Modifications to the porosity of clay, loam and sand soils by infiltration of water were studied on undisturbed soil columns (dia. 5.5 cm and length 25 cm). Porosity (>30 microns), pore shape, pore size distribution and pore length were measured on thin sections by image analyzing computer. The area occupied by pores, their numbers and the length of elongated pores decreased with the increased amount of infiltrated water. Modifications in pore size distribution also occurred. These changes were relatively rapid with initial quantities of infiltrated water and were more in 0–0.05 m than in the 0.15–0.20 m depths. The changes were maximum in clay and minimum in sand.
MOdifications to porosity, water infiltration, thin section, image analysis, elongated pores
