ABSTRACT
An aggregate is analogous to a building. The functional space of a building includes rooms, interconnecting corridors, and exit and entrance doors that facilitate communication with the exterior. Stability of the exterior and interior walls is important to maintaining functions of all rooms and interconnecting corridors. Continuity of corridors is extremely important for the building to remain functional. Similar to the walls of a building, skeleton structure of microaggregates and aggregates is important to maintaining size, stability, and continuity of pores within and between aggregates. The porosity, or soil architecture, is the functional entity of soil structure. Soil, similar to a building, becomes dysfunctional as soon as it loses its pores and their continuity within the soil profile and to the atmosphere. Therefore, soil structural characterization cannot be complete without assessment of its porosity, pore size distribution, and continuity. Because aggregates are highly dynamic and transient, varying in time and space and ranging in scale from A to a few cm, so are pores. Porosity is a complex and a moving target, that governs the essence of biological processes that supports life and biochemical and physical processes that determine environment quality. It is this complexity which leads to a wide range of terminology, e.g., porosity, pore, pore space, pore size distribution, voids, channels, biochannels and biopore or macropores, cracks, fissures, fractures, and so on. Therefore, understanding this complexity is important to understanding soil structure.
