Glossary of Terms

Glossary of Terms

a | b | c | d | e | f | g | h | i | j | k | l | m | n |
o | p | q | r | s | t | u | v | w | x | y | z

- A -

ABIOTIC -Non-living factors in the environment (air, water, sunlight, minerals, etc.). (abiotique)

ACCRETION -An increase by natural growth or addition, used in the Study in terms of increased beach area or wetland. (accrétion)

ACOUSTIC SOUNDINGS - Technique of determining bottom depth in a body of water by transmitting sound waves through the water and measuring the reflected signals. (échosondage)

ALGAE - Microscopic organisms found in or near water, classified as plants and capable of photosynthesis but having no roots, flowers or seeds. These constitute the primary producers in lakes. Freshwater and marine algae are found in many forms and are therefore a diverse group of photosynthetic plant organisms that vary widely in size, shape and color. Algae form ranges from the substance on rocks that it attaches to, to the froth on the water surface, to the seaweed on the shore. (algue)

AREA OF NATURAL AND SCIENTIFIC INTEREST (ANSI)- An area of land and water which, due to its natural landscapes or features, has been classified as having life science or earth science values related to protection, scientific study or education. (zone d'intérêt naturel et scientifique (ZINS))

ARCHIPELAGOS - Expansive water with many scattered islands or a group of islands. (archipel)

- B -

BARRIER BEACH - An offshore ridge of unconsolidated material (sand, pebbles, etc.) that runs parallel to a coastline, is formed in part by high tides and acts as a natural barrier. (cordon littoral)

BASIN; WATERSHED - The region or area of which the surface waters and groundwater ultimately drain into a particular course or body of water. ( bassin versant; bassin hydrographique)

BATHYMETRY - The measurement and charting of water depths in large bodies of water. (bathymétrie)

BENTHOS - The plants and animals that live at the bottom of a body of water (ocean, river, lake, pond, etc.) either attached or unattached to substrate (sediment, rock, plant, etc.). (benthos)

BIOTA - All plants and animals living in a given area. (biote)

BIRD GUILD - 1. A group of birds that have similar breeding habits. 2. A group of birds, not necessarily of the same species, that depend on the same environmental resources. (guilde d'oiseaux)

BOAT LAUNCHING RAMP - A sloping structure allowing small recreational water craft and trailers access to water. (rampe de mise à l'eau)

BOUNDARY WATERS TREATY OF 1909 - The agreement between the United States and Canada that established principles and mechanisms for the resolution of disputes between the two countries related to water. The International Joint Commission was created as a result of this treaty. (Traité des eaux limitrophes en 1909)

BREAKWATER - A barrier built offshore to protect a harbor or a beach from the force of waves. (brise-lames)

- C -

CHART DATUM - The water level used to calculate the water depths that are shown on "navigation charts" and are a reference point for harbour and channel dredging. (zéro des cartes)

CLIMATE - The prevalent weather conditions of a given region (temperature, precipitation, windspeed, atmospheric pressure, etc.) observed throughout the year and averaged over a number of years. (climat)

COAST - The land or zone adjoining a large body of water. (rivage)

COASTAL EROSION - The wearing away of a shoreline as a result of the action of water current, wind and waves. (érosion littorale)

COASTAL ZONE TECHNICAL WORK GROUP - A scientific and technical work group for the International Lake Ontario-St. Lawrence River Study that is investigating the impacts of water level fluctuations on shore property, with particular attention to erosion and flood processes. (Groupe de travail sur les zones littorales)

COLONIAL BIRDS -Birds that nest in groups. (oiseaux nichant en colonies)

COMMERCIAL NAVIGATION TECHNICAL WORK GROUP - A scientific and technical work group for the Study that is investigating the impacts of water levels on cargo shipping, including tug and barge operations. (Groupe de travail technique sur la navigation commerciale)

COMPUTER MODELLING - The use of computers to develop mathematical models of complex systems or processes. (modélisation informatique)

