Hydrology

The branch of meteorology that characterises the humidity of the air, i.e. the amount of water in gaseous form present in moist air (or in some other gas, in some industrial applications). Hygrometry does not take into account water present in liquid or solid form.

Science that aims to measure the physical properties of water, especially the flow of surface water and groundwater.

Branch of hydraulics relating to flows in areas with steep slopes.

A branch of hydraulics that mathematically studies the natural gravity flow (of an aquifer) or the induced flow (by drainage or pumping, for example) of free groundwater in permeable media, under the effect of a hydraulic or pressure gradient.

A branch of hydraulics related to the marine and coastal environments, which deals with swells, currents, dispersion and water quality, sedimentology, seaworthiness and the keeping of ships at station, or the interaction between waves and structures.

Branch of Hydraulics which mainly deals with the free surface flow of water in natural or artificial streams (e.g. canals). River hydraulics is necessary for the design, development and construction of hydraulic structures, such as dikes, sills and weirs.

A branch of fluid mechanics that deals with the flow of water (or other liquids) through pipes, open channels and other structures.

Transformation of snow into liquid water.

Deposit of fine sediments made of rock particles and silt or clay. Siltation is a form of sedimentation with mud. Streams carry a few million cubic meters of sediment each year. Their deposit causes the silting of these rivers, canals, and bodies of water. This quite natural phenomenon is accentuated by a flat topography, low flows, erosion processes, as well as industrial and urban discharges.