Using scanning technology to support ecologically sustainable road planning

For the past two years, SMEC’s specialists in ecology and urban development have been collaborating with the Victorian Department of Transport to guide...

For the past two years, SMEC’s specialists in ecology and urban development have been collaborating with the Victorian Department of Transport to guide future planning for two arterial roads east of Bendigo. Our role is to help the Department of Transport improve capacity and safety on these arterial links, in accordance with the principles of ecologically sustainable development, avoidance and minimisation of impacts to native vegetation, and relevant state and Commonwealth legislation.

After collecting preliminary ecological data within the road reserves, our teams undertook targeted fauna surveys for threatened species and the Flora and Fauna Guarantee (FFG) Act-listed Temperate Woodland Bird Community, and then began detailed vegetation surveys.

It was important to accurately survey the location, species and Diameter at Breast Height (DBH) of all trees within the road reserves, to understand potential impacts to vegetation as early as possible. The challenge was how to collect the large amount of data required in a cost-effective and timely way. The traditional method was to employ a team of field surveyors and ecologists who would require up to three months to complete the work. However, this project had approximately 15,000 trees that needed to be considered during project design and mapped over summer, meaning weeks of fieldwork that would present not only time challenges but potential Occupational Health and Safety (OHS) issues with hot weather.

Our ecologists leveraged the expertise of our survey team in Melbourne to develop an innovative solution. The survey team recommended an alternative methodology using advanced laser scanning techniques to obtain detailed information on trees during the project’s concept design phase.

Mobile Laser Scanning (MLS) was used to measure the position of tree trunks and canopies. MLS scanning collects geospatial data from a mobile vehicle, such as a car, fitted with LiDAR, cameras and other remote sensors. By using MLS, we were able to quickly and efficiently capture field data, reducing the time required from months to days.

“We can use the raw 3D point cloud information that is outputted by the MLS, along with the latest computer aided drafting software, to extract tree locations more quickly than what was possible only a few years ago,” said Rohan Bakker, Manager of SMEC’s Survey team. “This provides our client with a highly accurate deliverables in several different electronic formats that are compatible in systems such as GIS, AutoCAD DWG and Microstation DGN, at a lower cost than what was achievable in the past.”

This approach has provided the Department of Transport with detailed data on trees, complementing other SMEC studies on native vegetation and threatened fauna. The resulting data forms a comprehensive database on environmental values in the road reserves that will enable our client and partners to make more informed decisions on road planning and design. It has also delivered financial benefits to the client as a result of a reduction in labour costs from up to months of fieldwork to two weeks.