CONSERVATION - The planned management of a natural resource, with the goal of protecting and carefully preserving it from exploitation, destruction or neglect. (conservation)

- D -

DIGITAL ELEVATION MODEL (DEM) - A digital image of geographical features consisting of a grid, in which the colour of each cell reflects an average elevation above or below sea level. (modèle altimétrique numérique (MAN))

DIGITAL ORTHOIMAGERY - Computer-assisted cartography technique allowing representation of surface features with the positional accuracy of a map, through elimination of errors due to camera or sensor orientation and terrain relief. (orthoimagerie numérique)

DIGITAL ORTHOPHOTO - A computer-rendered image representing surface features, in which inaccuracies due to camera or sensor orientation and terrain relief have been removed. Such an image combines the positional accuracy of a map with the image quality of a photograph. (orthophotographie numérique)

DROWNED RIVER MOUTHS (also known as estuaries) - The place where lake and river waters mix. They provide valuable habitat for spawning fish, nesting and migrating birds, and many rare or specialized plants. These wetlands typically have deep organic soils that have accumulated due to deposition of watershed-based silt loads and protection from coastal processes (waves, currents, seiche, etc.). (embouchure submergée ou estuaire)

DUNE - a mound or ridge of sand formed by the action of wind or waves. (dune)

- E -

ECOSYSTEM - A biological community in interaction with its physical environment, and including the transfer and circulation of matter and energy. (écosystème)

EMERGENTS - Plants rooted in soil under water but which emerge partially above the surface. (plantes émergées)

ENDANGERED SPECIES - A species threatened with extinction. (espèce menacée d'extinction)

ENVIRONMENT TECHNICAL WORK GROUP -A group of scientific and technical experts that is investigating impacts of water level variations on fish, birds, plants and other wildlife in the Lake Ontario-St. Lawrence River system, with particular attention to ecological effects on wetlands. (Groupe de travail technique sur l'environnement)

EROSION - The wearing away of land surfaces through the action of rainfall, running water, wind, waves and water current. Erosion results naturally from weather or runoff, but human activity such as the clearing of land for farming, logging, construction or road-building can intensify the process. (érosion)

EXOTIC SPECIES - Non-native species found in a given area as a direct or indirect result of human activity. (espèce exotique)

- F -

FISH GUILD - 1. A group of fish that have share similar breeding habits. 2. A group of fish, not necessarily of the same species, that depend on the same environmental resources. (guilde de poissons)

FLOODPLAIN - The lowlands surrounding a watercourse (river or stream) or a standing body of water (lake), which are subject to flooding. (plaine d'innondation)

FLOW - The rate of movement of a volume of water over time. (débit)

FLUVIAL - Related to or living in a stream produced by a river. (fluvial)

FRAZIL ICE - Stream ice with the consistency of slush, formed when small ice crystals develop in super-cooled stream water as air temperatures drop below freezing. These ice crystals join and are pressed together by newer crystals as they form. (frasil)

FRESHET - The sudden overflow or rise in level of a stream as a result of heavy rains or snowmelt. (crue; crue nivale)

- G -

GABION - An open-ended, cylinder-shaped wire mesh container which is sunk into a bottom and filled with rocks to form a structure such as a dike used to prevent erosion. (gabion)

GENERAL CIRCULATION MODEL (GCM) - A three-dimensional computer representation of climate and its various components, used to predict climat scenarios. (modèle de circulation générale (MCG))

GEOGRAPHIC INFORMATION SYSTEM (GIS) - An information system used to store and manipulate (sort, select, retrieve, calculate, analyze, model, etc.) geographical data. (système d'information géographique)

GLOBAL POSITIONING SYSTEM (GPS) - A navigation system based on the transmission of signals from a network of satellites, which allows users anywhere on the planet to determine their exact location at all times. (système de positionnement global)

GROUNDWATER - Underground water occurring in soils and in pervious rocks. (eaux souterraines)

