Landscape-toxicIntensity-method: toxicIntensity Method

In SEHmodel: Spatial Exposure-Hazard Model for Exposure and Impact Assessment on Exposed Individuals

Description

Simulate contaminants intensity over the landscape by two steps : dispersal of toxic particules and local intensity of particules after dispersal.

Usage

toxicIntensity(objectL, ...)

## S4 method for signature 'Landscape'
toxicIntensity(objectL, toxic_emission, mintime = 1,
  maxtime = 60, size_raster = 2^10, kernel = "NIG",
  kernel.options = list(a1 = 0.2073, a2 = 0.2073, b1 = 0.3971, b2 = 0.3971, b3
  = 0.0649, theta = 0), beta = 0.4, alpha = list(minalpha = 0.1, maxalpha =
  0.95, covariate_threshold = 30, simulate = T, covariate = NULL))

Arguments

objectL	A Landscape object
...	parameters
toxic_emission	Matrix of sources emissions, row as sources ID, col as time
mintime	Start simulation time (default=1)
maxtime	End simulation time
size_raster	raster size (default = 2^10)
kernel	dispersion kernel, function name (default = NIG)
kernel.options	parameters list for the kernel function
beta	toxic adherence parameter between 0 and 1 (default = 0.4)
alpha	list of toxic loss options (default = list(minalpha=0.1,maxalpha=0.95,covariate_threshold=30,simulate=TRUE,covariate=NULL))

Details

The dispersal of contaminants is implemented by rastering the landscape and by computing the convolution between sources emissions and a dispersal kernel.

The dispersion kernel by default is Normal Inverse Gaussian kernel ("NIG" function). Currently, two others are implemented "geometric" (with parameter a) and "2Dt" kernels (with parameters a, b, c1, c2).

Local intensity depends of beta and alpha parameters. Beta represents the toxic adherence between [0,1]. Alpha represents a list of parameters of the lost of toxic particules due to covariates (precipitation). There are two configurations to integrate the loss in the function : (i) simulating covariate (simulate=TRUE) or (ii) uploading covariate (simulate=FALSE). The covariate is linked to the loss by a linear regression with paramaters minalpha, maxalpha, covariate_threshold.

Value

A ToxicIntensityRaster, a 3D array as time matrix dispersion, [t,x,y]

SEHmodel documentation built on Sept. 12, 2016, 6:34 a.m.