Catastrophe resilience related to urban network shape: preliminary analysis

People living in a city represent the most important agents of the urban system. In fact, people organize bits of the city, while organizing their own lives, hence directly influencing much of the city structure, from both a human point of view and a topological one. Such a self-organizing process reflects on both safety and life quality of citizens and efficiency of city services. As a result, in order to better manage a city one should know its inhabitants' behaviour and its topological configuration too. An ambitious goal that can be pursued in the sense of complex networks theory approach, studying the urban centre as a hybrid social-physical network made by both human and physical components (HSPN)[1]. In this study different topological structures and geometric shapes of cities are investigated, focusing on the efficiency of cities themselves, and their resilience. Moreover, due to the current increasing risk of natural and human-induced disaster threatening local communities, urban societies are suffering a gradual reduction of their actual and potential resilience, as their ability to cope and withstand with external events. To this purpose, seismic events are simulated for each investigated urban geometry, referring to the most common shapes existing worldwide. A novel systemic measure of the expected damage state is here defined, which allows for a vectorial measure of the city efficiency in its entirety. Urban resilience is assessed as an integral measure, before, during and after an extreme event occurs. Thence, a recovery strategy is hypothesized and the efficiency of the HSPN network and the resilience of the city are then evaluated and compared in a time-discrete analysis.