- H -

HABITAT - The particular environment or place where a plant or an animal naturally lives and grows. (habitat)

HYDRAULICS - The study of the mechanical properties of liquids, including energy transmission and effects of the flow of water. (hydraulique)

HYDRAULIC MODELING - The use of mathematical or physical techniques to simulate water systems and make projections relating to water levels, flows and velocities. (modélisation hydraulique)

HYDROELECTRIC POWER GENERATION TECHNICAL WORK GROUP - A group of technical experts for the Study that are evaluating how different regulation plans affect power generation. (Groupe de travail technique sur l'énergie hydroélectrique)

HYDROLOGIC ATTRIBUTES - Statistics on water levels and stream flows. (attributs hydrologiques)

HYDROLOGIC CYCLE - The natural circulation of water, from the evaporation of seawater into the atmosphere, the transfer of water to the air from plants (transpiration), precipitation in the form of rain or snow, and runoff and storage in rivers, lakes and oceans. (cycle hydrologique)

HYDROLOGIC MODELING - The use of physical or mathematical techniques to simulate the hydrologic cycle and its effects on a watershed. (modélisation hydrologique)

HYDROLOGY - The study of the properties of water, its distribution and circulation on and below the earth's surface and in the atmosphere. (hydrologie)

HYDROLOGY AND HYDRAULICS MODELING TECHNICAL WORK GROUP - A scientific and technical work group for the Study that is developing models to predict water levels and flows in the Lake Ontario-St. Lawrence River system, based on various regulation plans and climate scenarios. (Groupe de travail technique sur la modélisation hydrologique et hydraulique)

HYDROELECTRIC POWER - Electrical energy produced by the action of moving water. (hydroélectricité)

- I -

IMAGERY - Representation of objects as images through electronic and optical techniques. (imagerie)

IMPERIAL CONVERSION FOR FEET TO METERS - 1 foot = .305 meters. (conversion impériale des pieds en mètres)

IMPERIAL CONVERSION FOR INCHES TO CENTIMETERS - 1 inch - 2.54 centimeters. (conversion impériale des pouces en centimètres)

INFORMATION MANAGEMENT TECHNICAL WORK GROUP - A scientific and technical work group for the Study that is collecting and updating information on depths and elevations (bathymetric and topographic data) in critical areas of the Lake Ontario-St. Lawrence system and sharing findings with other work groups. (Groupe de travail technique sur la gestion de l'information)

INTERNATIONAL JOINT COMMISSION (IJC) - An international federal government agency formed in 1909 by the United States and Canada as an application of the Boundary Waters Treaty to oversee the resolution and prevention of disputes with regard to all bodies of water shared by the two countries, and to provide recommendations on such water management issues as water quality and water levels. (Commission mixte internationale (CMI))

INTERNATIONAL LAKE ONTARIO - ST. LAWRENCE RIVER STUDY - A study sponsored by the IJC to examine the effects of water level and flow variations on all users and interest groups and to determine if better regulation is possible at the existing installations controlling Lake Ontario outflows. (Groupe de travail international sur le lac Ontario et le fleuve Saint-Laurent)

- L -

LEACHATE - Contaminated liquid resulting from the percolation of water through pervious rocks and soils at a waste site or landfill. (lixiviat)

LIDAR - A remote-sensing system similar to radar, in which laser light pulses take the place of microwaves. (lidar)

LITTORAL - Shoreline. (littoral)

LITTORAL DRIFT - The movement of gravel, sand and other beach material along the coast, which is caused by waves and currents. (transport littoral)

LOW WATER DATUM - An approximation of mean low water, used for harbour-dredging purposes. (niveau de référence des basses eaux)

LOWER ST. LAWRENCE RIVER - The portion of the St. Lawrence River downstream of the Moses-Saunders Dam is called the Lower St. Lawrence in this Study. It includes Lac St. Francis, Lac St. Louis, Montreal Harbour, Lac St. Pierre and the portions of the River connecting these lakes as far downstream as Trois Rivieres. (bas Saint-Laurent)

