Game of Life: Tribes

#Wildfire Analysis

#Preset Dynamics

The active-fire lifecycle is deterministic: Blaze → Fire → Ember → Char.
All 33 active-fire states count equally as burning neighbors. Vegetation resistance determines both whether ignition occurs and its initial intensity:

Vegetation Ember at Fire at Blaze at
Grass 1\geq1 burning neighbor 2\geq2 3\geq3
Bush 2\geq2 burning neighbors 3\geq3 4\geq4
Tree 3\geq3 burning neighbors 4\geq4 5\geq5

Wildfire state transitions

Grass, Bush, Tree, and Char otherwise remain unchanged.

#Derived Metrics

Initial fuel is the first recorded Grass + Bush + Tree population. Total burn fraction is:

initial fuelfinal fuelinitial fuel\frac{\text{initial fuel}-\text{final fuel}}{\text{initial fuel}}

Vegetation-specific burn fractions use the same formula separately for Grass, Bush, and Tree. Active fire is simply Ember + Fire + Blaze.

  • Fire duration: final active-fire generation minus first recorded generation.
  • Peak active fire: largest active-fire count divided by initial fuel.
  • Time to peak: peak generation minus first recorded generation.
  • Maximum burn rate: largest positive 11-generation loss of Grass, Bush, and Tree, divided by initial fuel.
  • Cumulative burn fraction: fuel lost up to each generation, divided by initial fuel.

#Outcome Distribution

At low and intermediate densities, the seeded fire usually remains local. Median burn fraction is 0.0110%0.0110\% at 50%50\% density and 0.0819%0.0819\% at 80%80\%. At 100%100\%, the median is 87.469%87.469\%; even a fully occupied grid does not imply total consumption because resistant Tree clusters can remain after the fire front disappears.

Wildfire outcome distribution across all sampled densities

The detailed sweep shows a sharp crossover around 90%90\%:

Density Median burned Q25\mathbf{Q}_{25} Q75\mathbf{Q}_{75} IQR
85%85\% 0.251%0.251\% 0.117%0.117\% 0.411%0.411\% 0.295 pp0.295\text{ pp}
86%86\% 0.363%0.363\% 0.220%0.220\% 0.629%0.629\% 0.409 pp0.409\text{ pp}
87%87\% 0.632%0.632\% 0.432%0.432\% 1.537%1.537\% 1.105 pp1.105\text{ pp}
88%88\% 1.429%1.429\% 0.706%0.706\% 2.405%2.405\% 1.700 pp1.700\text{ pp}
89%89\% 3.756%3.756\% 0.901%0.901\% 11.439%11.439\% 10.538 pp10.538\text{ pp}
90%90\% 27.629%27.629\% 2.475%2.475\% 39.797%39.797\% 37.321 pp37.321\text{ pp}
91%91\% 53.329%53.329\% 52.187%52.187\% 54.530%54.530\% 2.343 pp2.343\text{ pp}
92%92\% 60.496%60.496\% 59.043%59.043\% 60.991%60.991\% 1.948 pp1.948\text{ pp}
93%93\% 64.753%64.753\% 64.201%64.201\% 65.743%65.743\% 1.542 pp1.542\text{ pp}
94%94\% 68.655%68.655\% 68.100%68.100\% 68.957%68.957\% 0.857 pp0.857\text{ pp}
95%95\% 72.015%72.015\% 71.628%71.628\% 72.364%72.364\% 0.736 pp0.736\text{ pp}

The IQR peaks at 90%90\%, where identical density settings produce both rapid fadeouts and large burns. It then collapses at 91%91\% as large connected burns become the dominant outcome.

Wildfire burn-fraction IQR

Rare fadeouts still persist above the central crossover. At 91%91\%, 33 of 3030 runs burn less than 1%1\%, while 2626 burn more than 50%50\%. At 93%93\%, 11 run burns 1.234%1.234\% and the other 2929 exceed 50%50\%.

