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

Ubiquistic substance

Sens commun

Persistent, bioaccumulative and toxic substance, or considered, at an equivalent level, as questionable.

Source

According to the Ministry for the Environment

Ultrafiltration

Sens technique

Filtration process on synthetic membranes, mineral or organic, between microfiltration and nanofiltration, i.e. between 0.01 and 0.1µm.

Source

according to OiEau

Unconfined aquifer

Sens technique

Aquifer with a free surface and unsaturated zone.

Source

According to Poitou-Charentes Regional Council

Unconfined groundwater

Sens technique

Volume of groundwater whose surface is free, i.e. at atmospheric pressure. The surface of an unconfined groundwater fluctuates freely without any constraint. These aquifers are often shallow.

Source

According to BRGM

A groundwater impoundment structure built across underground water channels. The underground dams are built in the sub-soil. They store water in geological formations, retain groundwater and require pumping facilities to make water usable.

Source

according to the Japanese Ministry of the Environment

Underground disposal

Sens commun

Discharge of effluents or pollutants on the ground or infiltration into the subsoil.

Source

according to the Ministry of the Environment and BRGM

Underground river

Sens commun

Stream passing through a very large cavity (e.g. a cave or a cavern) or a set of large communicating cavities.

Source

according to UNESCO

Unified Modelling Language

Sens technique

UML is a standard notation for modelling professional data.

Source

According to OFB and IOWater

Unsaturated zone

Sens commun

Subsurface zone not completely saturated with water (coexistence of water and air in the interstices of the rock) above the surface of an unconfined aquifer and where flows are vertical.

Source

according to BRGM and OFB

Untreated wastewater/sewage

Sens commun

Wastewater discharged into the natural environment without any treatment.

Source

According to Eurostat

Untreated water

Sens commun

Surface or ground waters as they occur in the natural environment before being treated for use. These are untreated wastewaters.

Source

According to Poitou-Charentes Regional Council

Up-dating/up-grading

Sens technique

A mathematical operation that compares economic values spreading over time by adjusting the future value of a property to the current value. The update allows the analysis to take into account the costs or benefits that will materialize in the future. Note: The choice of an up-date rate (coefficient used to bring a future value back to a present value) has an influence on the result. In 2005, the General Planning Commission proposed revising the up-dating rate of public investments.

Source

According to the Ministry for the Environment and IOWater

Upstream

Sens commun

Part of a watercourse which, with respect to a given point, is located between this latter point and the watercourse hearwaters.

Source

According to Adour-Garonne Water Agency

Urban planning Document

Sens technique

Guidance document of legal value that allows scheduling urban planning in a given area (municipality, agglomeration). The two main documents are the Land Use Plan (POS) and the Master Plan for Urban Planning and Development (SDAU).

Source

According to the Ministry for the Environment

Urban Waste Water Treatment Directive

Sens technique

Directive 91/271/EEC of 21 May 1991 concerning urban waste water treatment. It concerns the collection, treatment and discharge of urban waste water and the treatment and discharge of waste water from certain industrial sectors. Its purpose is to protect the environment against the adverse effects of the above-mentioned wastewater discharges. For this purpose, it defines the obligations of local authorities regarding the collecting and treatment of urban waste water and the terms and procedures for agglomerations with more than 2,000 population equivalents. The municipalities involved must, in particular,:…

Source

According to the Ministry for the Environment and OFB

Urban wastewater

Sens commun

Domestic wastewater or a mixture of domestic sewage and industrial wastewater and/or runoff water.

Source

According to Eurostat

Urban wastewater collecting system

Sens commun

All facilities for the collecting and treatment of urban wastewater. These systems are often managed by public authorities or semi-public associations.

Source

According to Eurostat

Usable Agricultural Area

Sens commun

Surface including field crops, permanent grassland areas, permanent crops (vineyards, orchards, etc), fallow lands, family gardens and orchards. The usable agricultural area does not include the grounds of buildings and yards, moors and unproductive wastelands, poplar plantations, thickets, woods and forests of the farm, as well as non-agricultural areas.

Source

According to Poitou-Charentes Regional Council

Use restriction

Sens réglementaire

Exceeded limits lead to restrictions of use and water withdrawal, to cope with a shortage of water resources during low water periods. Restriction measures are defined locally by the prefects. Generally, measures to limit withdrawals are progressive (depending on the thresholds defined for vigilance, alert, quick reaction alert or crisis) and adapted to different uses (domestic, agricultural, industrial).

Source

according to the Ministry of the Environment

Useful flood flow

Sens technique

Flood flows essential to the life of the watercourse and its water dependent areas, and having no unacceptable effects (especially on living settlements). Small floods have a fundamental role in the dynamics of environmental recovery, they should not be removed nor the environments be protected from them.

Source

According to the Ministry for the Environment and OFB

Utilization value

Sens technique

Value assigned to a good or service by an agent on the basis of the usefulness he derives from it. The utilization value involves two components: the actual utilization value and the option value attached to a possible use later on.

Source

According to Rhone-Mediterranean and Corsica Water Agency

UV absorbance

Sens technique

Optical measurement method (at 254 nm) for the evaluation of organic matter (mostly in aromatic form). Practical, but certain mineral elements represent a source of interference. Value to be correlated with that of TOC.

Source

according to OiEau