| EN | Definition | FR | NL |
|---|---|---|---|
| absorption | Measure of a surface's capacity to absorb incident energy, often at well-defined wavelengths. | absorption | absorptie |
| active sedimentary basins | Basin where the processes of sedimentation and tectonic deformations are presently active. It is characterised by the presence of active faults and earthquakes. | bassin de sédimentation active | actief sedimentair bekken |
| additive synthesis | Method of producing full-color images by mixing light of the three primary color wavelengths, blue, green and red. | additive synthesis | additive synthesis |
| aeolian | Caused by wind; refers to the erosion, transportation, and deposition of materials. Such processes tend to operate more efficiently in arid and semi-arid climates | éolien | eolisch |
| aerial photography | Photography from airborne platforms. | photographies aériennes | luchtfotografie |
| aerodynamic diameters | As particles are often non-spherical (for example, asbestos fibers), there are many definitions of particle size. The most widely used definition is the aerodynamic diameter. A particle with an aerodynamic diameter of 10 µm moves in a gas like a sphere of unit density (1 g/cm³) with a diameter of 10 µm. | aerodynamic diameters | aerodynamic diameters |
| aerosol | Colloidal system, such as a mist in which the dispersion medium is a gas. | aerosol | aerosol |
| Agenda21 | A dynamic UN programme of specific objectives and actions for a "new global partnership for sustainable development". | Agenda21 | Agenda21 |
| algorithm | Chronologic series of different formulas and/or simple calculation procedures in order to obtain results from data. | algorithm | algorithm |
| alluvium | Unconsolidated material transported and then deposited by flowing streams or river water in a riverbed, a flood plain, or a delta. | alluvium | alluvium |
| andesite | A fine-grained, frequently porphyritic, igneous rock. Phenocrysts are plagioclase feldspars with biotite, pyroxene and/or hornblende. The groundmass has essentially the same mineralogy as the phenocrysts. | andesite | andesite |
| anomaly | Irregularity, deviation from a standard situation. | anomaly | anomaly |
| anthropogenic | Originating from the activity of humans. | anthropogenic | anthropogenic |
| arctic | Extended area near the North Pole delimited by the arctic polar circle. | arctique | arctisch |
| arid | Climate or habitat with less than 250 mm annual rainfall, very high evaporation and sparse vegetation | arid | arid |
| artefact | Artificial phenomenon found during an observation or an experiment. | artefact | artefact |
| attribute | In GIS geomatric attributes define the three-dimensional localisation of a phenomenon while thematic attributes define the thematic characteristics of the localised phenomena. | attribute | attribute |
| autotrophic respiration | The process by which an organism utilizes carbon dioxide as a source of carbon and obtain their energy from the sun or by oxidizing inorganic substances such as sulphur, hydrogen, ammonium, and nitrate salts. | autotrophic respiration | autotrophic respiration |
| backscatter | The portion of the out-going radar signal that the target redirects directly back towards the radar antenna. If the signal formed by backscatter is undesired, it is called "clutter". Other portions of the incident radar energy may be reflected or absorbed or scattered away from the radar. | backscatter | backscatter |
| basalt | A fine-grained basic igneous rock. The essential minerals of basalt are anorthite-rich plagioclase, feldspar and augite. It is typically found as a lava flow. | basalt | basalt |
| bathymetry | Measurement of the depth of large bodies of water using different techniques. | bathymetry | bathymetry |
| biodiversity | The biological diversity of an area as a function of the amounts of animal or plant species present, their uniqueness and specifivity, and the number of individuals of each species. | biodiversity | biodiversity |
| biomass | Total mass of living organic matter (plants, animals, micro-organisms) present in a habitat. | biomass | biomass |
| black body | In physics, a surface that absorbs all radiant energy falling on it. The term arises because incident visible light will be absorbed rather than reflected, and therefore the surface will appear black. The concept of such a perfect absorber of energy is extremely useful in the study of radiation phenomena. | corps noir | zwart lichaam |
| block diagram | Three-dimensional model of a part of the terrestrial surface representing its topographic surface. The model allows to reproduce phenomena on the surface (e.g. land use) or under the surface (e.g. geological structure). Block diagrams are also used to visualise socio-economic or physical phenomena in the z-dimension (height) of the diagram. | block diagram | block diagram |
| buffering | A spatial analysis or map algebra function that creates an extension zone around a point, line or polygon by locating its boundaries at a user-defined distance from it. | buffering | buffering |
| Byte | Several (usually eight) binary bits of data grouped together to represent a character, digit, or other value. | Byte | Byte |
| canyon | A narrow chasm with steep cliff walls, cut into the earth by running water; a gorge. | canyon | canyon |
| carbon balance | The balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g. atmosphere/ biosphere) of the carbon cycle. | bilan carbone | koolstofbalans |
| carrying capacity | Represents the maximal number of a species that a biotope can support without a risk for its survival. | capacité d'accueil | draagkracht |
| cartography | The science of representing as accurately as possible the earth's surface of parts of it on a flat or spherical surface. Cartography also studies methods for the representation on a flat surface of the features of a curved surface. | cartography | cartography |
| catchment area | Area determined by topographic features within which falling rain will contribute to runoff to a particular point under consideration. The area tributary to a lake, stream, sewer or drain. | catchment area | catchment area |
| centrifugal force | The component of apparent force on a body in curvilinear motion, as observed from that body, that is directed away from the center of curvature or axis of rotation. The opposite is a centripetal force. | centrifugal force | centrifugal force |
| CFC | Chlorofluorocarbon. A family of compounds of chlorine, fluorine, and carbon, entirely of industrial origin. CFCs include refrigerants, propellants for spray cans and for blowing plastic-foam insulation, styrofoam packaging, and solvents for cleaning electronic circuit boards. The compounds' lifetimes vary over a wide range, exceeding 100 years in some cases. CFCs' ability to destroy stratospheric ozone through catalytic cycles is contributing to the depletion of ozone worldwide. Into the stratosphere, the molecules are bombarded by ultraviolet rays, causing the CFCs to break up and release their chlorine atoms, which participate in ozone destruction (a single atom of chlorine is able to destroy ozone molecules over and over again). Since 1989 the use of CFC's was limited. | CFC | CFK |
| CFC (chlorofluorocarbon) | A family of compounds of chlorine, fluorine, and carbon, entirely of industrial origin. CFCs include refrigerants, propellants for spray cans and for blowing plastic-foam insulation, styrofoam packaging, and solvents for cleaning electronic circuit boards. The compounds' lifetimes vary over a wide range, exceeding 100 years in some cases. CFCs' ability to destroy stratospheric ozone through catalytic cycles is contributing to the depletion of ozone worldwide. Into the stratosphere, the molecules are bombarded by ultraviolet rays, causing the CFCs to break up and release their chlorine atoms, which participate in ozone destruction (a single atom of chlorine is able to destroy ozone molecules over and over again). Since 1989 the use of CFC's was limited. | CFC (chlorofluorocarbon) | CFC (chlorofluorocarbon) |
