UEA coastal erosion project will test new tech’s predictive powers

DiSTANS – the Distributed Strain, Temperature and Acoustic Sensing Suite project is being led by the University of East Anglia's School of Environmental Sciences, in collaboration with the British Geological Survey, as well as North Norfolk District Council and Trimingham Parish Council.

Funding by a capital grant of £0.46 million from the National Environment Research Council has enabled the purchase of advanced fibre optic ground sensing equipment to monitor erosion on a stretch of the north Norfolk coast between Sidestrand and Trimingham. 

Jessica Johnson, Associate Professor in Solid Earth Geophysics at UEA, said: “We are proud to be working with Trimingham Parish Council and North Norfolk District Council, the people who are most affected by coastal erosion, on this pilot project. If successful, the project can easily be scaled up to monitor greater stretches of coastline continuously, which will aid decision-makers in planning and mitigating risk.” 

Researchers plan to pinpoint weak areas of cliff most likely to fall and identify the cause of subsidence. But it will also provide an opportunity to test the effectiveness of the new technology being used in place of more traditional methods. 

The novel Distributed Sensing (DS) technology imitates radar systems with signal generators sending light along the optical fibres up to 100 kHz. A proportion of the light reflects off impurities in the fibre and returns to source. 

Variation in the pulse travel are measured for their timing and angle, which are then analysed to reveal the cause, such as ground movement or temperature change.  
 
While Norfolk and areas of East Anglia are notably vulnerable to erosion, the problem is widespread in the UK with more than a quarter (28%) of the English and Welsh coastline suffering erosion rates of 10 cm/year or more, says the project team. 

The technology has also provided the opportunity for cross collaboration between UEA’s environmental science and computer science departments, in order to best exploit and interrogate the data captured.

Computing PhD students Harry Whitelam and Dom Seager will employ techniques including machine learning in order to interpret evidence.

Said Seagar: “UEA’s commitment to collaboration, both internally and externally, means Computing Science students here have opportunities to work beyond traditional boundaries and in impactful contexts, which is something that has always appealed to us.” 

“Using Distributed Sensing we will be able to gather a wealth of data, allowing us to conduct a thorough investigation and hopefully reveal useful insights into these natural processes. This information can then inform the latter stages of the project, so we can hone in on the impactful causes and discover how they impact the scale and frequency of coastal activity.” 

The DiSTANS Project will examine:

• DS use to characterise coastal erosion events and causes
• DS ability monitor subsurface fluid and stresses
• How recession rate varies over time and space in the context of climate change and degrading defences 
• Which areas display increased subsurface cracking and/or slumping 
• Whether cliff collapses be forecasted 

 Pic: Crispin Jones