Sec 2-1 glossary of environmental terms Flashcards
Acid Rain
Precipitation with pH levels much below average as a result of the
formation of sulfuric acid in polluted air.
Active layer
The surface layer in a permafrost environment, which is
characterized by freezing and thawing on a seasonal basis
Aggradation
Filling in of a stream channel with sediment, usually associated with
low discharges and/or heave sediment loads.
Alluvial Fan
A fen-shaped deposit of sediment laid down by a stream at the foot
of a slope; very common features in dry regions, where Streams deposit their sediment load as they lose discharge downstream.
Aquifer
Any subsurface material that holds a relatively large quantity of groundwater and is able to transmit that water readily.
Backshore
The zone behind the shore - between the beach berm and the
backshore slope
Backshore slope
The bank or bluff landward of the shore that is comprised of <i>in situ
</i>material
Backswamp
A low, wet area in the floodplain, often located behind a levee.
bankfull discharge
The flow of a river when the water surface has reached bank level.
Baseflow
The portion of streamflow contributed by groundwater; it is a
steady flow that is slow to change even during rainless periods
Bay-mouth bar
A ribbon of sand
deposited across the mouth of a bay.
Berm
A low
mound that forms along sandy beaches; also used to describe elongated mounds constructed along water features and site borders.
Boreal Forest
Subarctic
conifer forests of North America and Eurasia; florlsticaily homogeneous forests dominated by fir, spruce, and tamarack; in Russia, it is called <i>taiga</i>.
Buildable Land Units
Parcels
of various size within a designated project area that are suitable for development as defined by a prescribed development program
Carrying capacity
The level of development density or use an environment is able to
support without suffering undesirable or irreversible degradation.
Choropleth map
A map comprised of areas of any size or shape representing
qualitative phenomena (eg,.soils) or quantitative phenomena (e.g. population); map often has a patchwork appearance
Climate
The representative or general conditions of the atmosphere at a
place on earth; H is more than the average conditions of the
atmosphere, for climate may also include extreme and infrequent
conditions.
Closed Forest
A forest structure with multiple levels of growth from the ground
up; a forest in which undergrowth closes out the area between the
canopy and the ground.
Coastal Dune
A sand dune that forms in coastal areas and is fed by sand from the
beach
Colluvium
An unsorted mix of soil and
mass-movement debris.
Conduction
A
mechanism of heat transfer involving no external motion or mass transport; instead, energy is transferred through the collision of vibrating molecules
Conveyance Zone
The central route of
drainage,
usually a channel and valley, in a drainage basin
Declination
of the sun
The location
(latitude) on earth where the sun on any day is directly overhead; declinations range from 23.27° S latitude to 23.27° N latitude.
Degradation
Scouring and
downcutting of a stream channel, usually associated with high discharges
Design storm
A rainstorm of a given intensity and frequency of recurrence used as the basis for sizing stormwater facilities such as stormsewers.
Detention
A strategy used in stormwater management in which runoffs detained on site to be released later at some prescribed rate.
Development
density
A measure of the intensity of development or land use; defined on the basis of area covered by impervious surface, population, density, or building floor area coverage for example
Drainage
basin
The are that contributes runoff to a stream, river, or lake.
Drainage
density
The number of miles (or km) of stream channels per square mile (or km1) of
land.
Drainage
divide
The border of a drainage basin or watershed where overland separates between adjacent areas.
Drainage network
A system of stream channels usually connected in a hierarchical fashion. See also Principles of stream orders.
Drainfield
The network of pipes or tiles through which wastewater is dispersed into the soil.
Ecosystem
A group of organisms linked together by a flow energy; also a community of organisms and their environment.
Ecotone
The transition zone between two groups, or zones, of vegetation.
Environmental assessment
A preliminary study or review of proposed action (project) and the influence it could have on the environment. Often conducted to determine the need for more detailed environmental impact analysis.