| chert | SiO2, an opaque chalcedony that is bedded and massive, fractures in a conchoidal fashion and is generally dull grey-black in colour. | chert | chert |
| chlorophyll | Green plant pigment, synthetizised in the chloroplasts in the presence of light and playing a essential role in the photosynthesis. | chlorophyll | chlorophyll |
| classification | Grouping image pixels into categories or classes to produce a thematic representation. | classification | classification |
| climate change | A change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods. This term is commonly used interchangeably with "global warming" and the "greenhouse effect", but is a more descriptive term. Climate change refers to the buildup of man-made gases in the atmosphere that trap the suns heat, causing changes in weather patterns. | changements climatiques | klimaatsveranderingen |
| Climatic efficiency | Proportion of PAR (photosynthetically active radiation) over total radiation. | efficacité climatologique | klimatologische efficiëntie |
| coherence | Property of a signal or data set in which the phases of the constituents are statistically correlated, or systematically related. | cohérence | coherentie |
| colour composite | A colour image produced through optical combination of multiband images by assigning the three primary colours (blue, green and red) to three selected channels of an image. | composition colorée | kleurencomposiet |
| contrast enhancement | A radiometric enhancement technique used to improve the visual contrast of an image. It matches the data's dynamic range to the dynamic range of the display medium (photographic or digital). | contrast enhancement | contrast enhancement |
| coordinates system | System to localise each point at the Earth's surface using units of choice. The latitude, longitude en altitude correspond to a position on the Earth's surface, The system accounts for the dimensions and the shape of the Earth. | coordinates system | coordinates system |
| Corine | The Corine programme of the EU had three objectives: - collecting information on the environment in priority domains, - coordonnate the efforts to gather and organise data on the level of the member states or on international level, - guarantee the coherence of the information and assure the recording of the data. | Corine | Corine |
| correlation | A relation existing between phenomena or things or between mathematical or statistical variables which tend to vary, be associated, or occur together in a way not expected on the basis of chance alone. | correlation | correlation |
| crop growth model | Model based on data on crops, soils and management practices which can help farmer predict crop growth and yield. | modèle de croissance des cultures | gewasgroeimodel |
| cynegetics | Relative to hunting and game. | cynégétique | cynegetica |
| database | Any collection of information on a specific subject or area. Specifically, a computerized collection of such information. | banque de données | gegevensbank |
| desertification | The gradual enlargement and encroachment of deserts into formerly marginal arid lands, caused by climatic factors such as prolonged drought and by overgrazing and overcultivation. | desertification | desertification |
| diachronic | Phenomenon whereby a layer with a constant facies [characterising appearance or composition of a rock or stratified body] varies in age from place to place. | diachronique | diachroon |
| digital | -format. Opposite of analog format. Used for data coded in a discrete, numerical format. | digital | digitaal |
| Digital Elevation Model | (DEM) A geographic grid of an area where the contents of each grid cell represents the height of the terrain in that cell. Buildings, trees or other features on the ground are not included in the elevation values. In most cases used synonymously with DTM (Digital Terrain Model). | Modèle numérique d’élévation | Digitaal Hoogtemodel |
| Digital Elevation Model (DEM) | Digital Elevation Model - a geographic grid of an area where the contents of each grid cell represents the height of the terrain in that cell. Consists of x, y and z coordinates. | Digital Elevation Model (DEM) | Digital Elevation Model (DEM) |
| digital format | Opposite of analog format. Used for data coded in a discrete, numerical format. | digital format | digital format |
| Digital Surface Model | (DSM) A geographic grid of an area where the contents of each grid cell represents the height of the ground plus all features on it (trees, buildings, ...) in that cell. |
Modèle numérique de surface | Digitaal oppervlaktemodel |
| Digital Terrain Model | (DTM) A geographic grid of an area where the contents of each grid cell represents the height of the terrain in that cell. Buildings, trees or other features on the ground are not included in the elevation values. In most cases used synonymously with DEM (Digital Elevation Model). | Modèle Numérique de Terrain | Digitaal Terreinmodel |
| Digital Terrain Model (DTM) | Description of a terrain using a set of x,y,z coordinates. X and y represent the geographical coordinates while z represents a third data, e.g. soil data, demographical data,… | Digital Terrain Model (DTM) | Digital Terrain Model (DTM) |
| digitise | Transformation of analogue data into numeric data (using a digitizing table). | digitise | digitise |
| Dobson unit | The standard way to express ozone amounts in the atmosphere. One DU is 2,7 x 10 -16 ozone molecules per square centimeter. One DU refers to a layer of ozone that would be 0.001 cm thick under conditions of standard temperature and pressure. | Dobson unit | Dobson unit |
| Ecology | Science dealing with the interrelationships between living organisms and their environments. | Ecology | Ecology |
| Economic Exclusion Zone | All marine waters from the outer edge of the Territorial Sea (12 nautical miles) seaward for 188 nautical miles until the 200 nautical mile limit. The EEZ refers to the rights of coastal states to control the living and nonliving resources of the sea for 200 miles off their coasts while allowing freedom of navigation to other states beyond 12 miles, as agreed at the sixth session of the Third U.N. Conference on the Law of the Sea (UNCLOS). The EEZ also gives the coastal states the responsibility for managing the conservation of all natural resources within the 200-mile limit. | Economic Exclusion Zone | Economic Exclusion Zone |
| ecosystem | The interacting system of a biological community and its non-living environmental surroundings. | ecosystem | ecosystem |
| erosion | The transportation of particles produced by weathering by a variety of agents including moving ice, flowing water, wind and mass movement. | érosion | erosie |
| escarpment | A steep slope created by erosion or faulting. | escarpement | steilrand |
| estuary | The point at which the mouth of a river enters the sea and freshwater and seawater are mixed; a place where tides ebb and flow. | estuaire | estuarium |
| eutrophication | Excessive enrichment of water with nutrients, momentarily or durably, notably linked to input of natural or synthetic fertilizers, which favours the growth of algues and other microscopic plants and results in a decrease of the water's oxygen content. | eutrophisation | eutrofiëring |
