“…They are strongly influenced by the site stratigraphy (Tsai and Chiang 2013), while their complex processes hindered the development of reliable hydrological models for the prediction of these thresholds. In fact, low-intensity prolonged rainfalls can sometimes be more dangerous than short and intense ones (Doglioni et al 2011;Galeandro et al 2013), showing how the singularity of an event is often more critical than its exceptionality.…”