Coastal erosion along a stretch of Northumberland coastline has been monitored by an Amble-based drone manufacturer.
QuestUAV began observing the strip between Alnmouth and Cresswell in 2008 and has studied the impacts of major storms over the past few years.
Within this area, the company has primarily focused its coastal-monitoring programme on the seven-mile-long Druridge Bay section.
Now, QuestUAV has published the findings of its research, which shows areas of erosion, especially following a tidal surge last month.
And the company, which is based at Coquet Enterprise Park and employs 20 people, believes the study shows the benefits of using drones – a type of unmanned aerial vehicle – for reliable and accurate coastal monitoring.
Kerstin Traut, QuestUAV’s geo-spatial expert and UAV operator, wrote the case study.
She said: “Time-series of QuestUAV’s drone-based maps reveal that Druridge Bay is going through seasons of alternately material removal and deposition. It would be a relief to say that yearly deposition balances erosion rates.
“However, the long-term analysis shows that there is more loss than gain of material along Druridge Bay.
“Even non-experts can clearly see the land loss in the drone-based time-series (see image, right).
“Floods have removed dune turfs and even moved big rock structures.”
The company says that since 2008, the local coast has been hit by ‘two exceptionally strong flood events – one in November 2013 and in January this year’.
Immediately after the latest storm, crews flew the area to assess the impact of the floods on the basis of the long-term image series taken by the team.
The workflow involved a correlation of information from historic sources, satellite imagery and 3D-modelling.
The concentration of the survey was on the less protected dune land, especially to see how much property owners have lost from erosion.
One of the areas that the company focused on was at a dune property at Low Hauxley, see picture below.
The image shows the area before September 2016 and after the latest flood in January.
Reflecting on the study in the Low Hauxley area, Kerstin said: “The latest flood changed the frontline of the dunes by one-to-two metres.
“Rocks and previous coastal erosion measures became exposed. Large volumes of sand and grass were removed and slumps occurred within hours of high tides.
“Our calculations show that approximately 850 tonnes of dune and dunefoot was lost along an 80-metre stretch of coastline and the high-water mark receded by up to 2.2 metres at the most critical point.
“The expected slumps that will happen as a result of erosion at the toe are expected to carry a further 300-tonne loss within 12 months.
“To see the long-term development of the coastline, we also included a flight from January 2013 in our analysis.
“The storm event in November 2013 had comparable impact as the latest flood.
“Fortunately, sand, stones and organic matter deposits along existing structures and the coastline recovers over the years.
“As long as the big storms do not increase in frequency, the hope is the local coast will not particularly be endangered by coastal erosion. Monitoring is essential though.”
And this is where Kerstin and her colleagues believe that drones can play a vital part in helping to protect the coastline.
She said: “Drones will continue to take an ever-increasing role in the monitoring and assessment of coastal erosion and assist in effective decision making for local planners and environmental bodies.
“They are a great asset for monitoring the stability of a coastline and for carrying out a rapid initial survey after a storm event.”
Work is already being done to protect the county’s coastline, both now and for future generations.
A spokeswoman for Northumberland County Council said: “We have worked with North Tyneside Council to produce a shoreline management plan for the length of the coast from the Scottish Border to the River Tyne.
“This provides the policy framework for managing the risks from coastal erosion and sea flooding along the coast in a sustainable manner over the next 20, 50 and 100 years.
“It provides an assessment of the risks to people and the developed, historic and natural environment associated with coastal erosion and sea flooding.
“It also recommends actions including ensuring that where appropriate the existing defences and natural coastal features are regularly inspected and maintained.
“Last year, for example, the council used its powers to help provide coastal protection measures in Boulmer, where a new defence was constructed to protect 26 properties from erosion, funded by the Government.”