Non-Invasive subsurface analysis.
Ground penetrating radar (GPR) has been adopted by arborists to provide insight into what is happening at a subsurface level, with the non-invasive technology revealing the span of objects such as tree roots, and allowing for the informed planning of projects.
As explained by Arbor Operations owner Peter Mumford, while GPR is an established technology in the arboriculture sector, the uptake by industry at a local level has been relatively slow, with the cost of the equipment being a primary barrier.
However, the benefits provided can be significant, with Peter pointing to GPR’s ability to prevent root damage in undertaking new construction projects, and to identify potential issues with existing infrastructure.
Ground penetrating radar: applications for new and existing infrastructure Peter told AAF that one of the primary uses for GPR is to allow arborists to conduct non-invasive analysis of subsurface conditions ahead of breaking ground on new projects, allowing for appropriate planning and preparation.
This information, presented in a 2D or 3D format, can be harnessed to determine what needs to be avoided when undertaking landscaping or building works.
“Roots grow on the path of least resistance – when encountering compacted soil or a harder medium in the soil they duck and weave,” Peter explained. “If you use GPR, you can identify where they’re located, and at what depth, and map out where they are.
“It means little to no impact to tree roots, and it ensures that the larger root mass isn’t damaged, because if you damage the root system, a tree’s vitality will be impacted through loss of root mass.”
Meanwhile, when it comes to a range of existing infrastructure, GPR can be used to identify potential issues with root growth, including the impact of growth on underground assets such as pipes and building foundations.
Peter advised that GPR can be deployed to provide insight into what is happening at a subsurface level for a range of infrastructure.
“If it’s impacting existing infrastructure, the other function is to identify the root locations in proximity to the infrastructure,” he said.
“It might be a roadway, it might be a curb, it might be a building, and GPR can identify the cause, eliminating the guesswork.”
Combining Arboricultural And Geophysical Knowledge
Peter told AAF that there are a range of different software package products available in the market.
“The software is usually tied to the different GPR manufacturers’ devices, and they all have their little idiosyncrasies,” he said. “We use Object Mapper, which is MALA’s product.”
Peter explained that it is not as easy as simply creating a 3D image, with a substantial amount of work being undertaken following deployment of the GPR machine, and pointed to the necessity of combining biological and geophysical knowledge.
“There’s quite a bit of post-processing work that goes into identifying tree root locations,” he commented. “It requires an element of understanding of tree biology, which is really important, and also a geophysical understanding.
“It’s a product offering which brings together a combined scientific and engineered solution to the work that we do.”