Using InSAR to Combat Erosion and Landslides
Isle of Wight, United Kingdom
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Perform Permanent Scatterers (PS) & Small Baseline Subset (SBAS) Differential Interferometric Synthetic Aperture Radar (DInSAR) analysis to measure displacements.
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Identify movement trends in the coastline in terms of differential settlement in millimetres.
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Pinpoint areas of concern (accelerating movements) in order to better deploy remediation measures and environmental defences.
Want to read more about how Finite Element Analysis and geospatial data can aid in coastline fortification efforts? Read more.
Highlights
The Isle of Wight's soft coastal cliffs are becoming increasingly vulnerable to erosion due to ongoing exposure to the sea. As erosion accelerates, so does the risk of landslides, raising serious concerns about the safety of infrastructure situated on or near the cliffs.
Increasing Coastal Erosion and Lack of Historical Data
With the situation rapidly worsening, there was no time to rely on traditional in-situ measurements, which were not available for the preceding years. The absence of systematic historical data made it difficult to assess the current risk levels effectively, and immediate action was required to understand and mitigate the growing threat of landslides and subsidence.
InSAR for Historical and Current Ground Movement Analysis
To address the challenge, Geofem deployed Interferometric Synthetic Aperture Radar (InSAR) technology to analyse historical and recent satellite data. By assessing time series data, InSAR could pinpoint areas where ground movement was accelerating, providing an early warning system for regions most at risk of landslides. By combining InSAR results with geotechnical data—such as the properties of the soil and rock—stakeholders gained an objective and comprehensive understanding of how the coastal situation was evolving.
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The Benefits: Proactive Coastal Monitoring and Cost-Effective Solutions
InSAR's ability to analyse retrospective satellite data offered a significant advantage by allowing the study of past trends in displacement, providing greater certainty in the analysis. Early identification of affected areas enabled mitigation efforts to begin before landslide events occurred, allowing for proactive maintenance that was far more cost-effective than reactive solutions. Furthermore, the analysis covered a much wider area at a fraction of the cost of in-situ monitoring, making it a scalable solution for large-scale coastal monitoring.
Safeguarding Coastal Infrastructure
This case demonstrates the power of satellite-based InSAR technology in coastal environments, providing accurate, cost-efficient monitoring over extensive areas. As the Isle of Wight’s coastline continues to erode, early detection and proactive measures can help safeguard critical infrastructure and reduce the economic impact of landslides.
