A collection of 18 soil profiles, consisting of select soil morphologic attributes, associated with a stratigraphic study conducted near Honcut Creek, California.
A data frame with 154 observations on the following 21 variables.
profile id
dated surface
horizon top in cm
horizon bottom in cm
horizon lower boundary distinctness class
horizon lower boundary topography class
horizon name
USDA soil texture class
field-estimated clay content
soil structure grade
soil structure size
soil structure type
stickiness
plasticity
field-measured pH
Munsell hue
Munsell value
Munsell chroma
RGB red component
RGB green component
RGB blue component
R-friendly encoding of soil color
Busacca, Alan J.; Singer, Michael J.; Verosub, Kenneth L. 1989. Late Cenozoic stratigraphy of the Feather and Yuba rivers area, California, with a section on soil development in mixed alluvium at Honcut Creek. USGS Bulletin 1590-G.
# keep examples from using more than 2 cores
data.table::setDTthreads(Sys.getenv("OMP_THREAD_LIMIT", unset = 2))
data(sp2)
# convert into SoilProfileCollection object
depths(sp2) <- id ~ top + bottom
# transfer site-level data
site(sp2) <- ~ surface
# generate a new plotting order, based on the dated surface each soil was described on
p.order <- order(sp2$surface)
# plot
par(mar=c(1,0,3,0))
plot(sp2, plot.order=p.order)
# setup multi-figure output
par(mfrow=c(2,1), mar=c(0,0,1,0))
# truncate plot to 200 cm depth
plot(sp2, plot.order=p.order, max.depth=200)
abline(h=200, lty=2, lwd=2)
# compute numerical distances between profiles
# based on select horizon-level properties, to a depth of 200 cm
d <- NCSP(sp2, vars=c('prop','field_ph','hue'), maxDepth = 100, k = 0)
#> Computing dissimilarity matrices from 18 profiles
#> [0.4 Mb]
# plot dendrogram with ape package:
if(require(ape) & require(cluster)) {
h <- diana(d)
p <- as.phylo(as.hclust(h))
plot(p, cex=0.75, label.offset=0.01, font=1, direct='down', srt=90, adj=0.5, y.lim=c(-0.125, 0.5))
# add in the dated surface type via color
tiplabels(col=as.numeric(sp2$surface), pch=15)
# based on distance matrix values, YMMV
legend('topleft', legend=levels(sp2$surface), col=1:6, pch=15, bty='n', bg='white', cex=0.75)
}
#> Loading required package: ape
#> Loading required package: cluster