Module 2 · Soil sampling design

Digital Soil Mapping
A three-stage probabilistic sampling design (PSU/SSU/TSU) using covariate space coverage, land-use strata and climate (Newhall) regimes.

Format: 2 steps · Level: Intermediate · Runs in: Google Colab (R) · Material: SoilFER Training Manual + Training Resources

Read the manual chapter

What you will learn

  • prepare environmental covariates in Google Earth Engine
  • derive soil climate regimes with the Newhall model
  • design PSU/SSU/TSU samples with covariate space coverage
  • check sample size and replacement units

Notebooks

Each notebook opens in Google Colab with the R runtime. Run the Setup cell first: it downloads the training project, installs the R packages and gets the course data. Then run the cells in order.

Notebook
Step 1 · Climate data and soil-climate covariates (Newhall model)

Open in Colab.ipynb
Step 2 · Three-stage sampling design with covariate space coverage

Open in Colab.ipynb
ImportantBefore Step 1: Google Earth Engine

Run 02_scripts/module2/gee_soilfer_env_covariates.txt in the GEE Code Editor and share the export folder in your Google Drive (Anyone with the link → Viewer). The Step 1 notebook has a cell where you paste that link.

A full national design runs for many hours, longer than a Colab session allows: use the Kansas example or one region in Colab.

First time in Colab? Read Getting started.

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