Self-Supervised Tree-level Biomass Estimation in Urban Environments From Airborne LiDAR and Optical Observations
Summary
A novel framework quantifies crown-level above-ground biomass (AGB) for an 810~km$^2$ urban landscape in Ontario, Canada, utilizing 2018 and 2023 leaf-off airborne LiDAR (8--10~pulses~m$^{-2}$) and near-infrared RGB orthophotography (0.16--0.20~m). This system employs a dual-stream cross-attention network, trained with rule-based pseudo-labels, to semantically mark buildings, needleleaf, and deciduous trees, achieving 0.86 precision, 0.83 recall, and 0.84 Dice scores on independent tiles. Multiscale watershed segmentation delineates crowns, with AGB estimated via a crown area--height power-law proxy calibrated to species-specific allometry (Lambert et al., 2005) for 21,921 inventory trees. AGB prediction yielded R^2=0.609 with inventory geometry and R^2=0.570 operationally, highlighting crown delineation as the primary uncertainty. Aggregated 30m estimates show 1.73~Tg AGB in 2018 and 1.81~Tg in 2023, representing a 39~Gg~C net gain over five years. The framework operates without manual annotation, using standard provincial data, and generates a public bitemporal crown-level AGB database.
Key takeaway
For urban planners and environmental scientists seeking scalable, accurate urban tree biomass quantification, this framework offers a robust, annotation-free solution. You can utilize standard provincial LiDAR and optical data to generate bitemporal crown-level AGB maps, enabling precise carbon stock assessments and monitoring. Focus on refining crown delineation techniques to further reduce estimation uncertainty.
Key insights
Self-supervised deep learning combined with LiDAR and orthophotography enables accurate, scalable urban tree biomass estimation.
Principles
- Pseudo-labeling can train semantic segmentation networks effectively.
- Crown delineation is a key uncertainty in AGB estimation.
- Bitemporal data reveals urban carbon stock changes.
Method
A dual-stream cross-attention network, trained on rule-based pseudo-labels, performs semantic segmentation. Multiscale watershed segmentation delineates crowns, followed by AGB estimation using a calibrated crown area-height power-law proxy.
In practice
- Use LiDAR and orthophotography for urban tree mapping.
- Implement pseudo-labeling to avoid manual annotation.
- Monitor urban carbon sequestration with bitemporal AGB maps.
Topics
- Self-Supervised Learning
- Airborne LiDAR
- Urban Biomass Estimation
- Semantic Segmentation
- Crown Delineation
- Carbon Sequestration
Best for: AI Scientist, Research Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by Computer Vision and Pattern Recognition.