| extrapolate (extrapolation) | To predict by projecting past experience or known data. | extrapolate (extrapolation) | extrapolate (extrapolation) |
| extrapolation | Extrapolate: to predict by projecting past experience or known data. | extrapolation | extrapolatie |
| false colour composite | An image produced by displaying multiple spectral bands as colours different from the spectal range they were taken in. | composition fausses couleurs | valse kleuren composiet |
| fAPAR | Ratio of incident PAR-radaiation (Photosynthetic Active Radaiation) absorbed by vegetation. fAPAR represents the fraction of efficiency of absorbed PAR-radiation. | fAPAR | fAPAR |
| fault | A fracture in the continuity of a rock formation caused by a shifting or dislodging of the earth's crust, in which adjacent surfaces are differentially displaced parallel to the plane of fracture | fault | fault |
| feeding ground | Place where wild animals feed. The feeding ground may be artificial, i.e. created on purpose to feed the animals: food patches or improved meadows. | feeding ground | feeding ground |
| field of view | The area or solid angle which can be viewed through an optical instrument. | champ de visée | gezichtsveld |
| filter[ing] | A mathematical procedure which selectively modifies the values of numerical data. | filter[ing] | filter[ing] |
| filtering | A mathematical procedure which selectively modifies the values of numerical data. | filtrage | filteren |
| forest not under state control | Here used for the Walloon region 'Forêt non soumise': The total of forests not managed by the forestry administration of the Walloon Region. | forêt non soumise | Bos niet onder staatscontrole |
| forest under state control | Here used for the Walloon region 'Forêt soumise': The total of forests managed by the forestry administration of the Walloon Region. | forêt soumise | bos onder staatscontrole |
| fossil fuels | The ancient, altered remains of organisms that are extracted from the surface/near-surface parts of the Earth's crust and used as fuel; predominantly coal, natural gas and oil. They account for ca. 82% of the world's energy consumption. | combustibles fossiles | fossiele brandstoffen |
| fraction image | A fraction image is a map, resulting from a soft classification procedure, representing a single class (e.g. vegetation, water,..). Each pixel on this a map has been attributed a value ranging from 0 to 100 with 0 indicating that the class in question does not occur within the pixel, while a value of 100 means that no other class is present in the pixel. Mostly, the value is between those extremes. | image fractionnée | fractiebeeld |
| fuzzy logic | In mathematics, a form of logic based on the concept of the fuzzy set. Membership in fuzzy sets is expressed in probabilities or degrees of truth, i.e., as a continuum of values ranging from 0 to 1. | logique floue | vaagheidslogica |
| gallery forest | A forest growing along a watercourse in a region otherwise devoid of trees. | forêt galerie | galerijbos |
| geo-archaeology | Geo-archaeology is an area of specialization within archaeology. Geo-archaeologists focus on the interaction between artifacts, sites, and natural geological processes. | géo-archéologie | geo-archeologie |
| geocentric coordinates | The position of a locality relative to the Earth's centre of mass. | coordonnées géocentriques | geocentrische coördinaten |
| geocoding | The activity of defining the position of geographical objects relative to a standard reference grid. | géocodage | geocoderen |
| geodesy | Science studying the shape and the dimensions of the Earth. | géodésie | geodesie |
| geodetic datum | A geodetic datum is a reference object that describes the position, orientation and scale relationships of a reference ellipsoid to the Earth. A datum allows to define coordinates related to a well-defined reference frame. Modern geodetic datums are defined with respect to the center of the Earth, while historical geodetic datums are defined with respect to fundamental points on the surface of the Earth. | datum géodésique | geodetische datum |
| geodynamics | A branch of mechanics that deals with forces within the earth and their relation to the motion and equilibrium of the solid earth. | geodynamics | geodynamics |
| geographical coordinates | The position of a localit, given in terms of latitude and longitude, relative to the equator and the prime meridian. | coordonnées géographique | geografische coördinaten |
| Geographic Information System | A Geographic Information System (GIS) is a computerized tool designed for storing, analyzing and consulting data where geographic location is an important characteristic or critical to the analysis. It allows the mutual comparison of properly encoded spatial data, their combination with non-spatial information (e.g. statistical data) and their representation as a map. | Système d'information géographique | Geografisch Informatie Systeem |
| Geographic Information System (GIS) | A Geographic Information System is a computerized tool designed for storing, analyzing and consulting data where geographic location is an important characteristic or critical to the analysis. It allows the mutual comparison of properly encoded spatial data, their combination with non-spatial information (e.g. statistical data) and their representation as a map. | Geographic Information System (GIS) | Geographic Information System (GIS) |
| geographic reference system | (georeference). The process of establishing a relationship between data in Cartesian coordinates on a flat map to known ground-truth geographic coordinates. | système de référence géographique | geografisch referentiesysteem |
| geographic reference system [georeference] | The process of establishing a relationship between data in Cartesian coordinates on a flat map to known ground-truth geographic coordinates. | geographic reference system [georeference] | geographic reference system [georeference] |
| geology | The study of the earth forming materials and their transformations in the past and the present. | géologie | geologie |
| Geomatics | Field of activity which, using a systematic approach, integrates all the means used to acquire and manage spatial data required as part of scientific, administrative, legal and technical operations involved in the process of production and management of spatial information. | Geomatics | Geomatics |
| geometric correction | The removal of sensor, platform, or scene induced geometric errors such that the data conforms to a desired projection. This involves the creation of a new digital image by resampling the input digital image. | geometric correction | geometric correction |
| geometric corrections | The removal of sensor, platform, or scene induced geometric errors such that the data conforms to a desired projection. This involves the creation of a new digital image by resampling the input digital image. | corrections géométriques | geometrische correcties |
| Geomorphology | The study of the land surface features and the processes that created them. | géomorphologie | geomorfologie |
| georeferenced | Digital spatial data (and non-digital map features) for which the coordinates or location are determined. A georeferenced image is an image in wich the coordinates of each pixel are known. Georeferencing can be done using various cartographic projections. | georeferenced | georeferenced |
| geospatial map | Or satellite image map. Satellite image resampled in a cartographic projection, with the eventual addition of graphical elements, comments and legends, e.g. resulting from the interpretation of the image. | spatiocarte | satellietbeeldkaart |
