The North West Strategic Regional Coastal Monitoring Programme was established in 2008 to coordinate the collection of coastal monitoring data for the north west coast of England.
It is part of the National Network of Strategic Regional Coastal Monitoring Programmes that cover the coastline of England and Wales. Sefton Council is the lead authority for the north west programme and is responsible for the delivery of the project on behalf of the other English coastal authorities in the North West and North Wales Coastal Group.
About the Project
The monitoring programme aims to provide data and information to coastal managers to enable the sustainable management of their coastlines. The distance the programme needed to monitor was a total of 750 miles of beaches, sand dunes, saltmarshes, cliffs, and hard defences with the overall goal of the project being to capture near shore and onshore data across the north west coastline. This data would allow the councils to better understand the coastal processes on a local and cell wide basis and thus make better informed decisions.
Challenges
A section of the 22 miles of sand dunes between Liverpool and Southport, known as the Formby coastline
Flood risk and coastal erosion are serious issues for authorities in north west England. The councils take these risks very seriously, having suffered severe coastal flooding a number of times in the early 2010’s. In addition, parts of north west are influenced by shallow groundwater and the flood risk from surface water and main rivers. These factors plus the coastal geomorphology makes the north west area sensitive to the effects of climate change.
To continuously monitor such a large stretch of coastline takes a huge amount of time and effort for the council and its contractors, making time management one of the biggest challenges in a project of this scale. Coastal erosion is a constant natural process, and to capture the amount of data the councils required, the time constraints were critical.
"We had seen the benefits of laser scanning with the C10, but, when scanning miles of hard and soft defences, it is very time consuming. We needed a solution that combined speed, robustness and portability.” Andrew Martin - Senior Officer, Flood and Coastal Erosion Risk Management, Sefton Council
Implementation
To overcome the time issue the north west coastal monitoring programme compared their existing monitoring equipment (The Leica C10, CS20 and Viva GS16), and looked at which other solutions on the market could provide the necessary requirements for their project.
In the past, they had utilised a GNSS receiver mounted onto a quad to drive up and down the beach taking levels. They purchased a Leica C10 in 2011 to scan the dunes, using a GPS to orientate the scan each time they set it up. In addition to the C10 and GNSS receiver, the council also purchased an UAV (DJI Phantom) for aerial scanning.
Initial interest was also expressed in the new GS18i; however, the one-minute bursts would not give the council the required speed to complete the surveys needed. Thus the coastal monitoring programme purchased the Pegasus:Backpack solution, the award-winning wearable reality capture platform that collects data indoors, outdoors and underground.
The highly ergonomic design of the Pegasus:Backpack combines five cameras offering a fully calibrated 360 degrees view, plus two LiDAR profilers with an ultra-light carbon fibre chassis. It enables extensive and efficient indoor or outdoor documentation at the highest level of accuracy. The Pegasus:Backpack is designed to act a sensor platform with our standard external trigger and sync port outputs.
This unique mobile mapping solution is designed for rapid and regular reality capture. It is completely portable, enabling the coastal monitoring programme to be able to quickly complete the surveying and monitoring work required without the need to haul heavy equipment up and down the sand dunes.
Full training was provided to members of staff from the coastal monitoring programme from Leica Geosystems, allowing them to quickly get to grips with the system and begin their work in earnest.
Benefits
The Pegasus:Backpack made progressive professional documentation a reality for the coastal monitoring programme. It synchronised imagery and point cloud data, therefore assuring a complete documentation of the sand dunes for full life cycle management. By using SLAM (Simultaneous Localisation and Mapping) technology and a high precision IMU, it ensured the coastal monitoring programme achieved accurate positioning with GNSS outages.
The point cloud classification toll segments the LiDAR data into roads, pavements, buildings, vegetation, and street furniture classes, all automatically. This new feature, available in the latest release of Pegasus:Manager software and valid for all Mobile Mapping Solutions (Pegasus:Swift, Pegasus:Two Ultimate and Pegasus:Backpack), allows users to exclude all undesirable data with no need of manual cleaning process.
“In this particular case, it allows the coastal monitoring programme to exclude all coastal vegetation from their datasets. This is possible due to Machine Learning and Deep Learning Artificial Intelligence algorithms developed within Hexagon Geosystems." Antonio Mendes – Mobile Mapping Business Development & Sales, Leica Geosystems UK
The solution helped the coastal monitoring programme to make better and faster decisions in emergency situations due to access to more accurate data. Evacuation plans and route mapping benefit from clear and detailed images and point clouds that alert authorities to any changes.
“The Pegasus stood out as it is able to capture data at speed, we trialled it on the back of a quad bike, and it does not have the weather constraints or licensing issues associated with a UAV. Best of all, it is fairly simple to use and process the data. The system has enabled us to perform more surveys and we plan on expanding this, before Pegasus we would do 3 may be 4 laser scans a year. Since April 2021 we have done 5 and have more planned. Arguably we have increased productivity.” Andrew Martin - Senior Officer, Flood and Coastal Erosion Risk Management, Sefton Council
A view to the future
With the successful implementation of the Pegasus:Backpack solution, the coastal monitoring programme are now planning on doing baseline scans of the hard coastal defences across the North West, with the goal of providing accurate information to the coastal authorities to allow them to ensure these defences are up to the required standard to protect not only the environment, but local residents from the risks of flooding and erosion.
This blog was adapted from Hexagon (2022) Protecting the coastlines of the North West British Isles - North West Strategic Regional Coastline.