Group

Variable

Reference

Unit

Pedology

Soil type

[16]

Class name

Spectral

NDVI

[17]

Non-dimensional

Topography

Elevation

[18]

m

Slope

Degree (˚)

Aspect

Degree (˚)

Geomorfology

Geom

[19]

Class name

Geology

Dist. of geological structures

km

Lithology

Class name

Max. Age of rocks

Millions of years (Ma)

Average age of rocks

Min. age of rocks

Climate

precipitation

[20]

mm

Max.temp.

˚C

Avg. temp.

˚C

Min. temp.

˚C

Range temp.

˚C