Feasibility study of estimating the porosity of soils from sound absorption measurements

• We describe the estimation of soil porosity by measurement of the sound absorption.
• We obtained a very good correlation between porosity and the mean sound absorption coefficient.
• The method is a feasible technique to be implemented in the forestry and agricultural sectors.

This feasibility study describes a novel method to estimate porosity of soil by measurements of the sound absorption coefficient. Several samples of forest soil were taken and subjected to various environmental treatments to alter their humidity content. Measurements of the sound absorption coefficient were conducted on these samples. The mean sound absorption was then calculated as a single characteristic value. Porosity and volumetric moisture for each sample were determined. The results suggested a very good correlation between porosity and the mean absorption coefficient. The highest absorption values were obtained for samples in dry state, while lowest absorption values were found from samples in a saturated state, confirming the highly determinant effect of porosity on the absorption coefficient. Finally, by means of a statistical analysis, linear coefficients that relate the average absorption coefficient and porosity were determined.