterised by a few highly urbanised areas and small towns fragmented in many minor municipalities and small villages. In such a context, the primary matrix of the built environment is the historical one; each settlement is generally associated to relevant architectural and landscape features founded on consolidated history of the area. From such a perspective, the problem of the conservation and of the resilience of minor historical centres and settlements in the Central Italy is becoming a key issue at International level due to the strong interrelation between cultural, social, technical and financial aspects. This is the background of this paper that moves from the assumption that lessons learned from the implementation of measures able to recover the built heritage, and more generally the territory in the L'Aquila area following the 2009 earthquake can be useful to refine some interdisciplinary problems like the knowledge of the built environment in view of performance assessment and the definition of monitoring protocols aimed at preserving the construction during its ordinary life, but also in the event of earthquake sequences. In order to avoid a too general statement of the problem and also to perform a validation of the envisaged interdisciplinary approach to the problem, the attention of this contribution is focused on some historical and construction peculiarities that can be found in the Abruzzo region, namely the fortified sites. The region is rich in castles, towers and fortified enclosures that have undergone numerous transformations over time. Some of these have developed creating the magnificent villages that, with their fortified residences, define the territory, others have been abandoned becoming suggestive ruins of which, still today, can be appreciated the main features, namely the ancient city walls interrupted by several defensive towers. It is a topic that appears worth investigating due the specific nature of the construction, but also because in many cases these typologies represent the early core of many small villages distributed in the area. Historical and architectural features of the construction of interest are analysed by means of the traditional methods adopted in the context of restoration processes; historical, architectural, constructive and structural knowledge are however reviewed and discussed in the light of the interventions eventually designed and/or made on selected structures after the 2009 earthquake. The results of a kind of SWOT analysis are presented in order to provide a contribution in the development of advanced tools for protection of historical heritage from environmental hazards