Hydrogeology is a science that examines groundwater (from hydro, water, and geology, the study of the earth). It is also known as groundwater hydrology and, less commonly, Geohydrology. The main subject of study is geology and hydrology, but it also includes geostatistics, physics, chemistry, biology, geochemistry, hydrochemistry, geophysics, hydrodynamics, subsurface hydraulics, numerical analysis, and modeling approaches. As a result, hydrogeologique is an interdisciplinary science par excellence.

Hydrogeology is the study of groundwater distribution and circulation in soil and rocks, as well as its interactions with geological conditions and surface water.

Comparison of Hydrogeology to other branches

Hydrogeology, like the majority of earth sciences, is a multidisciplinary field. Although the basic principles of hydrogeology are self-evident (water flows downward, for example), analyzing their interactions can be quite difficult. In general, taking into account the interactions of many facets of a system with multiple components necessitates knowledge in a variety of experimental and theoretical branches.

The flow of groundwater in aquifers and other shallow porous media is the subject of hydrogeology, a branch of earth sciences. Soil science, agriculture, civil engineering, and hydrology all have an interest in the flow of very shallow water. For geology, geophysics, and petroleum geology, the flow of fluids present in deeper formations (such as water, but also carbohydrates and geothermal fluids) is crucial.

Groundwater is a viscous, slow-moving fluid (except near special geological environments such as karst conduits traversed by underground rivers, very coarse alluvium, and rocks). Many principles determined empirically from groundwater can also be deduced from fluid mechanics in the case of Stokes flow, when viscosity and pressure terms are considered rather than inertia.

Properties

An aquifer, as opposed to an aquitard or an aquiclude, which are both low permeability, is a permeable geological feature that holds and transports water. Aquitard is a term used to describe a geological formation having poor permeability. It is important to remember that for geological formations, permeability is relative. When compared to clay levels, sandstone can be called permeable, but when compared to coarse gravelly layers, it becomes less permeable.

The flow of groundwater can be restricted or unrestricted. In such an instance, the level of the groundwater flow’s free surface can move vertically without restriction upward. In the first situation, the presence of a low permeability level prevents the free surface level from being raised. The hydraulic potential at the free surface of the flow is equal to the altitude of this location in free flow. The hydraulic potential of a confined flow is larger than or equal to the elevation of the wall of the poorly permeable rock above the flow.