Water Cycle Knowledge Flashcards
(49 cards)
Stages of the global hydrological cycle
1) solar energy from sun evaporates water
2) water-> water vapour as it rises and cools in the atmosphere, forming clouds through condensation
3) water droplets collect and when heavy, clouds bursts
4) GPE-> KE as water falls and moves trough the sysem by plant nterception and SRO
5)some water is infiltrated through soil, some percolate trough porous,permeable rock
What is the global water budget
Distribution and movement of water within the earths hydrosphere, water is constantly cycled through different stores and reservoirs via processes like evaporation but can change throughout the yrs
E.g. northern hemisphere in temperate latitudes, precipitation may be similar all yr round but the evapotranspiration rates will be much higher in summer leading to soil water deficits in the summer months. Then when weather starts to cool, evapotranspiration levels fall then the soil moisture is recharged until it becomes full which caused a surplus at the start of the yr then cycle repeats
Is water considered to be renewable
It is generally considered a renewable resource because it is continuously replenished through the hydrological cycle
However, its renew ability depends on the specific context and time scale
Examples of renewable and non renewable water sources
Renewable- freshwater sources e.g. rivers
Non relabel- deep aquifers e.g. ogallala aquifer takes thousands of years to recharge
Therefore, a water’s classification as renewable or non renewable depends on its source, rate of replenishment and human consumption patterns.
What is residence time and how can it limit human water use
Average amount of time water spends in a specific reservoir within he hydrological cycle and how quickly it can be replenished ad sustainably used
What is short residence time and how can it affect human usage
Waters in rivers have SRT, meaning that it is readily available but highly dependent on seasonal and climatic variations e.g. droughts can quickly deplete water availability
What is LRT and how can it affect human water usage
Water stored in deep aquifers and takes thousands of years to recharge ( centuries to millennia)
E.g. water locked in glaciers and ice sheets (cryosphere), Antarctica,has LRT. Melting glaciers due to CC provide temporary water for down stream rivers but cannot sustain long term water needs cuz ice takes thousands of yrs to regenerate -> poses challenge for regions, South Asia, where millions rely on glacier fed river, Ganges
Why is understanding residence times important
Understanding these time frames is essential for managing water resources effectively, particularly in a world facing increasing water stress and CC
How does orographic rainfall (input), affect drainage basin
Moist air is forced to rise over a mountain/elevated terrain, air rises, it cools due to temps decreasing at higher altitudes ( adiabatic cooling), condensed to form clouds, precipitation occurs on the windward side of mountain, air descends on leewards side, experiences drier conditions to create rain shadow(drier regions) , Andes Mountain in SAmerica created a rain shadow called the are atacama desert
Another example, mawsynram India highest annual rain as moist air from Bay of Bengal forces to rise over khasi hill (467inches of rain)
How does frontal rain (input) affect drainage basin
2 air masses of different temperatures and densities meet at a front. Warm air rises over cold air mass because it is less dense, rises, cools, condenses, clouds…. E.g. mid / temperate latitude regions, UK where warm air created from Atlantic meets cooler polar air creating cyclonic system w heavy rain
How does convectional rain (input) affect drainage basin’
Earth’s surface heats up due to intense solar radiation, causing warm air to rise,cools,condense…… forming towering cumulonimbus clouds= heavy rain e.g. tropical regions Amazon where high temps and humidity Create daily thunderstorms
However for these inputs….
These types of rainfall differ based on their cause and location
Most rainfall areas
Tropical zones
Intertropical convergence zones belt of low pressure near equator where trade winds from north and south hempisphere converge e.g. monsoons in South Asia
During the summer, the ITCZ shifts northwards over South Asia intensify monsoon as it brings over warm waters from Indian Ocean
Countries like India and Bangladesh experice severe monsoon due to high rainfall, location in relation to the ITCZ And low lying topography
Causing Ganges river to overflow, detrimental as many rely on the Ganges river for water
Least rainfall areas
High pressure systems (anticyclone); descending dry air that inhibits cloud formation and precipitation e.g. Sahara and atacama desert chile at around 30 latitude, 1mm of rain ancually due to its location in a rainsheadow and presence o cold ocean currents
Continentality; regions distance from large bodies of water, have low precipitation as they lack moisture e.g. Central Asia , semi arid due to its distance from moisture sources e.g. Indian Ocean
How do flows and transfers affect drainage basin
Determine how fast and volume of water moving thru a system
How does permeability affect drainage basin
Porous rock (limestone), allows water to infiltrate rapidly, leading to greater storage in groundwater and slower transfers via through flow or groundwater flow
How does vegetation affect drainage basin
Dense vegetation intercept rain , decrease SRO, facilitates evapotranspiration, retiurning water to the atmosphere and decreasing volume moving through basin
How does temperature affect evapotranspiration (EVT)
Increase temp=higher EVT as it provides more energy for the evaporation of water and transpiration of plants e.g. in tropical climates
How does strong winds affect EVT
They enhance movement of water vapour from surface
How does vegetation affect EVT
Forested areas have higher EVT as large leaf surfaces promote faster rate of transpiration cuz more water is released into the atmosphere through stomata
How do humans affect drainage basin through deforestation
Deforestation=less vegetation, meaning there is a reduced water uptake by plants and less moisture returning to the atmosphere
Abundance of tree roots weaken soil structure, increasing SRO and accelerating overland flow ( use thus term whenever u mention SRO) e.g. amazon logging increases overland flow, decreases regional rainfall thru lower transpiration rates
How does urbanisation affect drainage basin
Replacement of natural surfaces w/ impermeable material, concrete, no infiltration, rapid SRO as overland flow into drainage basin e,g, expansion of cities Houston USA increases flooding due to hurricane Harvey 2017
Explain a physical cause of drought: ITCZ, El Niño
The subtropical high pressure zone interrupts the intertropical convergence zone which is a belt of low pressure.
The SHPZ prevents cloud formation and lead to persistent dry conditions
The ITCZ moves north and south seasonally bringing in rainfall to tropical regions.
However, the SHPZ acts as a barrier,preventing the ITCZ from moving further into drier regions e.g. Atacama desert( driest in world), is kept dry due to the persistent high pressure zone
El Niño= changes in temperature patterns within the Pacific Ocean, where trade winds blow west to east, causing warm water to move eastwards, causing droughts within the western pacific e.g. Australia.
La Niña= trade winds blow strong from east to west, causing droughts within over South America on the eastern seaboard of the pacific.
How is the subtropical high pressure formed?
Plays a major role in disrupting ITCZ
Created when the Hadley cell causes warm air to rise at he ITCZ near the equator and at high pressure, air descends at 30º which causes high pressure preventing cloud formation, leading to persistent dry conditions
