arboreal: Fire risk for an exposed arboreal animal

In pzylstra/Impact: Fire impact functions for FRaME

Description

Calculates the degree of injury or likelihood of mortality to an animal caused by an approaching fire front

Usage

arboreal(
  Surf,
  Plant,
  percentile = 0.5,
  Height = 1,
  low = 1,
  high = 50,
  var = 10,
  Pressure = 1013.25,
  Altitude = 0,
  RH = 0.51,
  Class = "mammalia",
  Dimension = 0.1,
  Area = 0.2,
  protection = 0.02,
  count = 66,
  fibre = 0.01,
  Specific_heat = 2.5,
  skinCp = 3.5,
  skinK = 2,
  objectTemp = 38,
  Shape = "Flat",
  updateProgress = NULL
)

Arguments

Surf	The dataframe 'runs' exported from Monte Carlos as 'Summary.csv'
Plant	The dataframe 'IP' exported from Monte Carlos as 'IP.csv'.
percentile	defines which heating statistics are used for each second, from 0 (min) to 1 (max)
Height	The height directly ove ground (m) at which the species is expected to shelter from a fire.
low	The closest horizontal distance between the flame origin and the point (m)
high	The furthest horizontal distance between the flame origin and the point (m)
var	The angle in degrees that the plume spreads above/below a central vector
Pressure	Sea level atmospheric pressure (hPa)
Altitude	Height above sea level (m)
RH	The relative humidity (0-1)
Class	Class of animal. Allowable values are "mammalia", "aves", "amphibia" and "reptilia"
Dimension	The "Characteristic length" of the animal (m)
Area	The surface area of the animal (m^2)
protection	The thickness of fur, feather or scales covering the animal (m)
count	The number of fibres per square mm
fibre	The mean fibre diameter of hairs in mm
Specific_heat	The specific heat of the fur, feather or scale material only (kJ/kg/deg C)
skinCp	The specific heat of the animal skin (kJ/kg/C)
skinK	Thermal conductivity of the animal skin (W/m/C)
objectTemp	The body temperature of the animal (deg C)
Shape	The approximate shape of the animal - either "Flat", "Sphere", or "Cylinder"
updateProgress	Progress bar for use in the dashboard

Details

Utilises the output tables from 'threat' and 'radiation', and adds to these the Reynolds Number, heat transfer coefficients, Newton's convective energy transfer coefficient, and the temperature of the object each second.

Reynolds Number utilises a standard formulation (e.g. Gordon, N. T., McMahon, T. A. & Finlayson, B. L. Stream hydrology: an introduction for ecologists. (Wiley, 1992))

Convective heat transfer coefficients use the widely adopted formulations of Williams, F. A. Urban and wildland fire phenomenology. Prog. Energy Combust. Sci. 8, 317–354 (1982), and Drysdale, D. An introduction to fire dynamics. (John Wiley and Sons, 1985) utilising a Prandtl number of 0.7.

Mammal pelage is given a standardised emissivity of 0.86, based on: McGowan, N. E., Scantlebury, D. M., Maule, A. G. & Marks, N. J. Measuring the emissivity of mammal pelage. Quant. Infrared Thermogr. J. 6733, 1–9 (2018).

Skin Cp is set to 3.5, averaged from Duck, F. A. Physical properties of tissues: a comprehensive reference book. (Elsevier Science, 1990).

Finds furDensity - the density of fur or feathers on the animal using standard values of 66 fibres per mm2, fibre diameter of 0.01mm (10μm), and α-keratin density of 1300 kg.m-3. Fibre count averaged from Liwanag, H. E. M., Berta, A., Costa, D. P., Abney, M. & Williams, T. M. Morphological and thermal properties of mammalian insulation: the evolution of fur for aquatic living. Biol. J. Linn. Soc. 106, 926–939 (2012)

Finds thermal dose from all heat inputs, using the formula from Ciesielski, M., Mochnacki, B. & Szopa, R. Numerical modeling of biological tissue heating. Admissible thermal dose. Sci. Res. Inst. Math. Comput. Sci. 10, 11–20 (2011).

Value

dataframe

pzylstra/Impact documentation built on April 1, 2021, 2:32 a.m.