The Water Cycle Flashcards

Flashcards about the water cycle

Open systems

Systems have external inputs and outputs of energy and matter exchange at its boundaries

Closed systems

Systems only have energy as their input and output; matter is contained within the system boundary

Isolated systems

Systems do not share matter or energy with their surroundings

Cascading systems

Where energy and material are transferred from one subsystem to another

Input

Matter or energy moving into a system from the outside

Output

Matter or energy moving from the system to outside the system orto another system

Stores/components

Individual parts/elements ofthe system

Flows/transfers

The movement of parts within the system

Processes

The stores/components and inputs are worked upon and changed

Equilibrium

A state of balance within systems where inputs and outputs are equal and processes operate to maintain the balance

Feedback loops

Active mechanisms in systems that maintain or restore equilibrium

Positive feedback

Amplifies the change Itis where one change leads to another

Negative feedback

'Checks' or dampens change Itis self-regulating to promote stability and maintain equilibrium

Dynamic equilibrium

A system in a steady, total state of balance

Water

A colourless, tasteless, transparent, odourless liquid that forms the seas, rivers and precipitation

Stores orreservoirs

A body of waterthat acts as a holding point

Hydrological cycle

The continuous movement of water on, above and below Earth's surface

Evaporation

The sun evaporates surface water into vapour

Condensation

Water vapour condenses and precipitates

Flows

Water runs o the surface into streams and reservoirs or beneath the surface as ground ow

Interception

How precipitation is prevented from reaching the ground, usually by being caught on leaves or branches

Aquifer

A rock which stores water

Unconfined aquifer

Where porous rock is open to surface water and is directly recharged by precipitation

Confined aquifer

Where there are thick layers/beds ofrock overthe aquifer, known as the con ning beds

Precipitation

Transfer of waterfrom the atmosphere to the Earth's surface in the form ofrain, hail, snow and dew

Interception

Precipitation thatis caught and stored (temporarily) on its way to the surface by leaves, plants, grasses and tree

Overland/Surface Flow

This is when water ows overthe land's surface

Infiltration

Where the water enters small openings and pores in the ground from the surface

Throughflow

Through ow is the lateral (sideways) movement of waterthrough the upper soil

Percolation

Where water ows down through the soil layers and underlying rock

Groundwater Flow

Also called base ow and is waterthat has in ltrated and percolated into the bedrock and below the watertable

Evapotranspiration

Combination of evaporation and planttranspiration

Condensation

Transfer of waterfrom a gaseous (vapour) state to a liquid state as in cloud formation

Sublimation

This is when water changes from a solid (ice)to a gas (vapour) without passing through a liquid state or vice versa

Trunk and Stem Flow

This is the ow of water down the stems of plants ortrunks oftrees

Zone of saturation

Where there is permanent saturation

Throughfall

Precipitation that makes itto the ground withoutinterception by the plant canopy

Drip flow

Waterthat ows o leaves and drips to the ground

Trunk and stem

The ow of water down the stems of plants ortrunks oftrees

Overland surface ow

When water ows overthe land surface

Channel ow

Where water ows in small channels or rills (<30cm width or depth) in a de ned stream pattern

Sheet ow

A layer of water on the surface, either due to excess surface ow from increased precipitation or water cannotin ltrate quickly enough

Hortonian overland ow

Describes the tendency of waterto ow horizontally across land surfaces when rainfall has exceeded in ltration capacity and depression storage capacity

Drainage basin

An area of land drained by a river and its tributaries

River discharge

The volume of water passing a pointin the river channel at a given unit oftime

Water balance

The balance between inputs and outputs

Discharge

The volume of water moving past a pointin a river per given time

Annual hydrographs

Show the pattern of seasonal variation thattakes place through a drainage basin to river discharge over a year

Storm hydrographs

Show changes in a river’s discharge during and after a storm

Totalruno

Expressed as a percentage of precipitation Itis a measure ofthe amount of total precipitation, within a drainage basin, that transfers into rivers and streams

Climate change

Increasing globaltemperatures reduce mountain glacial ice and the availability offreshwaterfor communities dependent on this water

Water abstraction

The growth ofthe global population has increased the demand for water supplies. Excessive removal of aquifer water means thatrecharge cannot keep up and stores are depleted

Land use change

Changes to an urbanised landscape increase impermeable surfaces, leading to increased runo and reduced in ltration

Deforestation

Vegetation removalfor agriculture, urbanisation or rewood forfuel supply, impacts an important water storage and transfer capability

Farming practices

Wells used as the main source ofirrigation for plants can lower groundwater and river channel levels

Transpiration

The changing of waterto water vapour by plants/evaporation of water by plants/trees/vegetation

Water table

The level of ground water

Water inputs

Can come from precipitation or groundwater storage

Percaline flow

Water that flows laterally, parallel to the ground surface

Surface run-off

Water drains into a river channel

Edge of a drainage basin

Watershed

The origin of a river

Source

A river that flows into a larger river

Tributary

The end of a river

Mouth

Method of measuring discharge

Hydrograph

The percentage of the total volume of a rock or sediment that consists of open spaces

Porosity

The ability of a rock or sediment to transmit water

Permeability

The maximum rate at which a soil can absorb water

Infiltration capacity

The time interval between the peak of rainfall and the peak of river discharge

Lag time

The part of a storm hydrograph that shows the increase in river discharge

Rising limb

The part of a storm hydrograph that shows the decrease in river discharge

Falling limb

The normal discharge of a river

Base flow

The maximum discharge of a river

Peak discharge

The growth of cities

Urbanization

The clearing of forests

Deforestation

The artificial watering of land

Irrigation

The process by which salt accumulates in the soil

Salinization

Water that flows over the land surface

Run-off

The process by which precipitation is intercepted by vegetation

Interception

The process by which plants release water vapor into the atmosphere

Transpiration

The process by which water changes from a liquid to a gas

Evaporation

The process by which water vapor changes from a gas to a liquid

Condensation

Any form of water that falls from the atmosphere to the Earth's surface

Precipitation

Water that is stored underground in aquifers

Groundwater

Water that is found on the Earth's surface in rivers, lakes, and oceans

Surface water

Water that is stored in the soil

Soil moisture

The upper limit of the zone of saturation

Water table

The area below the water table where all of the pore spaces are filled with water

Zone of saturation

The amount of water that is needed to meet the demands of evapotranspiration

Water deficit

The amount of water that is available after the demands of evapotranspiration have been met

Water surplus

Water accumulates on earth's surface (lakes, wetlands, puddles, etc

Surface storage

Global hydrological cycle

The global hydrological cycle shows annual ows of water between global stores