The UK GEO-Instruments team are working with their client for the Environment Agency to monitor Noise, Vibration and Air Quality during coastal defence improvement works at Pevensey and Eastbourne in East Sussex.
The coastal defence scheme involves extensive beach regeneration and maintenance works covering 15 kilometres of the Sussex coastline from Pevensey Bay to Eastbourne.
The scheme is being delivered by the Environment Agency in partnership with local councils and comprises multiple phases over the next decade.
The current phase of works involves moving 5,000m3 of shingle and installing timber to improve wave screens along the Pevensey frontage.
The shingle, an important part of the sea defences, naturally moves and accumulates at Eastbourne due to longshore drift. Large trucks are being used to relocate the shingle four miles northeast along the coast to Pevensey beach. A bulldozer is then used to distribute the material across the beach.
The operation requires up to 96 trips a day so has the potential to generate significant, noise, dust and vibration.
A versatile monitoring solution was required to measure the potential impact the works might have on local residents and businesses.
Key monitoring sites include beachfront properties and Martello towers — historic, circular coastal forts built to defend against Napoleonic France.
Owing to the widespread work area and day-to-day migration of the work it was most efficient to design a single monitoring setup that could be easily moved where needed, depending on the location of the works.
GEO-Instruments supplied a modular battery-powered monitoring setup comprised of a noise sensor, a vibration sensor and an air quality station assembled on a movable tripod to enable setup in regularly changing locations.
The instrumentation used includes a Sigicom INFRA S50 sound level meter and an INFRA V12 triaxial geophone connected to a shared data logger and a Turnkey Osiris air monitoring device.
These sensors were chosen for their reliability in automatically collecting and transmitting accurate monitoring data with minimal need for on-site maintenance or expertise. This system allows site teams to simply place and power-on the setup and the beginning of each workday.
At certain stages the noise/vibration and air quality setups are separated to meet changing monitoring requirements.
The sensors send collected data to GEO-Instruments’ QuickView software for automated visualisation and reporting.
Using QuickView to manage the project monitoring data means exceedance alerts, graphs and daily and weekly reports can all be distributed automatically, with configurations that can be set up or modified remotely.
A key consideration when interpreting recorded data is keeping detailed records of sensor locations at the time measurements are taken. On most projects, this is relatively straightforward, as monitoring points generally remain fixed.
However, in this application, maintaining efficient records relating sensor locations to the collected data presented a challenge.
To address this issue the QuickView team developed a new feature that allowed site teams to easily view and update sensor location records.
The software automatically updates the sensor locations on a map based on input dates and locations, a project journal is updated, and graphs are annotated to mark changes in location and allow easy differentiation of data.
Basic coordinates or what3words locations can be used for convenience and clarity of communication.
The versatile site setup and intuitive software tools allow for a cost-efficient monitoring scheme, employing the minimum amount of instrumentation to cover a large site area.
The current phase of coastal maintenance works is ongoing and is expected to run until 2027.
Read more about GEO-Instruments’ environmental monitoring projects.