The Water cycle - Local scale Flashcards
Where would you find a local scale water cycle?
A local drainage basin system
Is a local-scale water cycle an open or closed system?
Open
What are the inputs to a local-scale water cycle?
Precipitation - Rain, snow, hail
What are the three types of rainfall?
Convectional, Relief, Frontal
What is convectional rainfall?
Due to heating by the sun, warm air rises, condenses at higher altitudes and falls as rain
What is relief rainfall?
Warm air forced upward by a barrier such as mountains. Causes it to condense at higher altitudes and fall as rain
What is frontal rainfall?
Warm air rises over cool air (less dense). Condenses at higher altitudes and falls as rain
What are the outputs of a local-scale water cycle?
Evapotranspiration (evaporation & Transpiration).
Streamflow
What is evaporation?
Occurs when water is heated by the sun, causing it to become a gas and rise
What is transpiration?
Occurs in plants when they respire through their leaves, releasing water they absorb through their roots (then evaporation from sun)
What is streamflow?
All water that enters the atmosphere leaves by either entering the atmosphere..
Or through streams which drain the basin. They may flow as tributaries into rives or directly into lakes and oceans
What are the flows of a local-scale water cycle? (7)
Infiltration, percolation, throughflow, surface runoff (overland flow), groundwater flow, streamflow, stemflow
What is infiltration?
Water moving from ground into soil.
What is an infiltration capacity?
Refers to how infiltration occurs.
Grass crops and tree roots create passages for water to flow (increase infiltration).
If precipitation falls at greater rate than infiltration capacity, overland flow will occur
What is percolation?
Water moves from ground into porous rocks or rock fractures
What is a percolation rate?
Dependent on the rock fractures and the permeability. (Slow)
What is throughflow?
Water moves through soil into streams or rivers
What controls the rate of throughflow?
Dependent on the type of soil.
Clay soils with high field capacity and smaller pore spaces have slower rates.
Sandy soils drain quickly because they have lower field capacity and larger pore spaces and natural channels from worms. (moderate/fast)