Wildfire regime-change highlight

#Vegetation Type

Median loss follows Grass > Bush > Tree at every sampled density, matching the preset's ordered ignition thresholds.

Density Grass burned Bush burned Tree burned
89%89\% 5.72%5.72\% 3.84%3.84\% 1.72%1.72\%
90%90\% 41.68%41.68\% 28.17%28.17\% 13.01%13.01\%
91%91\% 78.74%78.74\% 55.12%55.12\% 26.39%26.39\%
95%95\% 95.24%95.24\% 76.44%76.44\% 44.48%44.48\%
100%100\% 99.28%99.28\% 91.93%91.93\% 71.20%71.20\%

These are fractions of each vegetation type's own initial population, not shares of all burned cells.

Burn fraction by vegetation type

#Fire Dynamics

Duration is longest and most variable around the crossover. Median duration rises from 332332 generations at 89%89\% to 855.5855.5 at 90%90\%, then falls to 738.5738.5 at 91%91\%, 592.5592.5 at 92%92\%, and 383383 at 100%100\%. The longest individual run lasts 14701\,470 generations at 89%89\%.

At the same time, intensity rises with density. Median peak active-fire fraction is 0.0480%0.0480\% at 89%89\%, 0.1038%0.1038\% at 90%90\%, 0.2399%0.2399\% at 91%91\%, and 0.8482%0.8482\% at 100%100\%. Median maximum burn rate rises from 0.0347%0.0347\% of initial fuel per generation at 89%89\% to 0.5274%0.5274\% at 100%100\%.

Together, these results distinguish 22 effects: near the crossover, uncertain connectivity produces long, variable exploration of the fuel network; above it, broader fronts consume fuel more intensely and finish sooner.

Wildfire duration, peak, time-to-peak, and burn-rate metrics

#Trajectories And Representative Runs

Individual cumulative-burn trajectories separate into distinct fadeout and sustained-spread outcomes near 90%90\%. The transition figure selects 90%90\% runs nearest the 10th10^{\text{th}}, 50th50^{\text{th}}, and 90th90^{\text{th}} burn-fraction percentiles:

Representative role Run Burned Duration
Nearest p10\mathrm{p}_{10} 77 0.678%0.678\% 141141
Nearest p50\mathrm{p}_{50} 2828 27.324%27.324\% 587587
Nearest p90\mathrm{p}_{90} 55 43.984%43.984\% 904904

Wildfire trajectories by density

Representative Wildfire transition runs

#Transition Runs In Motion

The 33 recordings below use the same 90%90\% density and correspond to the representative runs in the table and figure above. Together they show how randomized initial vegetation layouts produce rapid fadeout, intermediate spread, or a large burn even though the subsequent Wildfire evolution is deterministic.

Low outcome – Run 7\mathbf{7} Median outcome – Run 28\mathbf{28} High outcome – Run 5\mathbf{5}
0.678%0.678\% burned
141141 generations
27.324%27.324\% burned
587587 generations
43.984%43.984\% burned
904904 generations

#Typical Runs Across Regimes

The 50%50\% run is intentionally brief: its 44-generation fadeout is representative of a regime in which fire cannot find a connected path through the fuel. The 100%100\% run shows the contrasting broad fire front and the survival of some resistant vegetation.

Typical 50%\mathbf{50\%} – Run 24\mathbf{24} Typical 100%\mathbf{100\%} – Run 6\mathbf{6}
0.0114%0.0114\% burned
44 generations
87.470%87.470\% burned
381381 generations

#Long-Lived Near-Transition Fire

The longest Wildfire run in the dataset occurs at 89%89\% density. Run 55 burns 27.875%27.875\% of its initial fuel over 14701\,470 generations, illustrating the slow exploration of marginally connected fuel paths near the crossover.

Game of Life: Tribes · Simulation v1.0.0 · Open source