Mudanca textural abrupta (SiBCS Cap 1, p 30-31)
Source:R/diagnostics-atributos-sibcs.R
mudanca_textural_abrupta.Rd"Consiste em um consideravel aumento no teor de argila em pequena distancia na zona de transicao entre o horizonte A ou E e o horizonte subjacente B":
A or E with less than 200 g/kg of clay: the B has at least twice as much;
A or E with 200 g/kg or more: the B has 200 g/kg more or above ("de 300 para no minimo 500, ou de 220 para no minimo 420"),
"em uma distancia vertical <= 7,5 cm".
Arguments
- pedon
A
PedonRecord.
Value
A DiagnosticResult recording whether the diagnostic is present, the qualifying layers, and the supporting evidence.
Details
Since v0.9.244 the test is that of the book: the first B horizon is
compared with the horizon immediately above it, which has to be an A or
an E; and the distance is read from the distinctness of the transition
(boundary_distinctness of the horizon above: abrupt, under 2.5 cm,
or clear, 2.5 to 7.5 cm). Where it is recorded as gradual or diffuse there
is no abrupt change; where it is not recorded the two horizons are
compared. The layer returned is the first B horizon. A BA is a B horizon
here and a BC is not, as in item (h) of the B textural.
Until v0.9.243 the function was the WRB
abrupt_textural_difference, which compares every pair of
adjoining layers, in the order of the rows: a jump of clay between two B
horizons, or from a B to a C, was an abrupt change. A profile with no
horizon designation at all is still tested that way.