Geomatic Techniques for the Mitigation of Hydrogeological Risk: The Modeling of Three Watercourses in Southern Italy

Climate change in recent decades has made exceptional rainfall increasingly frequent, with the consequent risk of flooding of watercourses. Streams and rivers characterized by short flow times are subject to rapid and impressive floods; for this reason, the modeling of their beds is of fundamental importance for the execution of hydraulic calculations capable of predicting the flow rates and identifying the points where floods may occur. In the context of studies conducted on three watercourses in Calabria (Italy), different survey and restitution techniques were used (aerial Lidar, terrestrial laser scanner, GNSS, Photogrammetry). By integrating these methodologies, multi-resolution models were obtained, which constitute the basis of the hydraulic calculations performed. The representations of models and effects that hydraulic calculations have predicted in the event of exceptional rainfall (flow, speed, flooded areas and critical points in the banks) constitute useful tools for designing appropriate defense works and preparing evacuation plans in the event of an alarm, with the aim of mitigating hydrogeological risk.