Knowledge of physical and mechanical properties of geomaterials is fundamental to characterise their response to external mechanical and climatic forcings at various scales. This is true in slope stability assessments, civil engineering works, and agriculture.

The direct evaluation soil properties in situ can be difficult, especially in inaccessible or vast areas, and so can be the sampling and subsequent testing in the laboratory. Empirical correlations with more readily determinable quantities remain a powerful and practical tool.

In this study, we proposed a simple method to evaluate the porosity and friction angle of soils via infrared thermography, consisting of periodic acquisitions of images in infrared wavelengths.

To demonstrate the method’s capability, we analysed the cooling behaviour of well-studied bentonite, kaolin, and sand samples. We interpreted the results through a specially defined cooling rate index (CRI). We found that the CRI correlates well with the friction angle and that different soils have unique relationships between their porosity and the CRI.

Although a systematic investigation on a wide range of natural soils is warranted, we argue that our method is highly informative and could be used to calibrate remote sensing-based full-scale implementations in situ for various purposes.

Loche, Scaringi, Blahůt, Hartvich (2022), Remote Sensing.
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