Context

The Isle of Wight, an island located off the Southern coast of England is known for its coastal landscapes, cliffs, and landslide-prone areas, especially along its southern part.

In December 2023, the upper section of Leeson Road was closed following one of the largest landslides ever recorded on the South Coast of England. The event saw 16 hectares (approximately 14 million cubic metres of land) displaced, posing a significant threat to local infrastructure and residents.

The instability was attributed to a combination of factors, including toe erosion, where the base of the cliff that provided critical support to the land mass had been worn away, and extreme weather, as heavy winter rainfall led to elevated groundwater levels that further destabilized the geology.

Given the scale of the movement and the continued environmental risks, a sophisticated, remote monitoring solution was required to help ensure safety and guide long-term maintenance.

Solution

SOCOTEC UK deployed a high-resolution wireless monitoring system to track ground movement and provide early warnings in a hazardous coastal environment where manual surveying was risky and difficult. The system included strategically placed devices across the landslide zone to ensure comprehensive coverage.

• The first element, multiple high-precision Worldsensing GNSS Meters, captured absolute 3D displacement with sub-centimeter accuracy, ensuring continuous monitoring even during poor weather. 
• Tiltmeters complemented this by detecting subtle slope changes and automatically increasing sampling during critical events to capture detailed movement data.
• The deployment was finalized with the installation of Piconode with rain gauge and 7 data loggers with varying inputs -Vibrating Wire, Analog and Digital- connected to extensometers, in-place inclinometers to a depth of 120m, and piezometer sensors.

Data from all sensors was transmitted via long-range LoRaWAN to a centralized cloud platform, allowing engineers to monitor trends remotely, set automated alerts, and integrate the information seamlessly into SOCOTEC’s software (Blue Trust Monitoring) for a unified view of the landslide’s behavior.

Benefits

The implementation of the remote monitoring system brought significant improvements to managing the Leeson Road site. Early warning capabilities enhanced safety by detecting critical movements before they could escalate while the remote sensors reduced the need for manual on-site inspections, improving operational efficiency and minimizing risks to personnel. This enabled residents to return to their properties and allowed the opening of a high-dependency transport link connecting two main towns on the south of the island.

Continuous, real-time data streams increased confidence in decision-making when assessing the stability of the landslip area. Additionally, the scalable deployment ensured long-term data availability, enabling more effective allocation of maintenance resources.

The successful deployment on the Isle of Wight highlights the value of digital innovation in proactive asset management. By integrating GNSS with tilt detection, SOCOTEC UK and Worldsensing provided a robust framework for safeguarding infrastructure and managing the risks associated with dynamic coastal environments.

Advantages

• Cost-effectiveness: Scalable deployment ensures ongoing data availability for proactive maintenance and easy addition of more monitoring parameters.
• Robust monitoring framework: Integrates GNSS, tilt detection, pore water pressure measurement, deep rotational movement and extension of tension cracks in order to provide a reliable system for managing dynamic coastal environments.
• Proactive asset management: Supports infrastructure resilience by enabling data-driven interventions before failures occur.