Stagnant water
Définition
Sens commun
Still water in parts of a river, lake or other aquatic environment.
Source
according to UNESCO
Hydrology
Dam release
Définition
Sens technique
Operation to lower water level and increase outflow rates to discharge some of the sediment retained by a dam. A dam release consists in opening the gates, thus limiting the silting of the dam reservoir and the risk of flooding. This operation, although common in the management of harnessed rivers, can have adverse effects on the downstream environment (decrease of oxygen levels in water, obstruction of fish gills by suspended solids, etc.).
Source
according to ISTREA
Hydrological balance
Définition
Sens technique
Accounting of the changes in water resources (stream flows, groundwater level, effective rainfall) of an area (for example a catchment area) based on meteorological, piezometric or hydrological information.
Source
according to OFB
Water balance
Définition
Sens technique
Ratio between inflows to (e.g. precipitation, runoff, capillary rise) and outflows (e.g. transpiration or evaporation) from a given system over a given time interval, which gives the variation in water storage. The water balance allows knowing the soil water storage capacity, potentially usable for different purposes (agriculture or other).
Source
according to INRA and Aquitaine Chamber of Agriculture
Abstraction supply zones
Définition
Sens technique
Area on which the water that soaks into the ground supplies the abstraction for drinking water.
Source
According to the Ministry for the Environment and the Ministry for the Agriculture
Water abstraction
Définition
Sens commun
Extraction of fresh water from a groundwater source or surface, permanently or temporarily, and conveyed to the place of use. Water abstractions include all activities related levies generated by agriculture, industry (including energy), the supply of drinking water, or other (mineral spring authorized, production artificial snow).
Source
according to OFB, IOWater, SOeS and OCDE
Flow rate or flow or discharge
Définition
Sens technique
Volume of water passing through a cross section of a watercourse per time unit. The flow rates of watercourses are expressed in m3/s with at least three significant figures (e.g. 1.92 m3/s, 19.2 m3/s, 192 m3/s) or, for small streams in l/s. The accuracy of a flow result depends on many factors: type of method used, careful measures, rigorous counting, influence of the ground. In hydrology, the term "flow rate or flow" is found in many expressions having a descriptive character: low water flow, fluid flow, morphogenetic flow, solid discharge rate or
Source
Catchment area
Définition
Sens technique
Surface area feeding a watercourse or a body of water. The catchment area is defined as the area of water collecting up to an outlet: it is limited by a border within which all waters flow on the surface and underground to this outlet. Its boundaries are the watersheds (water divide - US).
Source
According to OFB
River basin (UK)
Définition
Sens technique
According to the Carthage database repository, a large catchment area (river basin) divided into several hydrographic regions, themselves divided into hydrographic sectors, hydrographic subsectors and hydrographic areas.Source
According to OFB and IOWater