We present a case study of a Structural Health Monitoring (SHM) hybrid system based on Brillouin Distributed Fiber Optic Sensors (D-FOS), Vibrating Wire (VW) extensometers and temperature probes for an existing historical water penstock bridge positioned in a mountain valley in Valle d’Aosta Region, Northwestern Italy. We assessed Brillouin D-FOS performances for this kind of infrastructure, characterized by a complex structural layout and located in a harsh environment. A comparison with the more traditional strain monitoring technology offered by VW strain gauges was performed. The D-FOS strain cable has been bonded to the concrete members using a polyurethane-base adhesive, ensuring a rigid strain transfer. The raw data from all sensors are interpolated on a unique general timestamp with hourly resolution. Strain data from D-FOS and VW strain gauges are then corrected from temperature effects and compared. Considering the inherent differences between the two monitoring technologies, results show a good overall matching between strain time series collected by D-FOS and VW sensors. Brillouin D-FOS proves to be a good solution in terms of performance and economic investment for SHM systems on complex infrastructures such as hydropower plants, which involve extensive geometry combined with the need for detailed and continuous strain monitoring.

Flood damage assessment is an essential asset in flood risk management, and the literature brings several models, most based on damage curves. This kind of approach is essential and well established but not suitable for being applied in the immediate aftermaths of a flood. Herein, a new application of a zero-order model for the Po-Venetian plain area, which covers more than 20% of the Italian territory, is conceived and implemented. At first, a calibration of the model with damage data coming from past events in the region is carried out, showing that the calibration is site-specific. In particular, it is shown how the exponent in the power-law form of the model is the same as obtained in a previous work on another territory, while the intercept, defined as specific damage, varies. Then the algorithm is applied to the area affected during the flood that hit the Emilia-Romagna region (Northern Italy), in December 2020, for validation. Knowledge of the affected area comes from the quick assessment procedure commonly performed by the National Fire Corps in any significant flood, employing low-altitude all-weather helicopter GPS surveys. The paper shows that combining the model with such a rapid mapping technique leads to a near real-time estimation of damages in the aftermath of floods. The results are aimed at obtaining a first approximation figure. The estimation error shows this figure to be not far from those obtained with much more detailed approaches, requiring a much longer time for their setting. For that reason, the model results can contribute, among other things, by directing the immediate post-emergency management operations and promptly allocating financial resources for recovery.

Quantitative data on observed flood ground effects are precious information to assess current risk levels and to improve our capability to forecast future flood damage, with the final aim of defining effective prevention policies and checking their success. This paper presents the first collection and analysis of flood damage claims produced in Italy in the past 7 years since a homogeneous national procedure for damage recognition became available. The database currently contains more than 70,000 claims referring to significant events and shows good homogeneity on the intensity of the related phenomena. We then propose an empirical model, based on observed data, to allow for a quick estimation of direct damage to private assets (i.e., residential buildings), based only on the knowledge of the perimeter of the flooded area. Single model calibration was performed at the multi-regional scale, focused on southern Italy. Model validation shows encouraging performances, considering the considerable natural uncertainty that characterizes this type of estimate. The procedure is of great interest when there is a need to evaluate, however roughly, flood damage in the immediacy of the event to assess the extent of the flood effects and to plan support actions for the affected communities.

The problem of levee embankment control during high flows is crucial for flood risk management in floodplains. Levee defense lines are often hundreds of kilometers long and surveys during emergencies are not easy tasks. For these reasons, levees monitored with in situ sensors and a suitable Information Technology (IT) real-time data communication and integration infrastructure, so-called “smart levees”, are gaining increasing interest as a crucial protection technology in floodplains. The paper presents the conceptualization of a prototype of a levee smart revetment, based on the integration of an optical fiber (OF) cable into a steel double-twisted wire mesh. In this paper the feasibility of this kind of revetment is firstly assessed. The flow pattern of overtopping water on the embankment is discussed, thus producing a raw estimation of the shear stress acting on the revetment in the field. A sample case is then analyzed in both numerical and laboratory tests. For this purpose, a numerical Finite Element Model (FEM) to describe the mechanical behavior of a double-twisted wire mesh when loaded along its own plane is presented. Numerical results indicate that the related strain, relatively low as compared to the steel wire yield stress, can be fully detected by the optical fiber continuous Brillouin sensor. This has been validated by the experimental activity performed and a digital twin of the prototype of the smart revetment, suitable for virtually testing the product under any load and constraint conditions and tailoring the production process, has been created.

Smart levees represent a revolution in the field of embankment monitoring and safety during flood events. A smart levee, intended as the native (or “from scratch”) integration of an engineering structure with sensors and connection systems, provides detailed information on its past, current and future conditions Viz. integrity stress/strain conditions, maintenance state. This gives decision support to the figures in charge for maintenance and surveillance of the embankments, increasing efficiency and, particularly, the degree of protection from flood events. Sensor information can also be mashed up with other information, such as water stage, rainfall, soil wetness offering an useful integrated view of the river context.  We present here first results of a research project concerning the conceptualization of a sensing anti-erosion revetment for embankments, through the integration of a double-twisted steel wire mesh with an optic fiber cable. The fiber is woven  into the double-twisted sections and is capable to detect the nearly continuous deformation of the meshes caused by stresses exerted in its plane. The sensor sensitivity is enough to record deformation due to (small) shear stresses exerted by eventual overtopping flows, though it can bear (and report) huge deformations typical of quite higher stresses up to thousands of microstrain.  Several cycles of experiments, jointly with numerical modelling, clearly show the feasibility of such a product line, also showing a good linearity of the smart revetment behavior.