| geostationary | A satellite orbit that stays in a fixed position relative to the surface of the Earth. Meteorological satellites usually follow a geosynchronous orbit. The satellite moves from west to east at a speed that allows it to remain over the same point on the Earth. | géostationnaire | geostationnair |
| Global Positioning System (GPS) | A network of satellites developed by the US Department of Defense. Using this system, the location of any site on the Earth's surface can be measured within several metres or centimeters (depending upon the system used). | Global Positioning System (GPS) | Global Positioning System (GPS) |
| GPS | Global Positioning System - A network of satellites developed by the US Department of Defense. Using this system, the location of any site on the Earth's surface can be measured within several metres or centimeters (depending upon the system used). | GPS | GPS |
| greenhouse effect | Process by which significant changes in the chemical composition of the Earth's atmosphere may enhance the natural process that warms our planete and elevates temperatures. | greenhouse effect | greenhouse effect |
| greenhouse gas | Gas capable of absorbing terrestrial radiation (i.e. radiation emitted by the earth). With respect to their influence on the climate, the main greenhouse gases are water vapour, carbon dioxide, methane, nitrous oxide and the wholly anthropogenic chlorofluorocarbons. | greenhouse gas | greenhouse gas |
| grid | A network of regularly spaced straight lines intersecting at right angles. The raster is thus composed of cells of the same size. Each cell is assigned an integer or decimal numeric value. This structure or format is used for representing geographic information in some GIS software packages. | grille | raster |
| grid cell | A discretely uniform unit that represents a portion of the Earth. such as a square meter or square mile. Each grid cell has a value that corresponds to the feature or characteristic at that site, such as a soil type, census tract, or vegetation class | cellule matricielle | rastercel |
| Ground Control Point | (GCP). Selected point referring to a certain location on the ground for which there is an accurate positional information (latitude, longitude). | point de contrôle au sol | grondcontrole punt |
| Ground Control Point (GCP) | Selected point referring to a certain location on the ground for which there is an accurate positional information (latitude, longitude). | Ground Control Point (GCP) | Ground Control Point (GCP) |
| ground station | Data collection, receiving or processing facilities located on the ground. | station de réception | grondstation |
| heterotrophic respiration | The energy producing process of breathing, by which an organism breaks down non-living organic matter and supplies its cells with oxygen and relieves itself of carbon dioxide. | heterotrophic respiration | heterotrophic respiration |
| histogram | A graphical means of expressing the frequency distribution of pixel values in a remote sensing image. The x-axis shows the range of brightness values in the image. The height of the vertical bars are proportional to the number of pixels in the image in each class. | histogram | histogram |
| hydraulic | Pertaining to hydraulics, or the study of the dynamics of fluids, particularly water. | Hydraulique | hydraulisch |
| Hydrology | Study of the mechanical, physical and chemical properties of oceanic and continental water. | Hydrologie | Hydrologie |
| Hydrometeorology | The science that combines hydrology and meteorology, with its main emphasis on the atmospheric sector of the hydrological cycle. | Hydrométéorologie | hydro-meteorologie |
| IHS-RGB fusion | Fusion of Intensity - Hue - Saturation and Red -Green - Blue. Method of displaying images. The IHS transformation is commonly used to merge several bands of remote sensed data, e.g. high resolution panchromatic images with low resolution multispectral images. A RGB-IHS transformation is executed on the multispectral image, the Intensity channel is replaced by the panchromatic image and the inverse transformation RGB - IHS is executed. The result is an image containing the spatial resolution of the panchromatic image and the colours of the multispectral image. | IHS-RGB fusion | IHS-RGB fusion |
| image fusion | Technique allowing to make an efficient synthesis of several information sources. There is a growing interest because of the growth in available data, particularly of remote sensed data. | image fusion | image fusion |
| in situ measurements | Field measurements. The measuring instrument is in (almost) direct contact with the object to measure. | in situ measurements | in situ measurements |
| interferometric coherence image | Image for which each pixelvalue gives the degree of correlation of two SAR images. | cohérence interférométrique | interferometrische coherentie beeld |
| interferometry | (or phasimetrie) Combination of measuring techniques based on the information regarding the phase in radar images. The SAR technique uses the difference in phase between SAR observations of the same scene taken from slightly differeent angles. The resulting interferogramme allows to detect small changes in the Earth's surface. | interférométrie | interferometrie |
| interpolation | The process or technique of obtaining an estimate of the value intermediate between given values. | interpolation | interpolatie |
| isotherm | Line connecting points of equal temperature. | isotherme | isotherm |
| kinetic energy | Energy of a body in motion. | énergie cinétique | kinetische energie |
| lahar | Word derived from Indonesian meaning mudflow. A lahar is made up of a dense and very erosive mixture of over 50% volcanic debris and water (from precipitation, snow or glaciers,…), which is chanelled down the volcano's drainage system. This phenomenon can affect valleys around the volcano for years after an eruption. | lahar | lahar |
| Lambert | French 18th century mathematician who defined several cartographic projections. In Belgium the conical Lambert projection is used. | Lambert | Lambert |
| landslide | An abrupt movement of soil and bedrock downhill in response to gravity. Landslides and rockslides may be initiated by heavy rains, earthquakes or by human activities. | landslide | landslide |
| lateral spread | The lateral stretching of coherent rock or soil over an underlying deformed mass of soft material. | écart latéral | laterale uitdijing |
| lava dome | A steep-sided mound that forms when viscous lava piles up near a volcanic vent. Domes are formed by andesite, dacite, and rhyolite lavas | lava dome | lava dome |
| Leaf Area Index | (LAI). The total one-sided green surface of foliage per unit of soil area. LAI is an important element in remote sensing. It is used to quantify numerous biological and physical processes such as primary production, plant respiration, transpiration, photosynthesis an nutrient cycles. It is likewise of use in the detection of burnt areas. | Indice de Surface Foliaire | bladoppervlak index |
| Leaf Area Index (LAI) | The total one-sided green surface of foliage per unit of soil area LAI is an important element in teledetection. It is used to quantify mumerous biological and physical processes such as primary production, plant respiration, transpiration, photosynthesis an nutrient cycles. It is likewise of use in the detection of burnt areas. | Leaf Area Index (LAI) | Leaf Area Index (LAI) |
