Volumetric surveys to enable future planning in remote areas

A methodological approach to obtain all necessary data 

A bathymetric survey of both lochs and a topographical survey of the surrounding shorelines were required, including three cross-sections on the River Bran joining the two lochs. We undertook the bathymetric survey using an echo sounder linked with a GPS receiver to obtain the bed levels. The boat covered the area with a series of long and cross profiles from which a dense regular grid (10 m x 2 m) of levels was generated, and a bed surface model created. 

The bed surface model up to the water line was combined with the topographic survey data to support the calculation of the volumetric data required. 

To allow the customer to determine floor risk models within the loch and provide various volumetric calculations, we carried out three separate volume calculations on Loch Achanalt based on the 110.50 m, 110.60 m and 110.70 m contours and ten calculations on Loch A’Chuilinn at 0.1 m intervals from 110.60 m to 111.50 m. 

We derived a depth storage curve from the gathered data to demonstrate storage in million cubic meters stored below a specified water level, in meters above Ordnance datum. 

All personnel and equipment were mobilised from UTEC’s base in Livingston, Scotland. 

Innovations in action

By introducing the use of UAV LIDAR, we  

• minimised the time on-site and reduced the number of field crews. Customarily, topographic data would have been captured by “boots on the ground” at a significantly higher cost and longer time scale.
• reduced the environmental footprint of the operations as there was no requirement for people walking across the site, preventing disruption of ground-nesting birds. 

The result 

Our flexible approach to survey methodologies allowed us to gather all necessary data, despite the weakness of satellite signals in these remote areas. Both land and air capture methods reduced the safety and environmental risks as well as cost.