Water Cycles Flashcards
Dynamic equilibrium
where there is a balance between inputs and outputs
Closed system
there is a transfer of energy into and beyond the system but no matter
Open system
both energy and matter transfer freely into and out of the system
Oceanic water
5 oceanic bodies containing 72% of the earth surface area
Cryospheric water
made up of ice sheets, glaciers and permafrost
Terrestrial water
rivers and lakes, 52% of the freshwater on earth is stored in lakes and 1% in rivers
Atmospheric water
most common form is water, absorbs and reflects solar radiation
What can a small increase in water vapour do?
increase atmospheric temperatures (positive feedback)
Flood
a body of water that rises to overflow land that is normally submerged
Drainage basin
an area of land drained be a river and its tributaries
Lag time
the time taken from the peak rainfall to peak discharge
Base flow
the amount of water that would be in the river without the storm flow
Storm flow
overland flow and throughflow
Flashy hydrograph
short lag time, high peak discharge, sleep rising limb and sleep falling limb
Subdued hydoggraph
long lag time, low peak discharge and a gentle rising limb
Monsoon
a seasonal reversal in wind direction that brings a period of intense rainfall
Features of a river:
define 7 terms
- source: where water from surface runoff or from rock percolation, first forms a water channel to transfer water to a new store downstream
- tributary: smaller channel which joins the main channel and contributes to the total flow
- confluence: where rivers meet and join up
- flood plain: an area in the lower course which regularly floods during events of higher flow
- water shed: the border of the drainage basin
- estuary: governed by the tide, as sea and fresh water meet, the flow slows down and accretion occurs
- mouth: where the river meets the ocean
Features of a drainage basin:
define terms and sort into inputs (1), flows (7), stores (4) and outputs (3)
INPUTS:
-precipitation: water that falls to the earth in any form
FLOWS (transfers or fluxes):
-channel flow: precipitation directly entering the river channel
-stem flow: water reaches the ground by flowing down trunks or stems or by dropping off leaves
-overland flow: also called surface runoff, occurs during heavy rainfall when the ground is saturated or if surfaces are impermeable, very rare except in urban areas
-groundwater flow: water in this zone moves laterally (sideways) at a very slow rate. it transfers water to the river through the river bed and banks long after rainfall events
-percolation: a vertical movement of water from above the water table to below the water table, if the bedrock is impermeable, e.g. granite, no percolation occurs
-infiltration: the passage of water vertically into the soil. this does not occur if soil is saturated
-through flow: water flows laterally through the soil to the channel, mainly along ‘‘pipes’’ caused by animal activity or growth of plant roots
STORES:
-interception: raindrops fall on vegetation, preventing it from reaching the soil and river
-soil moisture: water stored in the soil above the water table
-surface water: water stored on the surface, e.g. lakes and rivers
-aquifers (groundwater): water stored below the water table in saturated soil or rock
OUTPUTS:
-evaporation: moisture lost into the atmosphere by the sun’s heat and wind
-evapotranspiration: biological process where water is loss as vapour through small pores in plant’s leaves
-river discharge: fresh water enters the ocean and so leaves the drainage basin
the drainage basin is a……………..system:
open system as matter (water) enters and leaves through the system barrier and energy is input
discharge is
River discharge is the volume of water flowing through a river channel. This is the total volume of water flowing through a channel at any given point and is measured in cubic metres per second (cumecs). The discharge from a drainage basin depends on precipitation, evapotranspiration and storage factors.