| LiDAR | LiDAR, which stands for Light Detection and Ranging, is a remote sensing method that uses light (IR, visible or UV wavelengths) in the form of a pulsed laser to measure ranges (variable distances) to the Earth. The time needed for the light beam to reach the target and return to the transceiver is used to determine the distance between the two. The light pulses—combined with other data recorded by the airborne system— generate precise, three-dimensional information about the shape of the Earth and its surface characteristics. A LiDAR instrument principally consists of a laser, a scanner, and a specialized GPS receiver. | LiDAR | LiDAR |
| lineament | A linear (relatively straight) topographic feature or features such as a fault, line of dense vegetation, or a chain of aligned volcanoes. Can often be observed on satellite imagery. | linéament | lineament |
| liquefaction | The process in which a granular solid (soil) takes on the characteristics of a liquid as a result of an increase in pore pressure and a reduction in stress. In other words, solid ground looses cohesion and starts flowing like a liquid. | liquefaction | liquefaction |
| lithology | The study and description of the general, gross physical characteristics of a rock, especially sedimentary clastics, including color, grain size, and composition. | lithologie | lithologie |
| marl | Sedimentary rock composed of a mixture of chalck and clay. | marne | mergel |
| mask | Element used to cover or delimit a zone or an area on a graphic analog document or on an image document (photograph, satellite image, ...) | masque | masker |
| matrix | A rectangular array of numeric or algebraic quantities subject to mathematical operations. | matrice | matrix |
| Maximum Likelihood | Classification technique A statistical decision rule that examines the probability function of a pixel for each of the landcover classes, and assigns the pixel to the class with the highest probability. | Maximum Likelihood | Maximum Likelihood |
| metadatabase | Meta-data is definitional data that provides information about or documentation of other data managed within an application or environment. Meta data may include descriptive information about the context, quality and condition, or characteristics of the data. | métabase de données | meta-databank |
| meteogrid | Georeferenced grid for which each cell is attributed one or more measured or calculated meteorological data. | grille météo | meteoraster |
| monitoring | To watch, keep track of, or check periodically or continuously, usually for a special purpose. | monitoring | monitoring |
| morphology | Study of shapes and structures. Geomorphology studies the shapes in the relief. | morphologie | morfologie |
| mosaic | An assemblage of overlapping aerial or space photographs or images whose edges have been matched to form a continuous pictorial representation of a portion of the earth surface. | mosaïque | mozaiek |
| multidimensional approach | multidimensional approach | multidimensional approach | |
| multispectral | Containing two or more spectral bands. Multispectral data: set of data acquired simultaneously but in different areas of the electromagnetic spectrum. Multispectral analysis: study of data in various spectral bands. Multispectral imagery: two or more images acquired at the same time but in different areas of the electromagnetic spectrum. | multispectral | multispectral |
| multitemporal | Image - Colour composite, consisting of three images recorded at a different moment. | multitemporelle | multitemporeel |
| multitemporal change vector analysis | Analysis of change vectors, applied to multitemporal coverage imagery. The change vector compares for each pixel the difference in the time-trajectory of a biophysical indicator, such as the normalized difference vegetation index. | analyse vectorielle multitemporelle | multitemporal change vector analysis |
| multitemporal image | Colour composite, consisting of three images recorded at a different moment. | multitemporal image | multitemporal image |
| nadir-viewing | In Nadir Mode, the line of sight of a sensor points from the orbit downward to the Earth's surface or atmosphere. | observation nadir | nadir observatie |
| NDVI | The Normalized Difference Vegetation Index (NDVI) is a vegetation index and is calculated from atmospherically corrected reflectances from the visible red and near infrared channels. The resulting index value is sensitive to the presence of vegetation on the land surface. |
NDVI | NDVI |
| Neolithic revolution | Relating to the big changes in the human way of life in the Neolitic by using natural resources (fertile soil for agriculture, vegetation and in particular wood for fuel…), man attempts to use his environment to the fullest and settles down in small settlements or villages. | révolution néolithique | Neolithische revolutie |
| Neolitic | Historic period starting around 10,000 years ago in the Middle East. The period is characterised by the development of agriculture and the improvement of stone tools | Néolithique | Neolithicum |
| neotectonics | (neo-=new, recent) Science studying recent types of movements of the earthcrust and the earth layers, e.g. recent faults, foldings, overthrust,… | néotectonique | neotektoniek |
| NEP | Net Ecosytem Productivity, i.e. gross productivity minus autrotrophic and hetereotrophic respiration. | PNE (Productivité nette de l'écosystème) | NEP |
| Normalized Difference Vegetation Index | The Normalized Difference Vegetation Index (NDVI), is a vegetation index and is calculated from atmospherically corrected reflectances from the visible red and near infrared channels. The resulting index value is sensitive to the presence of vegetation on the land surface. | Indice de Végétation par Différence Normalisée | Normalised Difference Vegetation Index |
| NPP | Net Primary Productivity, i.e. gross photosynthesis or gross primary productivity minus autotrophic respiration. | PPN (Productivité primaire nette) | NPP |
| NUTS | Nomenclature of territorial units for statistics. In agreement with the other Commission departments concerned, Eurostat has drawn up a nomenclature of statistical territorial units (NUTS). The current NUTS nomenclature subdivides the territory of the European Community into `Country' (or 'NUTS 0') , 'Region' ('NUTS 1),.… | NUTS | NUTS |
| NUTS (Nomenclature of territorial units for statistics) | In agreement with the other Commission departments concerned, Eurostat has drawn up a nomenclature of statistical territorial units (NUTS). The current NUTS nomenclature subdivides the territory of the European Community into `Country' (or 'NUTS 0') , 'Region' ('NUTS 1),.… | NUTS (Nomenclature of territorial units for statistics) | NUTS (Nomenclature of territorial units for statistics) |
| occultation technique | Measuring stellar spectra in the UV to near-infrared range while stars are being ecplised by the Earth. | occultation technique | occultation technique |
| optic | (image, satellite, sensor). Optical system: A collection of mirrors, lens, prisms, and other devices (placed in some specified configuration) which reflect, refract, disperse, absorb, polarize, or otherwise act on light. Optical sensing: The science and techniques of using optical systems as sensors. Optical image: approximate replica of an object formed by focusing the waves that emanate from the object. The object may be self-luminescent, or it may reflect illumination from an additional source of waves. | optique | optisch |
| optic (image, satellite, sensor) | Optical system: A collection of mirrors, lens, prisms, and other devices (placed in some specified configuration) which reflect, refract, disperse, absorb, polarize, or otherwise act on light Optical sensing: The science and techniques of using optical systems as sensors Optical image: approximate replica of an object formed by focusing the waves that emanate from the object. The object may be self-luminescent, or it may reflect illumination from an additional source of waves. | optic (image, satellite, sensor) | optic (image, satellite, sensor) |
