Water cycle key terms 1 Flashcards
How are clouds formed?
- Air warms faster than surrounding via conduction
- Air rises via convection in thermals/air pockets
- Air cools at dry adiabatic lapse rate = 9.8°C per 1km
- Air expands, loses energy = cools (convection)
- Air becomes saturated at dew point (100% relative humidity) = water vapour condenses into droplets
- Air cools at saturated adiabatic cooling rate of 5.5°C per 1km.
- Droplets form clouds and the atmosphere is stable at the top of the cloud, when all air is the same temperature.
How does water move from vegetation?
Acts as an interception from precipitation. Transpiration, respiring leaves, stem flow to surface storage
State the stages that water takes to get to groundwater storage/ aquifers
Precipitation (interception, stem flow), surface storage, infiltration, soil storage, percolation (through rocks), groundwater storage
What is percolation?
movement of surface and soil water into underlying permeable rocks
What is an aquifer?
Water bearing band of pourrous or permeable rock, water infiltrates through soil then percolates into rocks.
Also known as groundwater storage.
How can geology affect the water cycle under ground?
more porous and permeable rocks = more water held via percolation forming aquifers.
What is channel storage and what does it lead to?
Storage of water In river channels. Goes to channel flow them ocean storage via estuarys
What is infiltration?
Movement of water from surface storage to soil storage
What is transpiration?
Evaporation of water from the pores (stoma) of leaves
Where can water go from soil storage?
Either percolate into rocks or move through soil via through flow into channel storage.
What type of system is the water system?
It’s closed
Why is the water cycle a closed system?
Only energy crosses boundaries, not matter because no new water is added, it just circulates
define a system
A group of objects and the relationship between them
What is sublimation?
Ice to water vapour directly
What is the difference between melting and sublimation?
Sublimation does not have a liquid phase but melting does
Where does precipitation go?
Onto interception (vegetation), surface storage, ocean storage and channel storage.
How do clouds moderate global temperature?
They absorb insolation (the suns radiation) as well as reflecting it, leading to reduced surface temperatures
How do oceans moderate global temperature?
Oceans absorb heat and release it via evaporation
How much of the earth surface is ocean storage?
71%
Socioeconomic uses of water:
- Irrigation for farming and food cycle maintenance
- energy generation (hydroelectric, wave, geothermal)
- recreational activities eg fishing, surfing, swimming
- manufacturing eg. paper, jeans, plastic
Biospheric importance of water:
- habitat maintenance
- photosynthesis input
- transport of nutrients in organisms
- metabolism
- forming and splitting molecules
- food cycle
define biosphere
The space at the Earth surface and within the atmosphere occupied by living organisms
Role of water vapour in the atmosphere
Absorbs long-wave radiation in the atmosphere to regulate global temperatures.
Define residence time
The length of time a molecule [eg H2O or CO2] that it spends in natural storage eg ocean, atmosphere
What are the 3 main water stores?
AOL - Atmosphere, oceans and land
Residence time of water molecule in the ocean
3000 years on average
Residence time of water molecule in the atmosphere
10 days on average
How much water is stored in the ocean in gigatonnes?
1,370,000 GT
How much water is stored in the atmosphere in gigatonnes?
13Gt
How much water is stored on land in gigatonnes?
39,000Gt
What’s the process of water from Land to atmosphere?
Evapotranspiration
What’s the process of water from atmosphere to the land or ocean?
Precipitation
What’s the process of water from ocean to the atmosphere ?
evaporation
What percentage of all global water is in oceans?
97% of all water is in oceans
What percentage of all global water is in aquifers or groundwater storage?
0.7% of all global water is in groundwater storage/aquifers
How does water moderate global temperatures?
- water vapour traps LW radiation
- ice reflects insolation
- clouds absorb and reflect insolation to reduce surface temperatures
- oceans absorb heat and get rid of it via evaporation
What is dew point?
When the air becomes saturated at 100% relative humidity.
Air condenses into water droplets.
= clouds, mist, fog.
What is the dry adiabatic cooling rate DALR?
Rate at which rising air cools which is 9.8°C per 1km.
What is the saturated adiabatic cooling rate SALR?
The rate at which saturated air rises which is 5.5°C per 1km.
What increases the risk of flash floods?
- Impermeable surfaces because of urbanisation
- Steep relief
- High rainfall
- Saturated soils
What are the different types of cooling?
- Convection (rising air pockets/thermals, expand, cool)
- Orographic and frontal uplift (air forced up over a mountain or because of denser cold air undercutting the warm)
- Radiation cooling (Thermal radiation releasing heat from ground, cooling surface temperatures)
What is the environmental lapse rate ELR?
- The average rate of air cooling which is 6.5°c per 1km
- Applies to surrounding air, not thermals/air pockets
- Also known as adiabatic cooling rate.
What are the 3 types of precipitation?
- Orographic (air forced to rise over mountain)
- Frontal (air forced upwards because of undercutting more dense cold air)
- Convection (rising air pockets cool and condense into clouds)
What’s the formula for calculating the water flow in a drainage basin?
Precipitation = (Run off + Evapotransp) +/- change in storage
P = (Q+E) +/- change in storage
