Bangkok is turning to artificial intelligence (AI) and LiDAR mapping to strengthen its fragile, largely uncounted urban forest – promising safer streets, lower maintenance costs, and a high-tech shield against deadly air pollution.
Traditionally, assessing tree inventories and their conditions has been time-consuming and costly. Maintenance has required visiting every tree individually before determining whether intervention was needed. The Smart Tree Inventory (STI) changes this through a car-mounted mobile laser scanner that combines 3D scanning and panoramic imaging to rapidly capture data on thousands of trees.
Peter Sassi, Vice President of Greehill Asia-Pacific Pte, a Singapore-based tech firm specialising in mapping and managing urban green assets, explained that the STI analyses the data using AI. ‘This information is prepared for experts so that they can focus their attention on the trees that actually need help and concentrate limited maintenance resources where they matter most,’ said Sassi during his talk ‘Urban Forests for the Future: Global Lessons and Local Actions for Bangkok.’
Sassi likened the technology to medical diagnostics. ‘You can imagine this as a whole-city MRI machine,’ he said. ‘Currently, you either go to one tree and treat it – which is very expensive – or you treat an entire district and end up over-treating it.’
Measurable Impact: Safer Streets and Cost Savings
The introduction of AI-driven monitoring translates immediately into improved public safety and lower costs. Globally, STI has been shown to identify dangerous trees before they fall, reducing the risk of injury and property damage. Communities using the system report safety improvements of over 80%.
At the same time, STI enables cities to shift from blanket maintenance to precision care. By targeting trees flagged with serious lean angles, dieback, or structural defects, municipalities can save up to 30% on maintenance budgets. ‘If the bad things already happened, it’s a lot of cost to clean up afterwards,’ Sassi said. ‘But if you do some pruning before, it’s much easier.’
Local Crisis: Air Pollution and the Uncounted Forest
Bangkok’s move to digital mapping comes amid growing concern over the city’s worsening air pollution, particularly PM2.5 particulate matter. Trees remain one of Bangkok’s most effective natural defences – but managing them has been impossible without accurate data.
Assoc Prof Dr Chairat Treesubsuntorn, Head of the Remediation Laboratory at King Mongkut’s University of Technology Thonburi, underscored the scale of the problem. ‘In Bangkok we face too much pollution such as particulate matter during the winters,’ he said. ‘Imagine if you have to walk to every tree to check height, diameter, and leaf count – it’s impossible.’
Of Bangkok’s estimated three million trees, fewer than 1% have been electronically documented. This massive data gap prevents the city from making informed decisions about species selection, maintenance, and pollution mitigation. ‘We have very high diversity of tree species,’ Dr Chairat added, ‘and we cannot use research from other countries easily – we need local data.’
Bridging the Gap Through Collaboration
Effective implementation depends on collaboration between the private sector, academia, and civic groups. Santi Opaspakornkij of the Big Trees Foundation noted that while the governor’s initiative has successfully planted over a million new trees, sustaining them requires long-term management.
He pointed out that many existing trees are ‘big, old, but not very strong’ due to root damage caused by later urban development. To overcome these challenges, partnerships and technology are essential. ‘When international visitors or experts say the same thing that Thai organisations have been saying for years, people tend to listen more,’ he added.
The STI serves as the unifying tool for these collaborations, offering objective data that can transform Bangkok’s urban forest into a measurable, actively managed city asset.
A Shift to a Data-Driven City
The Smart Tree Inventory represents more than a maintenance upgrade – it marks a shift toward making Bangkok a data-driven, resilient city. By digitising its green infrastructure, Bangkok is transforming neglected urban trees into a critical component of its environmental strategy, improving air quality, enhancing safety, and safeguarding public health.
This cross-sector collaboration establishes a foundation of scientific data that will guide the planting and management of the next generation of urban trees – ensuring that Bangkok’s green canopy not only grows, but thrives for decades to come.