04 Vadose Zone Physics

04-01 Soil Properties

Basic physical characteristics influencing unsaturated flow: texture, structure, porosity, bulk density, and pore-size distribution.

Index	Description
04-01-001	Soil Texture Triangle
04-01-002	Soil Texture Classes

04-01-001Soil Texture Triangle

Type: Jupyter Notebook

Time: 5–15 min

Figure 1: Screenshot of the Jupyter Notebook (Screenshot)

This Notebook illustrates how the percentages of the particle-size classes sand, silt, and clay determine the soil texture and how these can be read from a soil texture triangle.

LAUNCH RESOURCE

Detail	Value
URL	github.com · open repository
Author(s)	Steffen Birk (Universität Graz, Institut für Erdwissenschaften); Edith Griesser (Universität Graz, Institut für Erdwissenschaften)
Keywords	soil classification
Fit For	exam preparation
Prerequisites	None

04-01-002Soil Texture Classes

Type: Streamlit app

Time: 5–15 min

Figure 1: The soil triangle diagram. (Screenshot)

This interactive Streamlit app helps learners understand how the relative proportions of sand, silt, and clay define a soil texture class in a soil texture triangle (e.g., FAO, 2006). A randomly generated soil sample is displayed as a red point in a ternary diagram, and users estimate the corresponding percentages by entering values for clay, sand, and silt.

After submitting their guess, the app provides instant feedback indicating which components are correct or incorrect. A restart button generates a new sample point so users can practice repeatedly and build intuition for reading and interpreting soil texture triangles.