Comparison with Other Wildfire Simulation Tools =============================================== .. note:: **Note on naming**: WRF-Fire and WRF-SFIRE refer to the same coupled fire–atmosphere system built on the WRF mesoscale model. The official package name is WRF-SFIRE; "WRF-Fire" is a common shorthand used in the community. .. warning:: **Disclaimer**: The comparisons below are based on publicly available documentation and peer-reviewed literature as of 2025. Capabilities of third-party tools may have evolved or may differ across versions. Consult the official references linked in the `Tool Documentation References`_ section for authoritative and up-to-date information. This table is intended for high-level orientation only and should not be taken as an exhaustive or definitive characterisation of any tool. Capability Summary ------------------ Tools are grouped into three columns to keep the table compact: * **Group A — Operational fire behavior tools**: FARSITE · FlamMap · BehavePlus * **Group B — Physics-based LES/CFD tools**: QUIC-Fire (QUIC-URB) · FIRETEC * **Group C — Coupled fire–atmosphere NWP**: WRF-Fire (WRF-SFIRE) .. list-table:: :header-rows: 1 :widths: 22 28 20 15 15 * - Capability - **Wildfire-AMR** (this solver) - **Group A** — FARSITE / FlamMap / BehavePlus - **Group B** — QUIC-Fire / FIRETEC - **Group C** — WRF-Fire (WRF-SFIRE) * - **Surface spread model** - Rothermel (1972), Balbi (2009), and 5 others (Cheney–Gould, Cruz crown, FBP, Lautenberger, plus Viegas eruptive option) - Rothermel (1972) in all three - Semi-empirical QUIC; physics LES FIRETEC - Rothermel (1972) * - **Propagation method** - Eulerian level-set (WENO5-Z / RK3); FARSITE Huygens ellipse; MTT - FARSITE: Huygens wavelet; FlamMap: MTT or Huygens; BehavePlus: point (no spatial propagation) - Eulerian CFD (QUIC-URB / HIGRAD-FIRETEC) - Eulerian level-set on WRF grid * - **Crown fire** - Van Wagner (1977) + Rothermel (1991) + Cruz et al. (2005) + Scott–Reinhardt (2001) TI/CI - Van Wagner (1977); FARSITE/FlamMap active via R\ :sub:`c`\ = 3.34 R\ :sub:`s`; BehavePlus: Van Wagner point calc. - Physics-based combustion - Van Wagner (1977) * - **Wind adjustment** - WAF (Andrews 2018); MEWS cap; 7 wind-terrain feedback models - FARSITE/FlamMap: WAF + MEWS (internal); BehavePlus: user-specified WAF - 3-D mass-consistent (QUIC-URB) or LES - WRF-derived; WAF in coupling layer * - **Fuel models** - FBFM13 + FBFM40; FBP grass/slash; Lautenberger; per-cell LCP - FARSITE/FlamMap: FBFM13 + FBFM40; BehavePlus: FBFM13 + FBFM40 - Custom 3-D bulk density per cell - FBFM13 * - **Fuel moisture** - All size classes; FMD schedule; Nelson (2000) diurnal EMC; precipitation wetting; solar shading; per-cell .fms; spatial output in plotfiles - FARSITE/FlamMap: dead/live + FMD + conditioning; BehavePlus: dead/live per class - Bulk moisture per cell - Dead/live (prescribed) * - **Non-burnable masking** - ✓ Codes 91–99 / NB1–NB9 → ROS = 0 - ✓ (all three) - N/A (3-D grid) - Partial (fuel mask) * - **Flame diagnostics** - Byram intensity + flame length; scorch height; tree mortality; TI/CI; NFDRS ERC - FARSITE: intensity + flame length; FlamMap: full outputs; BehavePlus: full outputs - Physics heat release - Intensity + flame length * - **Firebrand spotting** - Albini (1983) 2-D trajectory + torching; stochastic distance model - FARSITE: Albini empirical; FlamMap: not standard; BehavePlus: Albini (point) - Select FIRETEC versions - Not included * - **Terrain & landscape** - Per-cell elev./slope/aspect/fuel from LCP or XYZ terrain file; 2-D domain - All three: full 2-D LCP landscape; BehavePlus: user slope/aspect - Full 3-D terrain + canopy - Full 3-D WRF terrain * - **Weather input** - Single .wtr; FMD schedule; **multi-station IDW** spatial interpolation - FARSITE: per-station .wtr; FlamMap: gridded or single station; BehavePlus: single point - Prescribed per-cell - WRF atmospheric profiles * - **Fire–atmosphere coupling** - None (prescribed wind; heat-flux plume correction optional) - None in all three - One-way QUIC-URB; two-way LES FIRETEC - Two-way (fire ↔ WRF) * - **Barrier / suppression** - Polyline firebreaks (CSV); aerial retardant (ROS + spotting suppressed) - FARSITE: dozer/hand lines + retardant; FlamMap/BehavePlus: not included - Not included - Not included * - **GPU acceleration** - ✓ AMReX CUDA / HIP / SYCL - ✗ (all three are