Fig. 4. Concert area, 5:00 pm: visualization of the alarm spreading in the target area for one simulation with the enabling radius equal to 100 m. The
enabling area is colored in blue. Red circles represent nodes within 1 km of the alarm center, orange circles represents nodes within 2 km of the alarm
center and green ones represent infected nodes. The radius of each circle is 50 m. (For interpretation of the references to colour in this figure legend, the
reader is referred to the web version of this article.)
Moreover, as the population’s spatial distribution and mobility change over time (as shown, for instance, in [12]), we
consider two different starting times: (i) 5:00 pm; (ii) 9:00 pm. The first time corresponds to when people started gathering
around the river, and the second time is in the middle of the concert and right before the fireworks.