| orbit | The path described by a heavenly body in its periodic revolution. Earth satellite orbits with inclinations near 0° are called equatorial orbits because the satellite stays nearly over the equator. Orbits with inclinations near 90° are called polar orbits because the satellite crosses over (or nearly over) the north and south poles. | orbite | orbit |
| orbital angle | Or inclination. Angle between equatorial plan and the the satellite's orbital plane. | angle orbital | orbitale hoek |
| orbital angle / inclination | Angle between equatoral plan and the the satellite's orbital plane | orbital angle / inclination | orbital angle / inclination |
| orbital plane | An imaginary gigantic flat plate containing an Earth satellite's orbit. The orbital plane passes through the center of the Earth. | orbital plane | orbital plane |
| orography | Pertaining to the geography of mountains. | orography | orography |
| orthophoto map | A map produced from a mosaic of orthophotographs, to which has been added a grid, cartographic symbology and sometimes colour | orthophotoplan | orthofotoplan |
| orthorectification | Use of photogrammetric techniques to adjust and correct for terrain displacement in images. | orthorectification | orthorectification |
| ortophotograph | An oblique aerial photograph that has been rectified (corrected) to remove the displacement of points caused by camera tilt and terrain relief. | ortophotograph | ortophotograph |
| ozone | One of the several gases that make up the earth's atmosphere. It is the triatomic form of oxygen and makes up approximately one part in three million of all of the gases in the atmosphere. It is formed following the dissociation of oxygen molecules (O2) caused by the absortion of UV rays. While beneficial in the stratosphere, ozone in the troposphere is toxic for living organisms. | ozone | ozon |
| ozone layer | Part of the stratosphere: zone between the tropopause (altitude between 9000 km (poles) and 18,000 km (equator) and the stratopause (50,000 km). The ozone layer protects the earth with regard to UV radiation. Analyses demonstrate a seasonal variation over Antarctica. | couche d'ozone | ozonlaag |
| panchromatic | Sensitive to light of all colors in the visible spectrum. | panchromatique | panchromatisch |
| parallax | An apparent change in de orientation of an object, due to a change in the position of the observer. | parallaxe | parallax |
| phase shift | Difference in phase, expressed in radials, between two waves with the same frequency? | phase shift | phase shift |
| photogrammetry | The science of deriving the physical dimensions of objects from measurements on aerial photographs | photogrammetry | photogrammetry |
| photo-interpretation | The reading and interpretation of aerial photographs and images through the quantitative and qualitative analysis of colour, contrast, texture and tone by an experienced operator. | photo-interprétation | foto-interpretatie |
| photometer | An instrument used to measure the intensity of light over a selected range of the spectrum. | photometer | photometer |
| photosynthesis | The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll with sunlight as the energy source. Oxygen and water vapor are released in the process. Photosynthesis is dependent on favorable temperature and moisture conditions as well as on the atmospheric carbon dioxide concentration. | photosynthèse | fotosynthese |
| photosynthetically active radiation | (PAR); Those wavelengths in the spectrum of radiation that are effective in photosynthesis. | rayonnement photosynthétiquement actif | fotosynthetische actieve straling |
| photosynthetically active radiation (PAR) | Those wavelengths in the spectrum of radiation that are effective in photosynthesis. | photosynthetically active radiation (PAR) | photosynthetically active radiation (PAR) |
| phreatic | (- eruption); An explosive volcanic eruption caused when water and heated volcanic rocks interact to produce a violent expulsion of steam and pulverized rocks. Magma is not involved. | phréatique | freatische |
| phreatic (eruption) | An explosive volcanic eruption caused when water and heated volcanic rocks interact to produce a violent expulsion of steam and pulverized rocks. Magma is not involved. | phreatic (eruption) | phreatic (eruption) |
| physiology | (plant -). The organic processes and phenomena of an organism or any of its parts | Physiologie | fysiologie |
| physiology (plant) | The organic processes and phenomena of an organism or any of its parts | physiology (plant) | physiology (plant) |
| phytoplancton | All photosynthetic plankton, including e.g. unicellular algae and cyanobacteria. | phytoplancton | fytoplankton |
| pixel | (pic(ture) el(ement)); area corresponding to a single element of a digital image data set. | pixel | pixel |
| pixel value | Each of the pixels that represents an image stored inside a computer has a pixel value which describes how bright that pixel is, and/or what color it should be. The digital radiation value of a pixel, expressed as a digital number (DN) or digital count (DC), radiance value, reflectance or other radiation value. | valeur de pixel | pixelwaarde |
| polar | Polar orbit: orbit with inclinations near 90°. Tthe satellite crosses over (or nearly over) the north and south poles. | polaire | polair |
| Post-classification | Procedure carried out after a classification in order to improve its results. | post-classification | Post-classificatie |
| ppmv | Parts per million by volume. | ppmv | ppmv |
| Primary Data Users Station | The name for the equipment used to receive digital data from METEOSAT satellites. | Primary Data Users Station | Primary Data Users Station |
| pyroclastic flow | A hot, fast-moving and high-density mixture of fine and coarse particles and gas formed during explosive eruptions or from the collapse of a lava dome. | coulées pyroclastiques | pyroclastische stromen |
| Quaternary | Current geological period, characterised by the ascent and the flourishin of humanity, consists of the Pleistocene and Holocene epochs. | Quaternaire | Kwartair |
| RADAR | Radio Detection and Ranging. A method, a system, or a technique for using beam-, reflected-, and timed electromagnetic radiation to detect, locate, and track objects, to measure distance (altitude), and to acquire terrain imagery. The term 'radar' in remote sensing terminology refers to active microwave systems (from about 1 GHz - 100 GHz; the majority of current instruments operate below 10 GHz). | RADAR | RADAR |
| radar | Radio Detection and Ranging. A method, a system, or a technique for using beam-, reflected-, and timed electromagnetic radiation to detect, locate, and track objects, to measure distance (altitude), and to acquire terrain imagery. The term 'radar' in remote sensing terminology refers to active microwave systems (from about 1 GHz - 100 GHz; the majority of current instruments operate below 10 GHz). | radar | radar |
| radiative transfer | The fate of electromagnetic radiation as it is scattered, absorbed or reflected while passing through a medium. | radiative transfer | radiative transfer |
| radiometric correction | Correction of variation in data values that is caused by sensor malfunctions and atmospheric conditions. | radiometric correction | radiometric correction |
| radiometric corrections | Corrections of variations in data values that are caused by sensor malfunctions and atmospheric conditions. | corrections radiométriques | radiometrische correcties |
