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

Observation data

Sens technique

Data relating to a quality element or a parameter, produced by a control operation.

Source

According to OFB

Obstacle to flow

Sens commun

Any object or event obstructing the natural flow of a river. Obstacle to flow includes dams, sills, locks, etc, that affect the flow of water.

Source

According to OFB and IOWater

According to the hydrological meaning, a thin water layer that covers part of the Earth. In the geophysical sense, it means the areas where this water layer of several kilometres thick covers grounds where the crust is composed of basalt or related materials and not of continental materials (granites, etc). Therefore shelf seas or epicontinental seas are not part of the ocean in the geophysical sense.

Source

According to Ifremer

Oceanic current

Sens commun

Imagery of the movement of ocean water generated by the effect of the rotation of the Earth. Some currents move on the surface, when the transported water is hot (as in the "Gulf Stream" in particular), or deep, when water is cold (e.g. the "Arctic and Antarctic" currents).

Source

According to Ifremer

Oceanography

Sens commun

Study of the marine environment and ocean floor.

Source

according to the National Centre for Textual and Lexical Resour

Oligo-mesohaline lagoon

Sens technique

Lagune dont la salinité moyenne annuelle est située entre 0,5 et 5 PSU (oligo) et entre 5 - 18 PSU (méso).

Source

d'après OFB et Ifremer

oligochaete

Sens commun

Sediment-dwelling worm used to determine sediment quality or even the environmental contamination of the medium by micro-pollutants.

Source

According to Rhine-Meuse Water Agency

On-site sanitation

Sens commun

All treatment processes that remove wastewater from an individual single-family home usually on the plot on which the house is built, without any wastewater conveyance. An extension (rarer) concerns the wastewater treatment of some neighbouring houses on private land. It is still on-site sanitation but it is regrouped. On the contrary, a group having a small collecting system and a treatment facility (spreading, filters, etc.) on community land is considered community sanitation. On-site sanitation is first defined as opposed to community sanitation.

Source

According to the Ministry for the Environment and OFB

Open data

Sens technique

Refers to a process that aims to make truly re-usable the data generated by an organization, allowing their free and open reuse by proposing them in formats that facilitate reuse.

Source

According to OFB

Open sea

Sens commun

Part of the sea where there is no more land marker.

Source

According to Ifremer

Operational monitoring

Sens technique

Control to establish, as part of the water status monitoring programme, the status of water bodies which are not fully guaranteed to achieve their environmental objectives, and assess the effectiveness of programmes of measures on them.

Source

According to OFB

Operator of a classified facility

Sens réglementaire

Any individual or entity that operates a classified facility (holder of the authorization order), as well as the person who has or has been granted decisive economic power over it, in accordance with Law No. 76/663 of 19 July 1976 and

Source

According to BRGM

Opportunity cost

Sens technique

Value of lost opportunities due to the choice of the resource allocation to an activity rather than to another when the resource is scarce. In the field of water, e.g. the value of irrigated maize (UK) / corn (US) that could be produced by the water of a stream if the latter was not used for the production of drinking water or hydropower.

Source

According to the Ministry for the Environment and OFB

Option value

Sens technique

Use value given to the conservation of an asset for future use.

Source

According to the Ministry for the Environment

Order

Sens commun

Administrative decision of general interest (e.g. ministerial order of 29 February 1992 laying down a number of rules for all cattle farms subject to authorization) or individual (e.g. Prefect's order setting out the specific rules that the classified facility operated by Mr. X must comply with). Orders can be issued by ministers (ministerial or inter-ministerial orders), prefects (prefectural or prefect's orders) or mayors (municipal orders). The

Source

According to Rhone-Mediterranean and Corsica Water Agency

Ordonate

Sens commun

Insects with incomplete metamorphoses, with aquatic larvae, such as dragonflies and damselflies.

