Evaluating criteria for the "arbitrary control section" depths used in the Histosols and Histels.

This relies on code being used in the new branch ncss-tech/aqp@mollic

[snip]

This calculates theoretical surface tier thickness not truncated to RLL

surface.tier.thickness <- profileApply(r02_histosols, histosol.surface.tier)

4 out of 5 RO2 Histosols (81%) have the 0-30cm surface tier (i.e. do not have fibric in 0-60cm)
NB: even without checking sphagnum content or bulk density, we can see this case is not common in RO2.

> prop.table(table(surface.tier.thickness))
surface.tier.thickness
       30        60 
0.8178439 0.1821561 
 

# Calculate control section top and bottom depths
#  these are truncated to RLL where appropriate, and use the surface tier thickness calculated
hcs.bounds <- profileApply(r02_histosols, histosol.control.section, frameify = TRUE)

sum(hcs.bounds$hcs_b > 130) / nrow(hcs.bounds)
sum(hcs.bounds$hcs_b == 160) / nrow(hcs.bounds)

• Approximately 7.5% of RO2 histosols have a CS bottom depth >130cm
• Approximately 3% of RO2 histosols CS descriptions actually extend to 160cm