| radio-soundings | A electronics package attached to a balloon and carried aloft. It contains set of instruments that measure pressure, temperature, and humidity and a radio transmitter that transmits a data stream containing the information from the onboard sensor. | radio-soundings | radio-soundings |
| real time data | Refers generally to systems that respond immediately or synchronously to external event /Data that are acquired and transmitted immediately to the ground (as opposed to playback data). Delay is limited to the actual time (propagation delays) required to transmit the data | real time data | real time data |
| reflectance | Ratio of the intensity of reflected radiation to that of the incident radiation on a surface. | réflectance | reflectantie |
| reflectivity | Radar term referring to the ability of a radar target to return energy. | reflectivity | reflectivity |
| resolution | Spatial resolution or ground resolution is the minimum (spatial) surface of a feature or minimal distance between two features in order for a sensor to be able to discriminate them. Spectral resolution: The ability of a sensing system to resolve or differentiate electromagnetic radiations of different frequencies. Spectral and radiometric resolutions refer to the resolving power of a system in wavelength and energy, respectively. Temporal resolution: The frequency (in time) of remote sensing imaging possible with a particular sensor. | résolution | resolutie |
| rockfall | The sudden fall of one or more large pieces of a rock from a cliff. | rockfall | rockfall |
| RUE | Radiation Use Efficiency | RUE | RUE |
| RUE - Radiation Use Efficiency | RUE - Radiation Use Efficiency | RUE - Radiation Use Efficiency | |
| satellite image map | Satellite image resampled in a cartographic projection, with the eventual addition of graphical elements, comments and legends, e.g. resulting from the interpretation of the image. | satellite image map | satellite image map |
| scanner | A device that examines an area or region point by point in a continuous systematic manner, repeatedly sweeping across until the entire area or region is covered. | scanner (balayeur) | scanner |
| secant | A straight line that cuts a curve or surface at two or more points. Secants are used in the construction of some geometric map projections. | secant | secant |
| Secundary | Mesozoic: geological era following the Paleozoic era and divided into the Triassic, Jurassic and Cretaceous periods. | Secondaire | Secundair |
| seepage line | The uppermost level at which flowing water emerges along a seepage face Seepage face - A boundary between the saturated flow field and the atmosphere along which ground water discharges, either by evaporation or movement "downhill" along the land surface or in a well as a thin film in response to the force of gravity. | zone de suintement | zijpzone |
| semi-arid | (Semi-desert) areas with a semi-arid environment (climate) are characterised by a dry season lasting the major part of the year and minimal rainfall during the "wet" season. | semi-aride | semi-aried |
| shed | Shelter protecting game for bad weather, predators and human beings. | shed | shed |
| sidelap | The area common to two consecutive photos/images. The amount is expressed as a percentage of the total photo area. | recouvrement | longitudinale overlapping |
| sleeping sickness | Infection from the flagellate protozoan Trypanosoma brucei gambiense or the closely related subspecies T. brucei rhodesiense, transmitted by the tsetse fly. Sleeping sickness is characterized by fever and inflammation of the lymph nodes. | maladie du sommeil | slaapziekte |
| sonde | Device for testing physical conditions. | sonde | sonde |
| spatial data | Data, usually stored as coordinates, that describe the location, shape, and spatial relationships of geographic features. | données spatiales | gespatialiseerd (spatialisatie) |
| spectral band | A finite segment of wavelengths in the electromagnetic spectrum. | bande spectrale | spectrale band |
| spectral signature | The frequency distribution patterns of radiation reflected and/or emitted by an object. | signature spectrale | spectrale signatuur |
| spectrophotometer | A device for measuring the relative amounts of radiant energy or radiant flux as a function of wavelength. | spectrophotometer | spectrophotometer |
| spectroradiometer | Radiometer for carrying out measurements in a large number of small wavelength bands. | spectroradiomètre | spectroradiometer |
| spruce stand | Stand of trees of the genus (Picea, evergreen trees of the pine family with a conical head of dense foliage and soft light wood. | spruce stand | spruce stand |
| static slope failure | Slope failure (landslide, mudflow, rock slide,…) in static conditions, without external ground shaking, as opposed to dynamic slope failure where the rupture is triggered by an earthquake. The static slope failure can be triggered by heavy rains, storms, erosion or anthropic activities. | static slope failure | static slope failure |
| stereomicrometer | Device to determine the height (and relative difference in height) of an object on an aerial photograph based on the reading of radial image displacement. | stéréomicromètre | stereomicrometer |
| stereomodel | A stereoscopic model is a 3-dimensional optical image produced by combining the images from two overlapping aerial photographs, or other remotely sensed imagery (taken at slightly different angles) of the same area. | modèle stéréoscopique | stereomodel |
| stereoscopic | A science that deals with stereoscopic effects and methods of seeing overlapping twodimensional images in three dimensions. The area of overlap is called the stereoscopic overlap area. The pair of photographs is called a stereopair. | stéréoscopie | stereoscopisch |
| stratification | Structure produced by deposition of sediments in layers or beds. | stratification | gelaagdheid / stratificatie |
| stratigraphy | The study of the character, form, and sequence of layered rocks. | stratigraphie | stratigrafie |
| stratosphere | Region of the atmosphere between the troposphere and mesosphere, having a lower boundary of approximately 8 km at the poles to 15 km at the equator and an upper boundary of approximately 50 km. The stratosphere contains 90% of atmospheric ozone (O3). |
stratosphère | stratosfeer |
| stratovolcano | A steep-sided volcano composed of many layers of volcanic rocks, usually of high-viscosity lava and fragmented debris such as lahar and pyroclastic deposits. | strato-volcan | stratovulkaan |
| suitability of the site | Aptitude of an environment to meet the requirements of a species for development and survival. | bonité du site | geschiktheid van een site |
| sunsynchronous | An earth satellite orbit in which the orbital plane is near polar and the altitude is such that a satellite will always pass over a specific place on earth at the same local sun time and at fixed time intervals. | héliosynchrone | zonsynchroon |
| sustainable development | A concept that has emerged in recent years, based on the premise that development must meet the need of the present generation without compromising the ability of future generations to meet their own needs. | sustainable development | sustainable development |
| synoptic view | Observation of parameters over a distance spanning a continent. | vue synoptique | synoptische waarneming |
| tandem | In 1996, the ERS-1 and ERS-2 satellites started flying in tandem, meaning that ERS-2 is following ERS-1 in the same orbit with a 24 h time interval. | tandem | tandem |
| tangent | A mathematical term used in the construction of some geometric map projections describing a straight line or plane surface touching a curved line or curved surface at a single point but not intersecting it. | tangent | tangent |
