EVS Ch. 1-3

Closed System
There is no exchange of matter with the outside of the system, but there can be energy inputs.
A group of related parts that move/work together
Geothermal energy origin
Radioactivity deep inside planet. Drives many geological processes
Tendency of a system to maintain stable or constant conditions
Residence time
Average amount of time a substance remains in a reservoir (time units)
Turnover time
Average amount of time to add or remove an amount of a substance to/from a reservoir that is equal to the actual amount of this substance in the reservoir.
The reaction of a system to an input
-Cline (Lake Chemistry)
Interface existing between various layers of water when in the absence of mixing
Oligotrophic Lake
Nutrient poor (young)
Eutrophic Lake
Nutrient rich (older). Eutrophication – often because of excessive primary productivity
Nuclear Energy
Generating electricity from steam made by harnessing the energy holding atomic nucleus together.
Uranium 235
Biological oxygen demand: a chemical procedure for determining how fast biological organisms use up oxygen in a body of water
The physical breakdown and/or chemical alteration of rocks and minerals at Earth’s surface
Physical (Mechanical) Weathering
Physical disintegration of rock. No chemical change
Chemical Weathering
Interaction with atmosphere, hydrosphere, etc causes change in chemical makeup of rock
Biological Weathering
Living things break down parent rock by physical or chemical means
Soil Profile: Top Soil
Inorganic minerals, organic matter & partly decayed organic matter (humus)
Soil Profile: Leached Zone
Mineral grains remaining from dissolution (ex, quartz). Low OM
Soil Profile: Accumulation Zone
Minerals (such as oxides of Fe and Al) and OM leached from a horizon accumulate here
Soil Profile: Course Rock
Large rock particles only slightly weathered from underlying bedrock
Watershed/Drainage Basin
Area where surface water converges to a single point at a lower elevation, where waters join another water body. Can be used in water management
Water Quality: pH Parameter
Chemical. Natural waters are usually acidic due to equilibrium with atmospheric CO2
Capacity of a solution to neutralize acids
Capacity of a solution to conduct electricity. Highly correlated to TDS
Hydrological Cycle: Four Main Reservoirs
Oceans, Surface Waters, Groundwater, Atmospheric water
Evaporation of water from plants
All sources of evaporation in a given location
Infiltration and groundwater flow
Movement of water underground
The slow movement of water through the pores in soil or permeable rock
Water density differential barrier, located in metalimnion (middle layer of stratified lake)
Lake Stratification
Separation of the lake into 3 layers: EPILIMNION, METALIMNION, HYDROLIMNION
Surface flow of rainwater
Tributary Stream
Discharges into a larger stream
Seasonal/Intermittent Stream
(Stream or PART of a stream) Flows for only part of the year
Perennial Stream
Flows all year long
Flood Plain
Area of low-lying ground next to a river, subject to flooding
Sustainable Development
Development using land or energy sources in a way that meets the needs of people today without reducing the ability of future generations to meet their own needs
One substance taking up another at its’ surface
Requiring air or oxygen: used when referring to decomposition processes that occur in the presence of oxygen
Algal Bloom

the rapid and excessive growth of algae; caused by high nutrient levels combined with other favourable conditions. can deoxygenate water leading to the loss of wildlife


We Will Write a Custom Essay Specifically
For You For Only $13.90/page!

order now

In freshwater ecosystems, algae growth is limited by phosphorus availability. 

Cultural Eutrophication: 

Form of water pollution 

Nutrient pollution 

Human activity speeds up natural eutrophication. 


Clearing land/building towns & cities -> increased land run off into waters -> nutrient pollution (ex, phosporus & nitrogen) -> algal blooms 



Accumulation of salt in soil that could eventually make the soil unable to support plant growth.
Negative Feedback
Self-regulating/stabilizing. Usually keeps a system in a relatively constant condition
Positive Feedback

aka “Vicious Circle”: Destabilizing.


Example: Forest fire. Fire grows, nearby wood dries out and begins to burn, drying out larger quantities of wood, feeding the fire. 

Example 2: Exponential Growth