NEW APPROACH FOR DEFINING THE SCHOOL SYSTEM EXPOSURE IN THE CONTEXT OF THE CIVIL PROTECTION PLANS

The aim of paper is therefore to deepen the exposure within the definition of risk. In particular, the approach introduces and quantifies indicators of different types, linked to characteristic aspects of a place and able to know the variation of the level of exposure to risk with time. Dynamic scenarios are defined temporally to plan mitigation actions in: peace time (thus reducing the potential damaging effects of an event) and emergency (actions of coordination and rescues management). The scenarios thenrefore analyze the entire municipal territory this because “the involvement of the proximity context of the infrastructure opens up tempting opportunity to test strategies for urban regeneration that raising the quality of the adjacent spaces may also offer opportunities to mobilize private capital available to the perspective of sustainable urban development and socially cohesive” (Di Girolamo, 2016). A good indicator system is useful for helping to efficiently planning and allocates resources as well as monitoring the emergency situations. The approach considers also the determination of a global exposure index, which brings together the individual indicators. This global index also allows defining a hierarchy of priorities for the interventions to be implemented. These scenarios, which consider the introduction of specific indicators to the definition of exposure, will be the basis for new Civil Protection Plans. This model has been realized thanks to the interdisciplinary of urban planning with mathematic. Among the different settlement systems, the paper examines the school system. In order to carry out a qualitative-quantitative analysis, each indicator has been associated with exposure levels that must be checked and adapted to each analysed case. The indicators proposed for defining exposure of the school system and the corresponding range of values are five. They have been defined thanks to interviews with experts.

The first two indicators (which take into account the time factor) are:

INDICATOR 1 - AGE: takes into account the age of the student population present within the considered educational institution and consequently their awareness of the danger and autonomy in the pre-emergency and pre-emergency phases;

INDICATOR 2 - REFERENCE: refers to the maximum number of students present at the peak hour. This value is taken as a reference for the next calculation.

The evaluation of these first two indicators is through the definition of a database that needs to be constantly updated (Database 1, Fig. 1). For the structures analysed, this database must be compiled with the number of presence during precise intervals of time. In the case of the school system here investigated, the number of students and operators -teachers, janitors ..., in the different levels of school education, also varies substantially during the daily span. For monitor over time the presence of the population exposed to risk is therefore considered important discretize the day in intervals of half an hour. In addition, to examine the different times of presences / lessons (which is not said to be the same every day, think for example on Saturdays and Sundays) and closing days is essential to consider the presences during the days of the week, in the different months of the year.

Fig. 1 Database 1 for the collection of data on the presences and the determination of 1 (age) and 2 (reference) indicators

The subsequent indicators provided by the methodological approach refer to the time that the emergency vehicles would employ to reach the exposed structure (calculated on the shortest path), they are:

INDICATOR 3 - PATHS: attributed on the basis of the number of paths that allow the main relief providers (Croce Rossa, Fire fighters, Civil Protection Department, Hospital ...) to reach the school in a short time.

It is important to underline that 4 school-rescue organization links were taken into account, but in any other application this value could be changed according to the available services;

INDICATOR 4 - LOCALISATION: linked to the location of the considered structure respect to the morphology and the centrality of the same in the urban system;

INDICATOR 5 - ALTERNATIVE/ACCESSIBILITY: assumes values equal to 1, in the case in which there are no alternative paths for reaching the school and assumes a value of 0, when there are more roads leading to the school in question.

For the calculation of afore mentioned times is important to consider any building sites, or possible slow-down or blocking situations, that the calamitous event could generate. For the quantification and calculation of these

indicators, a study on the location of the school structure analyzed is required and a second database containing all the useful information was created (DATABASE 2, Fig. 2).

Fig 2 Database 2 referring to the localisation and distances between rescue organizations and schools for the calculation of the 3 (paths),4 (localisation) and 5 (alternative) indicators

The approach therefore provides, a first phase of the compilation of the elaborated databases (1 and 2) with the quantification, for each exposed considered, of the 5 indicators. Having identified the most critical time intervals from DATABASE 1, starting from indicator 2, a new indicator is calculated, called reference indicator 2, assigned to the maximum number of presences (Fig. 3). Subsequently, the global exposure index is introduced, which considers the combination of the five indicators defined above (Fig. 3). This is an algebraic algorithm that combines in a weighted way the described indicators providing a final value between 0 and 1.

Fig 3 Temporal exposure calculation

The global index considers the sum of the specific global indexes for the different intervals, allowing a depth analysis of the school structure under study. The methodological approach also includes the mapping of the various indicators, so as to identify the situations most at risk and therefore, for them, propose solutions that reduce exposure. These mappings are fundamental to subsequently evaluate the global index and thus have a total situation mapping. The exposures scenarios obtain are no longer static but dynamic over time and taking into account the characteristics of the places of the considered exposures. The methodological approach developed should be considered within the new Municipal Civil Protection Plans. For a better management in the Plan, a graphical interface to be used is proposed. In this specific case, through the use of Matlab, an interface for the school system has been defined (Fig. 4).

Fig.4 School system interface

By inserting the data characterizing the school into the two databases (1 and 2), the defined instrument (interface) directly provides the value of the global exposure index. This global index allowing to have immediately a daily view of the variation of exposure at risk (Fig. 5).