X-ray computed microtomography in the evaluation of the porous system of soils

Microtomografia computadorizada de raios X na avaliação do sistema poroso de solos

ABSTRACT

Analysis of shapes, sizes, continuity, orientation and irregularities of pores can help in the study of soil structural modifications induced by soil management. The study of the inter- and intra-aggregate porous space of urban and rural soils by tomographic images is the objective of this work. A morphometric characterization of the pores was carried out with the analysis of distribution of their size, shape and inclination in these two types of soil. The urban soil showed smaller percentage of inter-aggregate voids and more intra-aggregate voids compared with the rural soil. The cumulative distribution of void volumes showed little pore diversity in the urban soil and great presence of large pores (48%), almost twice the voids with same size in the rural soil. The urban soil, compared to rural soil, also had a higher percentage of flattened pores (29.41%) and a smaller percentage of rounded voids (6.97%), as well as a greater percentage of horizontal voids (44.49%). Hence, the urban soil proved to be more compacted than the rural soil.

Key words:
porosity; tomographic images; soil compaction