Hydrodynamics in soil

The movement of water in the subsurface, “Hydrodynamics,” touches many areas of the natural and human-influenced world. Ecosystems are shaped, contaminants spread, valleys flood, and slopes fail, all under the influence of hydrodynamic processes. These processes can be divided into four main subtopics based on whether flow is constant or changing in time and on whether the pores are or are not entirely filled with water. While these conditions share underlying concepts, there are specific considerations that make each unique.