This list is meant to provide
watershed residents with a better understanding of some of the terms that are
often used when watershed planning and stream enhancement takes place. It is a collection
of definitions from A Technical Manual
for Stream Improvement on Prince Edward Island (Morell River Management
Co-op Inc. March 1994.) and A Guide to
Watershed Planning on Prince Edward Island (Prince Edward Island Department
of Environment, Energy & Forestry, 2007.).
Anoxia/hypoxia:
Depleted oxygen levels, often
caused by the decay of aquatic plants, which can kill fish, invertebrates and
other aquatic organisms.
Biodiversity:
All plant and animal life and the
ecological infrastructure that supports it
Brackish Water
Water with a salinity (salt
content) mid-way between fresh and salt water. Estuaries where freshwater meets
saltwater are considered to be brackish.
Buffer Zone:
The ecologically sensitive area
bordering both sides of a stream, river, or pond
Clearcut:
An area of forest, one hectare or
greater in size, where all or most of the trees have been removed
Deadfall:
Fallen trees, usually conifers or
evergreens, often crossing the stream
Drainage Basin:
The area in which all the run-off
collects to flow through one river. Also known as a catchment or a watershed.
Estuary:
A semi-enclosed body of water,
connected to the ocean, where salt water and fresh water from the land mix.
Eutrophic/eutrophication:
The gradual increase and
enrichment of an ecosystem by nutrients such as nitrogen and phosphorus
Forest Cover Type:
The tree species forming a
majority of the composition across a given area
Geographic Information System (GIS):
A computer information system
that can input, store, manipulate, analyze and display geographically
referenced (spatial) data to support land use decision making processes.
Global Positioning System (GPS):
A system of computers, satellites
and receivers that calculate, coordinate and determine the factors such as
position, altitude, boundaries and other mapping features.
Gradient:
The slope of a river
Head of Tide:
The upper limit of tidal
influence on a river
Hydrological Water Cycle:
The cycle by which water passes
from the atmosphere onto the earth’s surface, into the ground, and back again
Impoundment:
Water contained by a man-made or
natural dam (eg. A beaver dam)
Land Conversion:
An area of forest where all of
the trees have been removed and where the site will be permanently converted to
another use
Meandering:
The process by which a stream
winds or snakes its way across a floodplain
Non-Point Source Pollution:
Pollution which arises from many
sources (car exhaust, lawn chemicals,) rather just a centralized source (city
sewage)
Nutrient Enrichment:
A process which increases
nutrient inputs into a water table or aquatic system causing excessive production
of organic matter (plant growth) in the aquatic system.
Stewardship:
The act of caring for the land
through responsible land ownership and management
Over Enrichment:
A situation which occurs when
high concentrations of nutrients (eg. Nitrates, phosphorous) reach watercourses
and often cause a dense growth of algae. In some instances, dissolved oxygen
can become reduced.
Riparian Zone:
Pertains to the area of land
immediately adjacent to a water body
Watershed:
The area of land where runoff and
groundwater flows into a specified body of water such as a river, lake, sea, or
bay
Watershed Management:
Managing forests, fields and
human activities to ensure the ongoing health and supply of the water resource
and the people who depend upon it
Wetland:
A lowland area, such as a marsh
or swamp that is saturated with moisture, especially when used as a natural
habitat for wildlife
