SOIL FREEZING - THE CONCEPT OF SOIL-WATER POTENTIAL - STATE-OF-THE-ART

Soils and other porous media influenced by subzero temperatures impose special conditions an the water freezing within them. These condition s have been investigated by many scientists but they have only been de scribed in detail for the last three decades. The coexistence of ice a nd water in the soil pores is the most fundamental property of frozen soils. Consequently, the study of frozen soils requires consideration of phase change and freezing points. These conditions are very complex and the proper interpretation of field situations by means of the fun damental sciences, requires a careful attention to identifying the ter ms and concepts used by physicists and chemists with those used by geo logists, engineers, soil scientists and others. The author's aim is to present the review of different terms used for describing the process of water migration to the freezing zone. This effect is generally kno wn as a suction or cryosuction. In the following sections, a short lit erature review and a discussion of the concept of potential of soil wa ter is presented. understanding of the potential concept as applied to soils ia an introduction to understanding the water relations in soil freezing.