Skip to content

Fire Model Scaling

This workflow tests whether classical local fire-spread mechanisms produce:

P proportional to A^sigma

where P is exterior fire perimeter and A is burned area.

Implemented Tier

Current Tier-1 implementations:

  • exact expanding ellipse benchmark
  • Huygens wavelet front-propagation emulator
  • Eulerian level-set front-propagation emulator
  • cellular-neighbor spread emulator

Actual-software status is recorded in outputs/tables/actual_model_status.csv and logs under outputs/logs/.

Current actual-software status:

  • ELMFIRE: real tutorial 01 constant-wind case completed from https://github.com/lautenberger/elmfire. Raw outputs are copied to outputs/raw/elmfire_constant_wind/.
  • Cell2Fire: native C++ build attempted from https://github.com/cell2fire/Cell2Fire; build failed because Boost headers were unavailable.

Run

PYTHONPATH=src python -m unittest discover -s tests
python scripts/run_fire_model_scaling.py

Outputs

  • outputs/metrics/fire_model_scaling_metrics.csv
  • outputs/tables/scaling_fits.csv
  • outputs/tables/fixed_exponent_scores.csv
  • outputs/tables/local_slopes.csv
  • outputs/figures/figure2_loglog_perimeter_area.png
  • outputs/figures/figure3_sigma_by_model.png
  • outputs/figures/presentation_fire_model_geometry.png

Interpretation Guardrail

A local front-propagation equation does not guarantee sigma = 1/2 under all heterogeneous, anisotropic, fragmented, or time-varying conditions. sigma = 1/2 is expected when growth is approximately self-similar or shape-preserving. The experiment tests whether each implementation retains that geometry or generates increasing boundary complexity.

The current Tier-1 fitted-scaling results should be read as mechanism-emulator results. The real ELMFIRE tutorial output exists, but it has not yet been wired into the same perimeter-area measurement workflow. Do not describe the Tier-1 fits as actual ELMFIRE, WRF-SFIRE, FARSITE, FlamMap, or Cell2Fire outputs.