Advanced sensing and IoT for monitoring climatic risks and natural hazards at underwater and coastal cultural heritage

As climate change progresses, shifting weather events are expected to become more severe 1, posing a significant threat to heritage sites but also to connected communities. The monitoring of climatic risks at coastal and underwater heritage sites is considered of significant importance to enhance understanding of degradation processes but it constitutes a resource-intensive and intricate process. Frequently, data collection from devices requires the coordination of expeditions for sensor retrieval and manual data acquisition. The monitoring area's spatial extent is limited due to the utilization of stationary sensors. Another challenge lies in the integration of both subaquatic and terrestrial parameters into an advanced monitoring solution that provides an unobstructed assessment of the hazards encompassing the heritage area. The development of multiple low-cost sensors endowed with Internet of Things (IoT) capabilities, can facilitate real-time monitoring and positioning for both subaquatic and terrestrial data collection of environmental parameters that amplify the deterioration of heritage assets. To address subaquatic data acquisition, an IoT Conductivity Depth Temperature (CDT) device has been designed to measure salinity and temperature characteristics with a dual role of a wearable sensor for divers and a static sensor affixed near the seabed. To streamline data transmission beyond aquatic environments, the device is engineered to transmit data when situated outside the water. The second subaquatic sensor developed serves the purpose of crowdsourcing and designed to be attached to vessels from local communities, enabling real-time data collection on salinity, temperature, and chlorophyll concentration. Both subaquatic devices integrate Inertial Measurement Unit (IMU), Narrowband Internet of Things (NB-IoT), and Global Navigation Satellite System (GNSS) technologies within their design. The proposed coastal monitoring solution incorporates a weather station with the capacity to measure and transmit real-time data on diverse weather parameters, encompassing temperature, humidity, rain volume, wind speed, UV index, and light intensity. The fourth device integrates strain gauges and accelerometers, offering valuable data for both static and dynamic monitoring. This enables the assessment of vibration levels and provides information on the evolution of cracks and tilts within the monitored site. To optimize energy efficiency, all four devices have been engineered with low power consumption capabilities. Furthermore, devices located outside the water are equipped with solar panels to ensure complete energy autonomy. In conclusion, the development of multiple low-cost sensors with IoT capabilities demonstrates a commitment to overcoming the financial and logistical complexities of data collection. By incorporating advanced technologies such as IMU, NB-IoT, and GNSS into subaquatic devices, we enhance the precision and versatility of real-time monitoring and positioning. By seamlessly integrating technological innovation with practical considerations, we aim to provide a comprehensive and efficient means of safeguarding these invaluable cultural and environmental treasures. Acknowledgement: This research has been funded by European Unions Horizon Europe research and innovation programme under THETIDA project (Grant Agreement No 101095253). References: 1 Michalis, P.; Tarantino, A.; Tachtatzis, C.; Judd, M.D. (2015). Wireless monitoring of scour and re-deposited sediment evolution at bridge foundations based on soil electromagnetic properties. Smart Mater. Struct. 2015, 24, 125029.