| tectonic | Those major processes within the crust of the earth that lead to its structural deformation. | tectonique | tektoniek |
| ten-day synthesis products | Product compiled from daily synthesis over the previous ten days. The synthesis is delivered in a standard map projection. | produit de synthèse décadaire | tiendaagse synthese produkten |
| tephra | Solid material of all sizes explosively ejected from a volcano into the atmosphere. | tephra | tephra |
| texture | The visual or tactile surface characteristics and appearance of an object. | texture | textuur |
| thalweg | River profile. | thalweg | thalweg |
| thematic map | Map representing the disitribution, nature and/or quantity of certain (groups of) phenomena of topics on a topographic background. | carte thématique | thematische kaart |
| time series | Any series of observations of a physical variable that is sampled at (changing) time intervals. | série temporelle | tijdsreeks |
| tomography | Radiologic technique for determining physical characteristics of predetermined plane sections of a solid object (a rock massive or soil in the present case) based on surface measurements at various spots. | tomography | tomography |
| topographic factor | This factor forms part of the Universal Soil Loss Equation - USLE. For convenience, the slope length factor L and slope steepness factor S are frequently conjoined into a single topographic factor LS because the effect of steeper slopes and longer slopes is similar. Steeper slopes produce higher overland flow velocities. Longer slopes accumulate runoff from larger areas and also result in higher flow velocities. Thus, both result in increased erosion potential, but in a non - linear manner. | facteur topographique | topografische factor LS |
| topographic map | Map representing the topography according to preset criteria, providing the required accuracy and comprehensiveness for orientation and terrain study. | carte topographique | topografische kaart |
| topography | The configuration or shape of features on the Earth's land surface. Topography is depicted on maps by contour lines, hypsometric tints, and relief shading. | topographie | topografie |
| topology | A term that defines the spatial relationships between features(points, lines and surfaces) in a vector layer (touching lines, little surfaces enclosed in bigger surfaces,…). Topological relationships are useful in GIS, because spatial analyses often occur in absence of geographical coordinates. | topologie | topologie |
| toponymy | Taxonomic study of place-names, based on etymological, historical, and geographical information. | toponymie | toponomie |
| total station | A total station is a surveying instrument that combines an electronic theodolite and an electronic distance meter (EDM) to provide accurate measurements of both horizontal and vertical angles as well as distances. It is commonly used in construction, engineering, and land surveying projects to collect data for creating detailed maps, plans, and 3D models. |
Station totale | Totaalstation |
| transmittance | The ratio of energy transmitted by a body to that incident on it. | transmittance | transmissie |
| travertine | A mineral consisting of a massive usually layered calcium carbonate (as aragonite or calcite) formed by deposition from spring waters, especially from hot springs, and shallow waters with small rapids. The precipitation of carbonates is provoked by turbulence, and the loss of CO2. |
travertin | travertijn |
| triangulation | An accurate method of surveying based on the geometric principle that if the measurements of one side and two angles of a triangle are known then the other dimensions of the triangle can be calculated. Starting with a known base line, a network of known horizontal positions on the Earth's surface may be established by expanding a network of triangles, for once the other sides of the first triangle are calculated then one of them can be used as the base line for the next triangle. This process establishes horizontal control. | triangulation | triangulatie |
| troposphere | Bottom layer of the atmosphere. | troposphère | troposfeer |
| turbidity index | Measure of the turbidity of water. Turbidity: A cloudy condition in water due to suspended silt or organic matter. | index de turbidité | turbiditeitsindex |
| Universal Soil Loss Equation | (USLE). Equation providing techniques for prediction of average annual soil loss caused by sheet and rill erosion. USLE = A = R K LS P C with A = Annual soil loss; R = Rainfall factor; K = Soil erodibility factor; L = Field slope length factor; S = Field slope factor; (LS = Topographic factor); C = Cropping factor; P = Conservation practice factor (e.g. influence of terraces) C = cropping factor | Universal Soil Loss Equation | Universal Soil Loss Equation |
| Universal Soil Loss Equation - USLE | Equation providing techniques for prediction of average annual soil loss caused by sheet and rill erosion. USLE = A = R K LS P C with A = Annual soil loss; R = Rainfall factor; K = Soil erodibility factor; L = Field slope length factor; S = Field slope factor; (LS = Topographic factor); C = Cropping factor; P = Conservation practice factor (e.g. influence of terraces) C = cropping factor | Universal Soil Loss Equation - USLE | Universal Soil Loss Equation - USLE |
| URBIS | URBIS is a administrative, digital map reproducing the green areas of the Brussels regio. | URBIS | URBIS |
| validate (validation) | To support or corroborate on a sound or authoritative basis. | validate (validation) | validate (validation) |
| validation | To validate: to support or corroborate on a sound or authoritative basis. | validation | valideren |
| vector data | The representation of spatial data using points, lines, and polygons, digitally encoded according to their origins, breakpoints and terminators. | données vectorielles | vector(gegevens) |
| vector mask | Mask defined by its vector outline. | vector mask | vector mask |
| vegetation index | The reduction of multispectral scanning measurements to a single value for predicting and assessing vegetative characteristics such as plant leaf area, total biomass and general plant stress and vigor. In general, measurements from the red and infrared area of the electromagnetic spectrum are used for the calculation of vegetation indices because of the specific spectral signature of plants . | indice de végétation | vegetatie-index |
| viscosity | Resistance of a fluid (liquid or gas) to a change in shape, or movement of neighbouring portions relative to one another. | viscosité | viscositeit |
| visible light | Electromagnetic radiation with a wavelength between 400 and 750 nm, limited by the ultraviolet and the infrared channel. | lumière visible | zichtbaar licht |
| wadi | Seasonal river in arid areas. | oued | wadi |
| water cycle | Hydrological cycle. A complex group of processes by which water in its various forms is circulated through the earth/atmosphere system. It is powered by solar radiation which provides the energy to maintain the flow through such processes as evaporation, transpiration, precipitation and runoff. | cycle de l'eau | watercyclus |
| wetland | Area habitually saturated with water, which may be partly or wholly covered permanently, occasionally or periodically by fresh or salt water up to a depth of 6 m and that includes bogs, fens, water meadows, marshland and salt marshes, shallow ponds, river estuaries and intertidal mud flats, but excludes rivers, streams, lakes and oceans. | milieu humide | waterrijk gebied - wetland |
| whitecap | A wave crest breaking into white foam. | écume | schuimkop |