vegpfromhab: Generate vegpetation paramaters form habitat type

In ilyamaclean/microclimf: Fast above, below or within canopy gridded microclimate modelling with R

Generate vegpetation paramaters form habitat type

Description

The function 'vegpfromhab' generates an object of class vegparams from a SpatRaster object of habitat types

Usage

vegpfromhab(habitats, hgts = NA, pai = NA, lat, long, tme, clump0 = TRUE)

Arguments

habitats	a SpatRaster object of habitat types expressed as integers (see details)
hgts	an optional SpatRaster object of vegetation heights. Estimated from habitat type if not provided.
pai	an optional array of plant area index values. Estimated at monthly intervals from habitat type, with seasonal variation dtermined form location and date if not provided.
lat	latitude in decimal degrees. Only needed if 'pai' not provided.
long	longitude in decimal degrees. Only needed if 'pai' not provided.
tme	POSIXlt object of dates. Only needed if 'pai' not provided (see details).
clump0	optional logical, which if TRUE sets the canopy clumping factor to 0, and if false, estimates it using [clumpestimate()]

Details

This function estimates the vegetation parameters needed to run microclimf from habitat types. Plant area index values represent the combined one sided woody and green vegetation plant area per unit ground area. If not provided, then approximated from habitat type, location and date. The procedure is based on calibration against MODIS-derived estimates, accounting for regional climate. An inbuilt dataset of regional rainfall and temperature is included with the package. Monthly values for each unique month in 'tme' are returned. Note that values are assumed spatially constant across a given habitat type, which is unlikely to be the case in reality. Likewise, if vegetation height values are not provided, these are estimated form habitat type and assumed constant within that habitat type. Habitat types should be expressed as integers as follows: (1) for Evergreen needleleaf forest, (2) for Evergreen broadleaf forest, (3) for Deciduous needleleaf forest, (4) for Deciduous broadleaf forest, (5) for Mixed forest, (6) for Closed shrubland, (7) for Open shrubland, (8) for Woody savanna, (9) for Savanna, (10) for Short grassland, (11) for Tall grassland, (12) for Permanent wetland, (13) for Cropland, (14) for Urban and built-up, (15) for Cropland / Natural vegetation mosaic and (16) for Barren or sparsely vegetated

Value

an object of class vegparams - a list with the following elements:

'pai' an array of monthly plant area index values (see details).

'hgt' a SpatRaster object if vegetation heights (m)

'x' a SpatRaster object of ratios of vertical to horizontal projections of leaf foliage

'gsmax' a SpatRaster object of maximum stomatal conductances (mol / m^2 / s)

'leafr' a SpatRaster object of leaf reflectance values (to shortwave radiation)

'clump' an array of monthly values indicating the degree of canopy clumpiness, by default set to 0 (vegetation not clumped)

'leafd' a SpatRaster object of mean leaf widths (m)

'leaft' a SpatRaster object of mean leaf transmittance (m)

Examples

library(terra)
tme<-as.POSIXlt(c(0:8783)*3600,origin="2000-01-01 00:00", tz = "GMT")
veg<-vegpfromhab(habitats,lat=50,long=-5,tme=tme)
plot(rast(veg$pai[,,1]), main = "Jan PAI")
plot(veg$hgt, main = "Vegetation height")
plot(veg$x, main = "Leaf angle coefficient")
plot(veg$gsmax, main = "Maximum stomatal conductance")
plot(veg$leafr, main = "Leaf reflectance")
plot(rast(veg$clump[,,1]), main = "Canopy clumping factor")
plot(veg$leafd, main = "Leaf diameter")
plot(veg$leaft, main = "Leaf transmittance")

ilyamaclean/microclimf documentation built on Sept. 28, 2024, 4:55 p.m.