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 fuel−final 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 1 4701\,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 1 4701\,470 generations, illustrating the slow exploration of marginally connected fuel paths near the crossover.

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