The City of Ryde is using machine learning to analyse tree canopy cover across its local government area, helping it to plan for population and business park growth.
Speaking at the recent Navig8 conference hosted by ASX-listed aerial imaging provider Nearmap, Ryde’s head of land information Lindsay Mason said the council needed more data on its green spaces to enhance planning, investment and livability.
The local government area, located 12km northwest from Sydney’s CBD, is home to Australia’s fourth largest economy thanks in part to the Macquarie Park Innovation District and its 180 multinational companies, Mason said.
It also has 120,000 residents - projected to grow by 30 percent over the next 15 years - who make use of Ryde’s 207 parks on a daily basis and value the blend of natural landscape and proximity to work.
“We’ve just had a community and strategic plan [written], and the community has told us what they want. One of the goals of [council] is to preserve and protect both urban and natural areas,” Mason said.
“One of the challenges we’ve got at the moment is that council has detailed information about the 20,000-odd trees that [we] manage in streets and parks, and we have a 10-year history of Nearmap aerial photography, but that doesn’t give us a complete picture of the local government area in terms of tree canopy cover.”
Tree canopy cover is a useful indicator for the distribution of green spaces, which can be used to reduce urban heat islands through shade and evaporation.
The City needed a reliable and easily repeatable way to measure canopy cover regularly.
“We had a look at a number of different solutions to do that," Mason said.
“Something like LiDAR is incredibly expensive and takes a long time to do, so we then started to look at aerial photography and had a conversation with the Nearmap team about what was possible.”
Working with Nearmap’s AI team, Mason and his team were able to create a canopy cover dataset from aerial imagery that could then be added as a layer to the council’s geographic information system (GIS), which is available to all members of staff.
“This enables staff from right across the organisation to utilise and take into account tree canopy cover as they’re doing their day-to-day tasks - so things like planning future infrastructure or assessing a development application or even doing strategic planning or day-to-day management of parks and natural areas now can take into account tree canopy cover," Mason said.
The aerial images from which the canopy data is obtained are accurate to 30cm, Mason added, meaning council staff and the public could be confident in the data quality.
It can also be updated every year (to ensure the same amount of seasonal growth between years, images are obtained in the height of summer), or more frequently to locate and assess the damage from storms.
“One of the things we will be able to do in the future, if we have a storm event, is that we’ll be able to contact Nearmap and get this analysis run again, and we can very quickly assess the impact the storm may have had on the tree canopy cover across the local government area, so we can be much more agile than we were able to do in the past," Mason said.
“Certainly in NSW recently, we’ve had in the past 12 months a couple of major storms and the bushfires as well, and how that impacts tree canopy cover is certainly something we are using this data to do more analysis on.”
