aqp (version 1.27)

getSurfaceHorizonDepth: Determine thickness of horizons (continuous from surface) matching a pattern

Description

This function is used to find the thickness of arbitrary horizon designations that are continuous from the soil surface (depth = 0).

The horizon designation to match is specified with the regular expression pattern 'pattern'. All horizons matching that pattern, that are continuous from the soil surface, count towards the depth / thickness value that is ultimately returned. For instance: horizon designations: A1-A2-A3-C-Ab , would return A3 bottom depth given pattern = "A".

getSurfaceHorizonDepth is used by getPlowLayerDepth for matching Ap horizons; and, it is used by getMineralSoilSurfaceDepth to find the thickness of O horizons in lieu of lab data.

Usage

getMineralSoilSurfaceDepth(p, hzdesgn = guessHzDesgnName(p), pattern = "O")
getPlowLayerDepth(p, hzdesgn = guessHzDesgnName(p), pattern = "^Ap[^b]*")

Arguments

p

A single-profile SoilProfileCollection object.

pattern

Regular expression pattern to match for all horizons to be considered part of the "surface".

hzdesgn

Column name containing horizon designation. Default: guessHzDesgnName(p).

Value

Returns a numeric value corresponding to the bottom depth of the last horizon matching 'pattern' that is contiguous with other matching horizons up to the soil surface (depth = 0).

Examples

# NOT RUN {
library(aqp)
data(sp1, package = 'aqp')
depths(sp1) <- id ~ top + bottom
site(sp1) <- ~ group

p <- sp1[1]
q <- sp1[2]

# look at horizon designations in p and q
p$name
q$name

# thickness of all surface horizons containing A
getSurfaceHorizonDepth(p, pattern = 'A', hzdesgn = 'name')

# thickness of all surface horizons that start with A
getSurfaceHorizonDepth(p, pattern = '^A', hzdesgn = 'name')

# thickness of all surface horizons that start with A, and the A is not followed by B
getSurfaceHorizonDepth(p, pattern = '^A[^B]*', hzdesgn = 'name')

# thickness of all surface horizons that start with A
#  followed by a number from _2_ to 9 (returns ZERO)
getSurfaceHorizonDepth(p, pattern = '^A[2-9]*', hzdesgn = 'name')

# getPlowLayerDepth matches first two horizons in fake Ap horizon data with "buried Ap"
p$aphorizons <- c("Ap1","Ap2","AB", rep('C', nrow(p) - 4), "Apb")
getPlowLayerDepth(p, hzdesgn = 'aphorizons')

# getMineralSoilSurfaceDepthmatches first 3 horizons in fake O horizon data
p$ohorizons <- c("Oi1","Oi2","Oe", rep('C', nrow(p) - 4), "2C")
getMineralSoilSurfaceDepth(p, hzdesgn='ohorizons')

# matches first Oi horizon with original horizon designations of pedon 2
getMineralSoilSurfaceDepth(q, hzdesgn='name')

# }