- M -

MARINA - A private or publicly-owned facility allowing recreational watercraft access to water, and offering mooring and other related services. (marina)

MARSH - An area of low, wet land, characterized by shallow, stagnant water and plant life dominated by grasses and cattails. (marais)

METADATA - - Data (information) about the characteristics of data such as content, quality (condition, accuracy, etc.), date of capture, user access restrictions and ownership. (métadonnée)

META-DATABASE - A database used to store information about data (metadata). (base de données de métadonnées)

METRIC CONVERSION FOR CENTIMETERS TO INCHES - 1 centimeter = 0.4 inch. (conversion métrique des centimètres en pouces)

METRIC CONVERSION FOR METERS TO FEET - 1 meter = 3.28 feet. (conversion métrique des mètres en pieds)

MICRO-ORGANISM - An organism that is too small to be visible without the aid of a microscope. (micro-organisme)

- N -

NET BASIN SUPPLY (NBS) - The net amount of water entering one of the Great Lakes, comprised as the precipitation onto the lake minus evaporation from the lake, plus groundwater and runoff from its local basin. The net basin supply does not include inflow from another Great Lake. (apport net d'eau du bassin)

- O -

OUTFALL - The place or structure where a sewer, drain, conduit or stream discharges into the surface water. (exutoire)

OUTFLOW - The quantity of water flowing out of a lake through surface rivers or streams, measured in time units at a given point. (débit sortant)

- P -

PEAKING - The variation of hourly water flows above and below the daily average flow (for instance, midday flow higher than evening and night flows), primarily due to hydroelectric generating operations during which water is stocked during periods of off-peak demand in order to increase hydroelectric power generation at peak periods.(variation journalière)

PERFORMANCE INDICATOR - A measure of economic, social or environmental health. In the context of the Study, performance indicators relate to impacts of different water levels in Lake Ontario and the St. Lawrence River. (indicateur de performance)

PHOTOSYNTHESIS - The process through which the cells of green plants and certain micro-organisms convert energy from sunlight into stored, usable chemical energy. (photosynthèse)

PHYSICAL IMPACT SURVEY - A characterization study of the impact of water level fluctuation on infrastructure use or constraints. (étude des impacts physiqes)

PLAN 1958D - A plan used by the International St. Lawrence River Board of Control since April 1963 that specifies outflows from Lake Ontario in order to satisfy the existing set of criteria established by the IJC and related to interests on Lake Ontario and the St. Lawrence River. (Plan 1958D)

PLAN FORMULATION AND EVALUATION GROUP - A group established as part of the Study to develop alternative water level regulation plans, establish performance indicators for such plans, and to measure the effectiveness of such alternate criteria and operating plans. (Groupe de formulation et d'évaluation du plan)

PLAN FORMULATION METHOD - A method involving a multi-objective, multi-stakeholder evaluation procedure used to evaluate factors not previously considered in determining whether a revised operating plan performs better than an existing plan. (Méthode de formulation du plan)

PONDING - The variation of daily water flows above and below the weekly average flow (for instance, average weekday flow higher than average weekend flow), primarily due to hydroelectric generating operations. (variation hebdomadaire)

PRIORITY CONSERVATION SPECIES - A species protected by federal, state, or provincial laws. (espèce prioritaire pour la conservation)

PUBLIC INTEREST ADVISORY GROUP (PIAG) - The group of volunteers from the United States and Canada working to ensure effective communication between the public and the International Lake Ontario-St. Lawrence River Study Team. (Groupe consultatif sur l'intérêt public)

- Q -

QUARTER-MONTHLY MEAN WATER LEVEL - This is the average water level that would occur during a quarter-month period. A quarter-month is seven or eight days depending on the number of days in the month. (niveau d'eau moyen par quart de mois)

- R -

RAPIDS - A turbulent and swift-flowing section of a river. (rapides)