Environmental Impact Statement
A study required by US Federal law for projects (proposed)
involving federal funds to determine types and magnitudes of
impacts that would be expected in the natural and human
environment and the alternative courses of action, including no
action.
Environmental inventory
Compilation and classification of data and information on the
natural and human features in an area proposed for some sort of
planning project.
Ephemeral Stream
A stream without baseflow; one that flows only during or after
rainstorms or snowmelt events.
Erodibility
The relative susceptibility of a soil to erosion.
Erosion
The removal of rock debris by an agency such as moving water,
wind, or glacieis; generally, the sculpting or wearing down of the
land by erosional agents.
Eutrophication
The increase in biomass Of a waterbody leading to infilling of the
basin and the eventual disappearance of open water; sometimes
referred to as the aging process of a waterbody
Evapotranspiration
the loss of water from the soil through evaporation and transpiration.
Feasibility Study
A type of technical planning aimed at identifying the most appropriate use of a site.
Fetch
The distance of open water in one direction across a water body; it is one of the main controls on wave size.
Floodway fringe
the zone designated by the US Federal flood policy as the area in a river valley that would be lightly inundated by the 100-year flood.
Frequency
The term used to express how often a specified event is equaled or exceeded.
Frost wedging
A mechanical weathering process in which water freezes in a crack
and exerts force on the rock, which may result in the breaking of the rock; a very effective weathering process in alpine and polar environments.
Geomorphic System
A physical system comprised of an assemblage of landform linked
together by the flow of water, air, or ice.
Geomorphology
The field of earth science that studies the origin and distribution of
landforms, with special emphasis on the nature of erosional processes;
traditionally,
a field shared by geography and geology.
Grafting
The practice of attaching additional channels to a drainage network; in agricultural areas new channels appear as drainage ditches; in urban areas, as stormsewers.
Greenbelt
A tract of trees s and associated vegetation in urbanized areas; it may
be a park, nature preserve, or part of a transportation corridor.
Albedo
The percentage of Incident radiation reflected by a material. Usage
in earth science is usually limited to shortwave radiation and landscape materials.
Gross sediment transport
The total quantity of sediment transported along a shoreline in some time period, usually a year.
Ground Frost
Frost that penetrates the ground in response to freezing surface temperatures.
Ground sun Angle
The angle formed between a beam of solar radiation and the surface that it strikes in the landscape.
Groundwater
The mass of gravity water that occupies the subsoil and upper bedrock zone; the water occupying the zone saturation b elbow the soil water zone.
Gullying
Soil erosion characterized by the formation of narrow, steep-sided channels etched by rivulets or small streams of water. Gullying can be one of the most serious forms of soil erosion of cropland.
Habitat
The environment with which an organism interacts and from which it gains its resources; habitat is often variable in size, content, and location, changing with the phases in an organism’s life cycle.
Hardpan
A hardened soil layer characterized by the accumulation of colloids and ions.
Hazard assessment
Study and evaluation of the hazard to land use and people from environmental threats such as floods, tornadoes, and earthquakes.
Heat Island
The area or patch of relatively warm air which develops over urbanized areas.
Heat Transfer
The flow of hear within a substance or the exchange of heat between substances by means of conduction, convection, or radiation.
Hillslope processes
The geomorphic processes that erode and shape slopes; mainly mass movements such as soil creep and landslides and runoff processes such as rain-wash and gullying.
Hydrograph
A streamflow graph which shows the change in discharge over time, usually hours or days. See also Hydrograph method.
Hydrograph method
A means of forecasting streamflow by constructing a hydrograph that shows the representative response of a drainage basin to a rainstorm; the use of a ’normalized’ hydrograph for flow forecasting in which the size of the individual storm is filtered out. See also Hydrograph.
Hydrologic Cycle
The planet’s water system, described by the movement of water from the oceans to the atmosphere to the continents and back to the sea.
Hydrometer Method
A technique used to measure the clay content in a soil sample that involves dispersing the clay particles in water and drawing off samples at prescribed time intervals.
