Accelerating Wildfire Hazard Mapping Across Canada with an AI Surrogate Modelling Framework
Organizations: Mila: Quebec AI Institute · Natural Resources Canada - Canadian Forest Services
Abstract
Canada's increasing wildfire activity requires frequent national hazard mapping to guide proactive mitigation, including fuel management, land-use planning, infrastructure protection, and evacuation routing. However, process-based wildfire simulation frameworks (e.g., BurnP3 and BurnP3+) rely on computationally intensive Monte Carlo simulations to model burn probability, fire intensity, and rate of spread. These workflows can take days to weeks to process a single regional modelling unit. To overcome these computational bottlenecks, we present three contributions developed through collaboration between AI researchers and wildfire modelling experts: (a) a standardized framework for training, fine-tuning, and evaluating AI surrogate models against process-based wildfire simulators; (b) a multi-task deep learning surrogate trained on national-scale data to emulate burn probability, mean fire intensity, and mean rate of spread at a fraction of the computational cost (seconds); and (c) domain-specific metrics and counterfactual evaluation protocols to probe out-of-distribution generalization. Integrating geospatial data (fuel, terrain, ignition likelihood) and regional weather, our model approximates BurnP3+ simulation outputs, achieving strong performance across agreement, rank-correlation, error, and spatial-overlap metrics. It preserves downstream hazard classifications and produces physically plausible responses to expert-informed counterfactual interventions. Furthermore, we demonstrate zero-shot transfer to a separate regional BurnP3+ study and show that lightweight fine-tuning can substantially improve regional calibration and predictive agreement. On a representative region, the surrogate achieves 806-fold end-to-end CPU acceleration and uses 13% of BurnP3+'s host memory, facilitating rapid scenario analysis.
Figures & tables
| Target | Model | Normalized MAE | Normalized Bias | Spearman | CCC | AUC IoU Top-10% | AUC IoU Full |
|---|---|---|---|---|---|---|---|
| BP | Mean Baseline | ||||||
| XGBoost | |||||||
| U-Net Spatial | |||||||
| + Weather | |||||||
| + Weather + Fire Size | |||||||
| FI | Mean Baseline |
| BP3+ Baseline: 38.9 h (140,040 s) | Memory: 100.8 GB | 32 CPUs | |||
| Hardware Setup | Inference (s) | Total E2E (s) | RAM + Device |
| GPU (L40S) | 8 + 29 GB (37%) | ||
| MacBook (MPS) | 30 GB (30%) | ||
| CPU (4 Cores) | 13 GB (13%) | ||
| Hardware Setup | Speed-up Factor vs. BurnP3+ | ||
| GPU (L40S) | |||
| Metric | Value |
|---|---|
| Exact 13-Class Accuracy | |
| Within-1 Bin Accuracy | |
| Within-2 Bin Accuracy | |
| High Hazard ( ) IoU |
| Intervention | Model | |||
|---|---|---|---|---|
| C2 M1 | BurnP3+ | |||
| C2 M1 | AI Surrogate | |||
| Burned area D2 | BurnP3+ | |||
| Burned area D2 | AI Surrogate | |||
| QC BC weather | AI Surrogate | |||
| Climate-adjusted spread duration | AI Surrogate |
| Target | Model | Normalized MAE | Normalized Bias | Spearman | CCC | AUC IoU Top-10% | AUC IoU Full |
|---|---|---|---|---|---|---|---|
| Scenario A | |||||||
| BP | U-Net (Base) | ||||||
| + Recalibration | |||||||
| + Zone Alignment | |||||||
| FI | U-Net (Base) | ||||||
| + Recalibration | |||||||
Appendix figures & tables14 assets
Supplementary material from the paper’s appendix.
Appendix
| ID | Name | Description | fbp_code | FuelType | SeasonState |
|---|---|---|---|---|---|
| 1 | Spruce-Lichen Woodland | C-1 | 1 | C-1 | direct |
| 2 | Boreal Spruce | C-2 | 2 | C-2 | direct |
| 3 | Mature Jack or Lodgepole Pine | C-3 | 3 | C-3 | direct |
| 4 | Immature Jack or Lodgepole Pine | C-4 | 4 | C-4 | direct |
| 5 | Red and White Pine | C-5 | 5 | C-5 | direct |
| 6 | Ponderosa Pine - Douglas-Fir | C-7 | 7 | C-7 | direct |
| Feature Name | Source | Dimension | Processing |
| Input: Spatial | |||
| Fuel | Forest Fire Behaviour Prediction (FBP) System ( Forestry Canada Fire Danger Group 1992 ) | Neural network compression of 18-D iROS curves | |
| Ignition | ( Erni et al. 2024 ) | Cause-aggregated layers with mean imputation | |
| Elevation | Digital Elevation Model ( Natural Resources Canada 2024 ) | Min-max normalization (train-split statistics) | |
| Terrain Derivatives | Derived from Elevation | Slope via ; Aspect via unit vector ( ) | |
| Input: Tabular (Weather & Environmental Context) | |||
| Target | Model | Normalized MAE | Normalized Bias | Spearman | CCC | AUC IoU Top-10% | AUC IoU Full |
|---|---|---|---|---|---|---|---|
| Patch-Level Evaluation | |||||||
| BP | Mean baseline | ||||||
| XGBoost | |||||||
| U-Net Spatial | |||||||
| + Weather | |||||||
| + Weather + Fire Size | |||||||
| Target | Hexel | Normalized MAE | Normalized Bias | Spearman | CCC | AUC IoU Top-10% | AUC IoU Full |
|---|---|---|---|---|---|---|---|
| BP | Region 01 | ||||||
| Region 12 | |||||||
| Region 16 | |||||||
| Region 39 | |||||||
| Region 49 | |||||||
| FI | Region 01 |
| Hazard class | interval |
|---|---|
| 1 | |
| 2 | |
| 3 | |
| 4 | |
| 5 | |
| 6 |
| Target | Model | Normalized MAE | Normalized Bias | Spearman | CCC | AUC IoU Top-10% | AUC IoU Full |
|---|---|---|---|---|---|---|---|
| BP | U-Net Spatial | ||||||
| + Weather (Spatial) | |||||||
| + Weather (Tabular) | |||||||
| FI | U-Net Spatial | ||||||
| + Weather (Spatial) | |||||||
| + Weather (Tabular) |
| Target | Model | Normalized MAE | Normalized Bias | Spearman | CCC | AUC IoU Top-10% | AUC IoU Full |
|---|---|---|---|---|---|---|---|
| BP | Single-task | ||||||
| Multi-task | |||||||
| FI | Single-task | ||||||
| Multi-task | |||||||
| ROS | Single-task | ||||||
| Multi-task |
| Target | Model | Normalized MAE | Normalized Bias | Spearman | CCC | AUC IoU Top-10% | AUC IoU Full |
|---|---|---|---|---|---|---|---|
| Scenario A | |||||||
| BP | U-Net (Base) | ||||||
| + Recalibration | |||||||
| + Zone Alignment | |||||||
| FI | U-Net (Base) | ||||||
| + Recalibration | |||||||
Surrogate Modeling
Surrogate modeling builds faster or more interpretable approximations of expensive simulations and black-box models.
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