FINAL REPORT - International Joint Commission

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.
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.).
EUTROPHIC – Waters high in nutrient content and productivity arising either naturally or from
agricultural, municipal, or industrial sources; often accompanied by undesirable changes in aquatic
species composition.
EVALUATION – The application of data, analytical procedures and assessment related to criteria to
establish a judgment on the relative merit of a measure, policy or institution. Evaluation is a process
which can be conducted both within formal studies and by separate interests, although different data,
procedures and criteria may be employed in the evaluation by different interests.
EVALUATION FRAMEWORK – A systematic accounting of the criteria considered and methodologies
applied in determining the impact of measures on lake levels, stakeholders, and stakeholder interests.
EVAPOTRANSPIRATION – Evaporation from water bodies and soil and transpiration from plant surface.
EXOTIC SPECIES – Non-native species found in a given area as a direct or indirect result of human activity.
FEEDBACK LOOP – Feedback loops are circular cause and effect relationships dominating some interaction
of particular sets of system’s key variables. Feedback loops belong generally to one of two types.
“negative feedback loops” which act to maintain the value of a particular variable around a given level,
and “positive feedback loops” which act to cause the value of a particular variable to increase or
decrease in a self-amplifying manner; and, usually at a geometric rate.
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.
FLOOD AND EROSION PROTECTION SYSTEM (FEPS) – A series of numerical models including COSMOS
that compile and evaluate shoreline data to compute flood and erosion damages.
FLOODING – The inundation of low-lying areas by water.
FLOODPLAIN – The lowlands surrounding a watercourse (river or stream) or a standing body of water
(lake), which are subject to flooding.
FLOW – The rate of movement of a volume of water over time.
FLUCTUATION – A period of rise and succeeding period of decline of water level. Fluctuations occur
seasonally with higher levels in late spring to mid-summer and lower levels in winter. Fluctuations
occur over the years due to precipitation and climatic variability. As well, fluctuations can occur
on a short-term basis due to the effects of periodic events such as storms, surges, ice jams, etc.
FLUVIAL – Related to or living in a stream produced by a river.
FRAZIL ICE – Stream ice with the consistency of slush, formed when small ice crystals develop in supercooled
stream water as air temperatures drop below freezing. These ice crystals join and are pressed
together by newer crystals as they form.
FRESHET – The sudden overflow or rise in level of a stream as a result of heavy rains or snowmelt.
GLOSSARY OF TERMS
Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows
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