serial / CPU-only) - Partial (QUIC-URB select versions) - ✗ * - **MPI parallelism** - ✓ AMReX domain decomposition - ✗ (all three serial) - ✓ MPI/OpenMP - ✓ WRF MPI * - **Embedded boundaries** - ✓ AMReX EB (buildings, fuel breaks) - ✗ (all three) - ✓ QUIC-URB / FIRETEC 3-D geometry - ✗ * - **Open source** - ✓ MIT licence - FARSITE/FlamMap: proprietary USFS binary; BehavePlus: open source - Research licence (QUIC-Fire); restricted (FIRETEC) - ✓ WRF open source Tool Documentation References ------------------------------ For authoritative and up-to-date information on each tool, refer to the official sources: * **Wildfire-AMR**: https://hgopalan.github.io/wildfire_levelset/ * **FARSITE**: https://www.firelab.org/project/farsite * **FlamMap**: https://www.firelab.org/project/flammap * **BehavePlus**: https://www.firelab.org/project/behaveplusfiremodeling * **QUIC-Fire**: https://www.lanl.gov/projects/quic-fire/ * **FIRETEC**: https://www.lanl.gov/org/padwp/adcles/fluid-dynamics-solid-mechanics/index.php * **WRF-SFIRE**: https://github.com/openwfm/WRF-SFIRE Key Differences from FARSITE ----------------------------- * **Eulerian level-set vs. explicit Huygens wavelets**: Wildfire-AMR embeds the same Richards (1990) elliptical directional spread as FARSITE inside an Eulerian level-set (WENO5-Z/RK3). The fire perimeter is the zero contour of a signed-distance function; merging fronts and islands are handled automatically without explicit connectivity management. * **Extended spread model library**: In addition to Rothermel (1972), Wildfire-AMR includes Balbi (2009) physics-based, Cheney–Gould (1995) Australian grassland, Cruz et al. (2005) crown fire, Canadian FBP O1a/O1b/S1–S3 (Forestry Canada 1992), and Lautenberger (2013) physics-based. FARSITE ships only with Rothermel (1972). * **Non-burnable cell masking**: Fuel model codes 91–99 and NB1–NB9 (water, rock, urban, bare ground) are explicitly zeroed in the ROS kernel so fire cannot creep through sparse-fuel numerical noise into non-burnable areas. * **Multiple weather stations**: ``multi_wtr_file`` loads per-station .wtr files and produces spatially-varying wind and T/RH via IDW interpolation, matching FARSITE's multi-station weather capability. * **Retardant spotting suppression**: ``retardant_file`` now suppresses both ROS and spotting probability inside active drop zones, consistent with FARSITE's aerial retardant model. * **Wind adjustments are optional**: FARSITE applies WAF and MEWS internally. Wildfire-AMR exposes both via ``rothermel.use_waf`` and ``rothermel.use_wind_limit`` so users can match FARSITE behaviour or supply midflame-height wind directly. * **GPU and MPI**: AMReX CUDA/HIP/SYCL kernels and MPI domain decomposition. FARSITE is serial and CPU-only. * **Embedded Boundary**: AMReX EB allows buildings and fuel breaks on the Cartesian grid without remeshing. FARSITE has no EB support. Key Differences from WRF-Fire (WRF-SFIRE) ------------------------------------------ * **No atmospheric coupling**: Wildfire-AMR uses prescribed wind fields (constant, CSV, or WRF output); WRF-SFIRE fully couples fire with WRF, including fire-induced wind, heat flux, and smoke transport. * **Wind adjustment**: When driving with WRF output, enable ``rothermel.use_waf = 1`` to convert NWP wind to midflame height. WRF-SFIRE handles this inside the coupled framework. * **Richer fire behaviour models**: WRF-SFIRE uses Rothermel (1972) only. Wildfire-AMR supports seven additional spread models and a richer crown fire pipeline (see above). * **Simpler setup**: Wildfire-AMR requires only CMake and AMReX; WRF-SFIRE requires a full WRF stack (NetCDF, MPI, WPS, WRF pre-processing). * **GPU-native kernels**: WRF-SFIRE is CPU-MPI; Wildfire-AMR uses AMReX GPU kernels throughout. Key Differences from FlamMap ----------------------------- * **Time-dependent propagation**: FlamMap computes static fire behaviour maps (no time stepping); Wildfire-AMR evolves the fire front dynamically via level-set, FARSITE Huygens, or MTT. * **Crown fire depth**: FlamMap provides the full Scott & Reinhardt (2001) crown fire assessment. Wildfire-AMR matches this with bisection-based TI/CI plus Van Wagner (1977) passive blending and Cruz et al. (2005) active crown ROS. * **GPU / open source**: FlamMap is a closed-source Windows binary; Wildfire-AMR is MIT-licensed and GPU-accelerated.