RECREATIONAL BOATING AND TOURISM TECHNICAL WORK GROUP - A group of technical experts that will investigate the impacts of water levels on individual boaters, marinas, and boating-related tourism for the Study. (Groupe de travail technique sur la navigation de plaisance et le tourisme)

RESERVOIR - - A place where water is collected and kept for use when wanted, as to supply a fountain, a canal, or a city by means of aqueducts, or to drive a mill wheel, or the like. (réservoir)

REVETMENT - A natural (grass, aquatic plants, etc.) or artificial (concrete, stone, asphalt, earth, sand bag, etc.) covering (facing) to protect an embankment (raised structure made of soil, rock or other material) or other structure (such as a cliff) from erosion. (revêtement)

RIPARIAN - Of, relating to or found along a shoreline. (riverain)

RIVERINE - Of or relating to a river or a riverbank. (fluvial)

- S -

SHARED VISION MODEL - A decision-making tool used to develop a collective representation (image or view) of the future a group aspires to create. (modèle de vision commune)

SHOALS (SCANNING HYDROGRAPHIC OPERATIONAL AIRBORNE LIDAR SYSTEM) - A LIDAR system that uses a green laser to profile underwater terrain and an infrared laser to detect water surfaces. The system is used to obtain bathymetric and topographic data. (SHOALS)

SOCIO-ECONOMIC SURVEY - A survey measuring the basic characteristics of a community, from which statistics can be compiled. (étude socio-économique)

SURFACE WATER - Water open to the atmosphere including lakes, ponds, rivers, springs, wetlands, artificial channels and other collectors directly influenced by surface water. (eaux superficielles)

- T -

TECHNICAL WORK GROUP (TWG) - A team of scientific and technical experts formed to study each of the following areas: the coastal zone, commercial navigation, common data needs, the environment, hydrology and hydraulics modeling, water uses, hydroelectric power generation, and recreational boating and tourism for the International Lake Ontario-St. Lawrence River Study. (Groupe de travail technique)

TOPOGRAPHY - The representation on maps or charts of the surface features of a region in such a manner as to illustrate their relative positions and elevations. (topographie)

TROPHIC - Of, or related to, nutrition. (trophique)

- U -

UPPER ST. LAWRENCE RIVER - The portion of the St. Lawrence River upstream of the Moses-Saunders Dam is called the Upper St. Lawrence in this Study. It includes the entire River from Kingston/Cape Vincent to the power dam and locks at Cornwall-Massena, including Lake St. Lawrence. (haut Saint-Laurent)

- W -

WATER LEVEL - The elevation of the surface of the water of a lake or at a particular site on the river. The elevation is measured with respect to average sea level. Several different types of water levels are used in the Study. In the case of Lake Ontario, the water level is assumed to be the calm water level without wind effects or waves included. In the erosion and flood analysis, these wind effects are added to the calm water level. Many of the analyses done in the Study use the quarter-monthly mean water level. This is the average water level that would occur during a quarter-month period (approximately a week). (niveau d'eau)

WATER USES TECHNICAL WORK GROUP - A technical and scientific team of the Study that is investigating impacts of water level variations on industrial, municipal, and domestic water intakes and treatment facilities. (Groupe de travail technique sur les utilisations de l'eau)

WATERFOWL - Birds that are ecologically dependant on wetlands for their food, shelter and reproduction. (sauvagine)

WATERSHED; BASIN - The region or area of which the surface waters and groundwater ultimately drain into a particular course or body of water. (bassin versant; bassin hydrographique)

WETLAND - An area characterized by wet soil and high biologically productivity, providing an important habitat for waterfowl, amphibians, reptiles and mammals. (zones humides)

WILLINGNESS TO PAY (WTP) - The maximum amount that a consumer will pay for a given item or service. (volonté de payer)

- Y -

YACHT CLUB - A member-owned facility allowing access to docks or mooring to recreational boaters, and often offering complementary services. (club nautique)

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Great Lakes Water Levels