Residents of Brienz are undergoing emergency evacuation due to potential rockfall risks from nearby mountains. Advanced radar and monitoring systems are being employed to assess the situation. Similar technologies are utilized across the Swiss Alps to track unstable slopes. Companies like Terradata specialize in long-term monitoring, including satellite tracking of cable cars on permafrost. While effective, these systems face challenges like distinguishing false alarms from wildlife activity. Rapid responses based on monitoring data are crucial for community safety.
Evacuation of Brienz: A Community on Alert
Residents of Brienz are currently facing an emergency evacuation due to concerns that debris from the mountainside could pose a significant threat to their village. Experts remain uncertain about the extent of the danger, as it is unclear whether the loose rock will come to a stop before reaching the settlement or if there will be any movement at all.
Advanced Monitoring Systems in Action
To keep a close eye on the precarious slope, two radar systems from the monitoring company Geopraevent, along with various other measuring devices, are in operation. The rockfall radar, which functions similarly to police Doppler radar for speed detection, can quickly identify when rock fragments begin to fall. Complementing this is an interferometric radar that precisely measures the rock’s movement across the entire slope with millimeter accuracy.
While Brienz is currently under scrutiny, it’s important to note that this situation is not unique. Across the Swiss Alps, numerous locations are equipped with monitoring instruments to track unstable slopes and rock formations that threaten communities. The mountains are interconnected with a network of thousands of cameras and sensors, all aimed at detecting potential hazards.
Various companies in Switzerland are dedicated to this form of monitoring, and many have implemented responsive alarm systems designed to safeguard lives and critical transportation routes from geological shifts. Their clients typically include cantonal and municipal authorities, the Federal Office for Roads, Swiss Federal Railways, engineering firms, and cable car operators.
Philippe Gsponer, from the cantonal office for natural hazards in Upper Valais, emphasizes the importance of specialized companies for more complex monitoring tasks. These companies often possess the advanced technology and expertise necessary for effective monitoring. One such firm, Terradata, is also active in Brienz, deploying a range of measurement instruments. According to Mario Studer, a managing director at Terradata, different organizations have honed their focus on specific technologies, with Terradata specializing in long-term monitoring systems.
One striking application of these warning systems involves monitoring cable cars situated on permafrost. Terradata utilizes satellite navigation to track the precise shifts of cable car stations and masts, with approximately fifty measuring stations currently operational across Switzerland. For instance, a cable car near Riederalp is under constant observation due to the glacier’s retreat, with data sent hourly to assess any shifts that may occur.
In addition to surface monitoring, underground measurements are also critical. Terradata employs inclinometers to gauge landslide movements, using probes inserted into boreholes to measure the angles of shifting rock. This technology has proven essential at the Riedberg Tunnel construction site, where geologists have gained crucial insights into landslide dynamics.
Newer measurement technologies are emerging, such as autonomous drones designed for environmental monitoring. While this innovative approach shows promise, regulatory approvals from the Federal Office of Civil Aviation are still pending, which prevents operational use of these drones for now. Presently, drone monitoring must be conducted under the supervision of qualified specialists.
Warning systems, while effective, require time for data processing, unlike alarm systems that must react to events within seconds. The aforementioned rockfall radar serves as a perfect example of this distinction, as it can be integrated with other technologies, like seismic sensors, to enhance its effectiveness. In areas prone to rockfall, such as the Gumpisch region near Lake Lucerne, this combination allows for quick decision-making regarding potential threats.
Nevertheless, alarm systems face challenges, particularly concerning false alarms. Wildlife movements can confuse radar readings, making it difficult to distinguish between animal activity and actual rockfall. However, when combined with seismic sensors, these systems can accurately determine when to trigger an alarm based on specific signals associated with rock movements.
Depending on the client, an alarm can initiate various responses, from activating traffic lights to sending alerts to construction site personnel. In many scenarios, implementing an alarm system may not be feasible due to costs. However, even with long-term monitoring, unexpected developments can necessitate urgent measures. This was the case for a monitoring project in Muotatal, overseen by Mario Betschart from Innet.
During a visit to the Canton of Schwyz’s Department of Natural Hazards, he learned of a rock in motion at the end of Muotatal. In collaboration with local authorities, they initiated a test operation involving advanced laser measurement technology, aimed at tracking the rock’s movement. Within a week, the data indicated significant acceleration, prompting immediate action.
Betschart swiftly communicated the findings, leading to increased scrutiny of the area beneath the rock. Shortly thereafter, the rock, which had been monitored for movement, broke free, burying a hiking trail and pasture, and capturing the attention of hikers who witnessed the event.
The rapid shift from monitoring to real-time response illustrates the critical nature of these technologies in safeguarding communities from natural hazards.