the water cycle Flashcards
what are the earths major water stores
cryosphere: all parts of earth where its cold enough for water to freeze
lithosphere: the crust and upper parts of the mantle
hydrosphere: all water on earth in all states of matter
atmosphere: layer of gas between the earths surface and space held by gravity
biosphere: includes all living things
what is a cascading system
when the outputs of one subsystem are the inputs of another causing energy and matter to move from one subsystem to the next
e.g. the earth is a cascading closed system
how is saline and fresh water in the hydrosphere distributed?
- 1.4 sextillions litres of water
- 97% the water is saline ocean water
- less than 3% is freshwater
how is the total 3% of fresh water distributed?
- 69% is frozen in the cryosphere
- 30% is groundwater- stored in lithosphere
- 0.3% is liquid freshwater
- 0.04% is stored as water vapor in the atmosphere
what is evaporation
the change in state due to a gain in energy (typically solar radiation) where liquid water becomes gas/water vapor
how does evaporation effect the magnitude of major water stores on a spacial and temporal scale
- evaporation effect will vary according to season and location which effects solar radiation and water supply.
- high levels of evaporation will reduce the magnitude of hydrosphere store and increase the magnitude of the atmosphere store.
what is condensation
the change in state due to a loss in energy to surroundings where water vapour becomes liquid
how does condensation effect the magnitude of major water stores on a spacial and temporal scale
- condensation will vary according to season and location which effects the supply of water vapor and temperature.
- high levels of condensation will increase the magnitude of the hydrosphere store and decrease the atmosphere store.
how does clouds formation affect the magnitude of water stores
- warm air condenses to form water vapor that gathers to form clouds which increases the magnitude of the atmospheric store.
- when the droplets are big enough they fall as precipitation which increases the magnitude of the hydrosphere store and decreases the atmospheric store
how do air masses lead to precipitation
- less dense warm air meets cool air and is forced above it. as the warm air rises it cools
- this is frontal precipitation
how does typography lead to precipitation
- warm air meets mountain forcing it to rise and cool
- this is orographic precipitation
how does convection lead to precipitation
- moisture from the ground evaporates and rises in a column of warm air due to the suns heat. as it gets higher it cools
- this is convective precipitation
name two cryospheric processes and their effects on the magnitude of water stores
accumulation: the input of ice or snow
- increases the magnitude of the cryosphere store
ablation the output of water
-decreases the magnitude of the cryosphere store
what type of system are drainage basins
closed, local hydrological systems where rain falls on land and flows into the river.
boundary=watershed
name the inputs in drainage basin system
precipitation in the form of rain, snow, hail, dew and frost
name 5 forms of storage in a drainage system
- interception: precipitation lands on vegetation or other structures
- surface storage: water in puddles, ponds and lakes
- soil storage: moisture in soil
- groundwater storage: water stored in the ground,rocks or soil
- channel storage: water held in a river or stream channel
name 4 flows in a drainage basin system
- stem flow: water running down a plant stem
- infiltration: water soaking into soil
- overland flow: water flowing over land
- channel flow: water flowing in the river
name 2 outputs in a drainage basin system
- evapo-transpiration: process of evaporation and transpiration together
- runoff: the water that enters a river channel flows out of the drainage basin
what is water balance
- shows a balance between the inputs and outputs of a system
- in wet seasons there is more precipitation than evapotranspiration leading to a surplus of water.
- in dry season there is more evapotranspiration than precipitation leading to a water deficit causing groundwater stores to be depleted.
- this deficit is recharged in the wet season
name the 4 parts of a hydrograph
- lag time: the delay between peak rainfall and peak discharge
- rising limb: the period of time leading up to peak discharge
- peak discharge: the point on the graph where river discharge is highest
- falling limb: the period of time following peak discharge
5 things that make a flashy hydrograph
- a steep hydrograph with roughly symmetrical rising and falling limbs typically occurs at basins with:
- rapid runoff
- low storage capacity
- short lag time
- circular basins = high peak discharge as all points are similar so water reaches point at similar time
4 factors affecting run-off and hydrograph shapes
- size of drainage basin
e. g. large basin catches more water= higher peak discharge - shape of the drainage basin:
e. g. circular basins = high peak discharge - steepness of the ground
e. g.water flows more quickly downhill: short lag time=less infiltration=more run off
-rock and soil type: less infiltration=more run off=higher peak discharge
natural factors causing variation in the water cycle
storms and precipitation:
-intense storms= more precipitation=increased magnitude of hydrosphere stores
seasonal changes and vegetation:
-size of inputs, flows and storms varies with season
name 4 ways human farming practices cause variation in the water cycle
- ploughing causes increased infiltration and decreases run-off
- crops cause increased infiltration, interception and evapotranspiration which can increase rainfall
- livestock trampling ground decreases infiltration and increases run-off
- irrigation can increase run-off if no more water can infiltrate
human factors causing variations in the water cycle
land use change
- deforestation decreases interception and infiltration
- construction decreases infiltration as there are less permeable surfaces
human factors causing variations in the water cycle
water abstraction
-water stores can be depleted if water is extracted for irritation or to meet the demands of the population
