Soil hydrology: Stages of development, current state, and nearest prospects

Abstract

The main stages of the development of soil hydrology are described. These are: (1) the stage of classical hydrology based on the concepts of soil water forms and soil hydrological constants; (2) the stage of thermodynamic approaches toward assessing the statics and dynamics of soil water (soil hydrophysics); and (3) the modern stage of diverse approaches taking into account the specificity of water movement in a heterogeneous pore space (the development of preferential water flows), the specificity of the hydrological properties of soils in dependence on the scale of their examination, and the impact of the living soil phase on the soil hydrological processes. The diversity of modern approaches toward soil hydrology is reflected in the names of new branches of this science, such as hydropedology, geohydrology, biohydrology, etc. At the modern stage, all the conceptual approaches typical of the earlier stages of the development of soil hydrology are also applied. At present, soil hydrology is an actively developing field of soil science with clearly understood limits of application, advantages, and disadvantages of the methods typical of the first two stages. On this basis, an integral quantitative multilevel concept of soil hydrology is being developed.