From: Modeling fuel break effectiveness in southern Spain wildfires
Variables | Source | Range | Type | Units or categories |
---|---|---|---|---|
Topographic variables | ||||
Slope | INFOCA | 0–65 | Qn | % |
Aspect | INFOCA | 1–2 | Ql | 1 (sunshine) 2 (shade) |
Meteorological variables | ||||
Temperature | SIAR 2021 | 4.85–43.47 | Qn | °C |
Relative humidity | SIAR 2021 | 6.14–85 | Qn | % |
Wind speed (U) | SIAR 2021 | 0–32 | Qn | km/h |
Fuel variables | ||||
Fine fuel moisture content (FFMC) (Rothermel 1983) | Own data | 6.25–13.63 | Qn | % |
Fuel model (UCO 40) (FM) (Molina and Rodríguez y Silva 2012) | Own data from INFOCA report (conversion of Rothermel classification to UCO 40) | 1–12 | Ql | 1 (grass in semiarid conditions; P1, P2. P3, P4, P7) 2 (grass in subhumid conditions; P5, P6, P8) 3 (mixture of grass and shrubs lower than 60 cm high; PM1, PM3) 4 (mixture of grass and shrub higher than 60 cm high; PM2, PM4) 5 (shrub lower than 0.5 m high; M1, M2) 6 (shrub approximately 1 m in height; M3, M4, M6) 7 (chaparral shrub; M5, M7, M8, M9) 8 (grass, shrub, or litter lower than 30 cm in height or depth; HPM1, HPM2) 9 (grass, shrub, or litter between 30 and 90 cm in height or depth; HPM3, HPM4) 10 (grass, shrub, or litter more than 90 cm in height or depth; HPM5) 11 (slash and pine litter; HR5, HR7) 12 (slash and broadleaf litter; HR6, HR9, R1) |
Fuel break design features | ||||
Fuel break type (PIT) | INFOCA | 1–3 | Ql | 1 (vegetation-free: firebreak) 2 (combination of vegetation-free and vegetated: firebreak with adjacent vegetation-treated area) 3 (vegetated: vegetation treated area) |
Fuel break location (LOC) | Own data | 1–6 | Ql | 1 (steepest slope) 2 (flat) 3 (ridgeline) 4 (lower slope) 5 (mid-slope) 6 (canyon bottom) |
Fuel break width (W) | Own data | 1.5–450 | Qn | m |
Suppression variables | ||||
Type of suppression work executed on fuel break (SW) | INFOCA | 1–5 | Ql | 1 (combined ground-aerial firefighting) 2 (ground firefighting) 3 (aerial firefighting) 4 (fire spread with no suppression due to technical reasons) 5 (fire spread with no suppression due to safety reasons) |
Firefighter safety | INFOCA | 0–2 | Ql | 0 (non-safe) 1 (safe) 2 (unknown) |
Fuel break effectiveness (EFFEC) representing if the fire spread was controlled in the fuel break | Own data | 0–1 | Ql | 0 (non-effective) 1 (effective) |
Cause of fuel break leap | INFOCA | 1–4 | Ql | 1 (no leap) 2 (radiation-convection) 3 (spotting) 4 (radiation-convection and spotting) |
Observed fire characteristics | ||||
Wildfire type (WT) | INFOCA | 1–3 | Ql | 1 (surface fire) 2 (passive crown fire) 3 (active crown fire) |
Burned area | INFOCA | 0.02–9806 | Qn | ha |
Wildfire front length (L) representing the length of the portion of fire that encountered the fuel break | INFOCA | 1–8 | Ql | 1 (< 50 m) 2 (50–100 m) 3 (100–250 m) 4 (250–400 m) 5 (400–600 m) 6 (600–800 m) 7 (800–1000 m) 8 (> 1000 m) |
Alignment of forces (AF) (Campbell 2005) representing the arrangement of various factors that influence the behavior and spread of a wildfire (wind, slope, and preheat) | Own data | 0–3 | Ql | 0 (0/3; out of alignment) 1 (1/3; half alignment: one factor) 2 (2/3; half alignment: two factors) 3 (3/3; full alignment: wind, slope, and preheat) |
Propagation vector | INFOCA | 1–4 | Ql | 1 (fuel) 2 (wind) 3 (topography) 4 (convective) |
Intersection angle between fire and fuel break (encounter type) (ANG) | Own data | 1–3 | Ql | 1 (almost parallel, flanking) 2 (lateral, flanking) 3 (perpendicular, heading) |
Predicted fire behavior | ||||
Rate of spread (ROS) (Andrews 2009) | Own data | 0.1–263 | Qn | m/min |
Flame length (FL) (Byram 1959) | Own data | 0.1–17.15 | Qn | m |
Spotting distance (Albini 1976) | Own data | 0.8–288.35 | Qn | m |