hollow: Fire risk for an animal sheltering in a wooden hollow

In pzylstra/Impact: Fire impact functions for FRaME

Description

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

Usage

hollow(
  Surf,
  Plant,
  percentile = 0.5,
  Height = 1,
  woodDensity = 700,
  barkDensity = 500,
  wood = 0.1,
  bark = 0.02,
  RH = 0.2,
  water = 0.2,
  low = 1,
  high = 50,
  var = 10,
  Pressure = 1013.25,
  Altitude = 0,
  Dimension = 0.3,
  Area = 0.03,
  hollowTemp = 25,
  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 over ground (m) at which the species is expected to shelter from a fire.
woodDensity	The density of wood in the tree or log housing the hollow (kg/m3)
barkDensity	The density of bark in the tree or log housing the hollow (kg/m3)
wood	The thickness of wood on the thinnest side of the hollow (m)
bark	The thickness of bark on the thinnest side of the hollow (m)
RH	The relative humidity (0-1)
water	The proportion oven-dry weight of moisture in the bark and wood
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;defaults to 10
Pressure	Sea level atmospheric pressure (hPa)
Altitude	Height above sea level (m)
Dimension	The "Characteristic length" of the hollow (m)
Area	The surface area of the thinnest side of the hollow (m^2)
hollowTemp	The starting temperature inside the hollow (deg C)
Shape	The approximate shape of the hollow exterior - 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.

Finds animal mortality within a hollow based on the maximum tolerable temperature for a given vapour pressure deficit, based on data from Lawrence, G. E. Ecology of vertebrate animals in relation to chaparral fire in the Sierra Nevada foothills. Ecology 47, 278–291 (1966)

Heat is transferred into the hollow using Fourier's Law

Thermal conductivity of bark is modelled as per Martin, R. E. Thermal properties of bark. For. Prod. J. 13, 419–426 (1963)

Specific heat of bark is modelled using Kain, G., Barbu, M. C., Hinterreiter, S., Richter, K. & Petutschnigg, A. Using bark as a heat insulation material. BioResources 8, 3718–3731 (2013)

Thermal conductivity of wood is modelled using an approach from Kollmann, F. F. P. & Cote, W. A. Principles of wood science and technology I. Solid wood. (Springer-Verlag, 1968)

Evaporates water at 100 degrees C

Specific heat of wood is derived from an established empirical relationship in Volbehr, B. Swelling of wood fiber. PhD Thesis. (University of Kiel, 1896)

Value

dataframe

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