Source

according to Larousse dictionary

Sens technique

Order of hemimetabolic insects, terrestrial in the adult state, aquatic in the larval state, known under the name of Dragonflies or Damselflies, and whose adults are characterised by a large and mobile head, bearing very developed compound eyes, very short and filiform antennae, a crushing type mouth apparatus, by small and weak legs used mainly for gripping prey, by very large, membranous, hyaline or coloured wings, with a tight network of small veins which, at rest, are held vertical or oblique behind (Zygoptera) or arranged more or less horizontally (Anisoptera)

Source

according to CNRTL

Organic farming

Sens commun

Un Label. Méthode de production agricole excluant le recours aux produits chimiques de synthèse utilisés par l’agriculture industrielle et intensive. Les agriculteurs labellisés « bio » sont regroupés en fédérations avec des cahiers des charges à respecter. Ces derniers comprennent en général l’utilisation d’engrais d’origine naturelle, l’interdiction d’intrants d’origine chimique, la rotation des cultures et des élevages peu intensifs de manière à préserver les sols.

Source

d'après la Cité de l'agriculture

Organic matter

Sens commun

Matter generated by living beings (plants, animals, mushrooms and other decomposers including micro-organisms).

Source

according to Wikipedia

Organic micropollutant

Sens commun

Organic active ingredient, usually synthesized by the chemical industry, whose accumulation, even at low concentrations, can be toxic. The main organic micropollutants controlled are volatile organic compounds (VOC), hydrocarbons, andpolychlorinated biphenyl(PCB).

Source

According to Seine-Normandie Water Agency

Orphan site

Sens technique

Polluted site for which the people responsible of the pollution are either not identified or found, or either insolvent or refuse to meet their responsibilities.

Source

According to the Ministry for the Environment and OFB

Oslo Convention

Sens technique

International Convention signed in 1972 for the prevention of marine pollution by dumping from ships and aircraft. The Oslo Commission was responsible for administering the Oslo Convention; in 1992, it combined with the Paris Commission, before the new Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR Convention) entered into force in 1998.

Source

according to OSPAR Commission

Osmosis

Sens technique

Natural diffusion of a solvent through a semi-permeable membrane from a dilute solution to a concentrated solution. The difference in concentration creates a pressure known as osmotic pressure, the effect of which is to equalise the concentrations on either side of the membrane, and consequently to dilute the more concentrated solution. Osmosis plays a key role in the circulation of water in living organisms.

Source

according to OiEau

OSPAR Convention

Sens technique

Convention, signed in 1992, guiding international cooperation on the protection of the marine environment of the North-East Atlantic. It brought together and updated the 1972 Oslo Convention on dumping of waste at sea and the 1974 Paris Convention on marine pollution from land-based sources.

Source

According to the Ministry for the Environment

Outcrop

Sens commun

Part of a geological layer visible on the surface.

Source

According to the Ministry of Ecology

Outlet

Sens commun

Stream which discharges to the downstream part of a river basin the waters of a lake or of any other wetland.

Source

According to OFB

Outstanding area

Sens technique

An environment to be considered at the highest degree in an (international, national, basin, local) ranking scale because of its patrimonial, ecological value. The notion of ranking with the "outstanding" term introduces concepts of value.

Source

According to the Ministry of Ecology

Overfishing

Sens commun

Action of fishing too much of the natural production of a particular marine product.

Source

According to Ifremer

Oxbow lake

Sens commun

Part of an old meander or braid of a river. Oxbow lakes are more or less disconnected from the main channel due to the latter's displacement over time and to sedimentation mechanisms. Depending on their age, season and weather context, oxbow lakes can be with water or dry. These very rich evolutionary environments are favourable for breeding fish and some amphibians.

Source

According to OFB

Oxidation

Sens technique

Chemical reaction based on an exchange of electrons between the compound to be eliminated and the injected agent (chlorine, ozone, chlorine dioxide, potassium permanganate), the objective being to obtain an oxidised compound that is either more easily eliminated or less or non-toxic. However, certain reactions sometimes generate more troublesome or dangerous oxidised compounds. The position in the process and the choice of reagent is therefore variable and must be studied on a case-by-case basis.

Source

according to OiEau

Oxidizable material

Sens commun

Carbonaceous or nitrogenous organic matter (substance of biological origin). Oxidizable materials constitute the bulk of the biodegradable portion of the discharged organic pollution. The bacteria found in the medium use…

Source

According to Adour-Garonne Water Agency

Oyster farming

Sens commun

Traditional breeding of oysters.

Source

According to Poitou-Charentes Regional Council