
Test for stagnic redox features (perched water signature)
Source:R/utils-diagnostic-tests.R
test_stagnic_pattern.RdDistinct from gleyic (groundwater): stagnic = redoximorphic features
in some layer within the upper max_top_cm (default 100) AND
redox in deeper layers DROPS substantially (decay to < third of the
shallow value). The decay condition is what separates perched water
(sits above an impermeable layer; deeper soil is not saturated)
from groundwater-driven gleying (saturation continues with depth).