The importance of the lessons learnt from past disasters for risk assessment

Abstract

Within the Mountain Risk Project, the study area of the Consortium of Municipalities of Valtellina di Tirano (Italian Alps), has been selected in order to collect both kinds of knowledge, scientific and local, and to correlate it to the levels of preparedness and perceived risk of the population. A quantitative survey was performed using a comprehensive questionnaire to evaluate several aspects related to the response capacity. In the meantime available historical information about natural hazards (landslides and floods) and consequent disasters have been collected and organized in a comprehensive database designed with the aim of using such data for hazard estimation and definition of risk scenarios as a basis for Civil Protection planning and emergency management purposes. The results show that even if: (a) there have been multiple damaging events in the past, as show in the database, and (b) most of the population is aware of the existence of past events, the levels of preparedness are low and the population has low levels of perceived risk, and what is more, population neglect the existence of recurrent small to medium events (which are the most common according to the database) and remember mostly the large events, as the one of (Alexander 1988). This means that in the study are a gap between the occurred disasters and the possible lessons to be learnt still exist and an effective method to share and disseminate knowledge is missing. Additionally, when the information is collected and available, it is necessary to communicate it to the local authorities so they can adapt the existent governance framework not only to the physical situation but also to the perception, awareness and risk knowledge of the population. According to Wanczura (2006), the aim of providing people with information is to broaden their view of hazards and risks, because only those hazards and risks that are known and understood can be mitigated. Lessons learnt from local knowledge of previous events are not sufficient to manage disasters effectively since, even if this knowledge helps reduce risk, it is sometimes inadequate to cope with new disasters. Similarly, scientific knowledge, technology and data are not enough to assure an effective risk reduction since they lack of a holistic picture and deeper analysis of the local vulnerability context. What is fundamental is the ability to combine them and to put them into practice being this the real reflex of learning from previous experiences. Combining both types of knowledge is crucial to reduce uncertainty, thus proving more precise information for the decision-making, key element of any risk governance process.