Glossaire de A à Z | Glossaire eau, milieu marin et biodiversité

Valley

Sens commun

Elongated and more or less flared depression dug by a stream or a glacier.

Source

according to the Larousse dictionary

Valve/Gate

Sens commun

Movable device for stopping or leaving free passage to water. For example: gates are used by dams or locks, valves in hydropower plants.

Source

according to the Larousse dictionary

Variable

Sens commun

Observed or measured characteristic - qualitative or quantitative - likely to vary in time and/or space. The notion of variable includes reference to an established protocol

Source

from ONB

Part of the cost of production which varies with the level of production. For example, the purchase costs of raw materials are variable costs that increase when the volume of activity or production increases.

Source

According to OFB

Vegetated discharge area

Sens technique

Space developed between the wastewater treatment plant and the receiving environment of treated wastewater discharges (it is not part of the wastewater treatment plant). The vegetated discharge areas (VDA) are characterised by the use of plants (mostly aquatic but possibly also terrestrial) and their planting close to the treatment plant, in the space remaining after the building of this plant. The VDA is not a wetland as there is no "long presence of natural water". It is also not a grass strip, specific to the mitigation of non-point source pollution (pesticides, fertilisers, sediments, etc.), especially in agriculture.

Source

according to OFB and IRSTEA

Vertebrate

Viaduct

Sens commun

Large road or rail bridge, usually consisting of several bays and crossing at high elevation a valley.

Source

according to the National Centre for Textual and Lexical Resour

Virtual water – see water footprint

Viscosity

Sens technique

A physical characteristic of water that can be defined as the resistance to uniform, turbulence-free flow occurring in the mass of a material.

As viscosity increases, the fluid's ability to flow decreases. For a liquid, viscosity generally tends to increase with decreasing temperature.

Source

according to OiEau

Volume distributed

Sens réglementaire

The volume distributed is the sum of the volume produced and the volume purchased wholesale (imported), minus the volume sold wholesale (exported).

CIRCULAIRE N° 12/DE DU 28 AVRIL 2008 - ANNEXE IV

Source

d'après Legifrance

Volume produced

Sens réglementaire

The volume produced is the volume generated by the service's production facilities to be fed into the distribution network. The service volumes of the production unit are not included in the volume produced.

CIRCULAIRE N° 12/DE DU 28 AVRIL 2008 - ANNEXE IV

Source

d'après Legifrance

Volume purchased in bulk (or purchased from other drinking water services)

Sens réglementaire

The volume purchased in bulk is the volume of drinking water supplied by an external water service. It is strictly equal to the volume imported.

CIRCULAIRE N° 12/DE DU 28 AVRIL 2008 - ANNEXE IV

Source

d'après Legifrance

Volume sold wholesale (or sold to other drinking water services)

Sens réglementaire

The volume sold wholesale is the volume of drinking water delivered to an external water service. It is strictly equal to the volume exported. Water sales to industrial customers are not wholesale sales, but sales to industrial subscribers.

CIRCULAIRE N° 12/DE DU 28 AVRIL 2008 - ANNEXE IV

Source

d'après Legifrance

Vulnerability

Sens technique

Fragility and susceptibility when facing a given hazard or a given pressure.

Source

According to SOeS

Vulnerable area

Sens technique

According to the Directive 91/676/EEC of 12 December 1991 called "nitrates", it means an area designated as vulnerable especially considering the characteristics of land and water as well as all available data on the nitrate concentration in water. Areas that feed waters are defined as: either affected by pollution (groundwater and surface freshwaters, especially those used for the abstraction of water intended for human consumption, whose nitrate concentration exceeds 50 milligrams per litre, and estuarine, coastal and marine waters and surface freshwaters which have undergone

Source

According to OFB

Vulnerable species

Sens commun

Species whose entry into the category of endangered species is considered likely in the near future in case of persistent factors that are the cause of the threat.

Source

According to the Ministry for the Environment and OFB