Water and Carbon Cycle - Knowledge Flashcards
What is a system?
a set of inter-related events or components working together to produce an outcome
what parts does a system consist of?
inputs, stores, outputs, flows
what type of system is the water cycle? Why?
a closed system water is neither created or destroyed on a large scale
what is a closed system?
energy is transferred beyond the system but not matter
what type of system is the carbon cycle? Why?
closed system carbon is neither created or destroyed, it just cycles
what is dynamic equilibrium? give an example?
when inputs and outputs are balanced when both constructive and destructive waves act on a beach, but the sediment remains broadly the same.
what are the five spheres of earth systems?
atmosphere, cryosphere, biosphere, lithosphere, hydrosphere
Complete the following negative feedback example; -increase in CO2 -increase in temperature -increased plant growth
- increased uptake of co2 from plants -reduced co2 in atmosphere
complete the following positive feedback example: -increase in temperature -increase in ocean temperature -dissolved co2 released from warmer oceans
-increase in co2 - further atmospheric warming
Of the worlds water, what percentage is ocean water and what percentage is freshwater?
97% ocean water 3% freshwater
Describe the distribution of the earth’s freshwater in each different stores? Clue; the answers are percentages
79% ice caps and glaciers 20% groundwater 1% easily accessible surface freshwater
what are the different flows in the water cycle?
-River channel flow - Surface run-off -Infiltration -Percolation - Through flow (driven by gravity) - Stemflow (interception) - Groundwater flow (
what is an aquifer?
saturated, permeable rock that groundwater can flow through
what is the water table?
the upper layer of saturated rock
what is a confined aquifer?
an aquifer that is trapped between both permeable and impermeable rocks. Hence, it is highly pressurised and not affected by drought conditions.
What is an unconfined aquifer?
A aquifer that includes the water table which is at atmospheric pressure and therefore able to rise and fall - hence it is vulnerable to change in drought conditions and due to water abstraction.
what are the stores in the water cycle?
Lithosphere hydrosphere cryosphere atmosphere
Which store does water remain in for the longest?
Deep Groundwater (up to 10,000 years) Ocean (around 3000 or more years)
How long does water remain in glaciers?
20-100 years
which stores hold water for the shortest amount of time?
atmosphere - nine days soil water (1-2 months) rivers - 2-6 months
What is water vapour?
the most common form of atmospheric water which absorbs and reflects incoming solar radiation. It is a greenhouse gas!!!
does warm air or cold air hold more water vapour?
warm air holds more water vapour
How can climate change cause an alteration in the magnitude of water cycle stores?
at the peak of the last ice age the magnitude of cryospheric stores increased. In warmer periods the magnitude of the hydrosphere and atmosphere increases.
Complete this positive feedback loop: - rising sea levels - melting ice shelves
- further rise in sea level
what is evaporation? what is evapotranspiration?
the physical process of liquid becoming a gas - heat energy is needed and transpiration is when liquid is lost from a plant’s stomata. Precipitation occurs when the air reaches its maximum water carrying capacity.
what is condensation?
the physical process whereby gas and water vapour become a liquid. It occurs when air cools and it less able to hold water vapour (known as the dew point). Condensation contributes to the formation of clouds. Precipitation occurs when air can no longer hold the condensed water
what is adiabatic cooling?
when the volume of air increases as it rises and expands but there is no addition in heat - this leads to precipitation
what is orthographic rainfall?
adiabatic cooling - when air is forced to rise over hills and mountains and cools to produce precipitation - the shelter of hills and mountains leads to rainfall only on one side
what is frontal rainfall?
when air masses of different temperatures meet, the warm air rises over the cool sinking air and produces precipitation
what is convectional rainfall?
when warm air rises from hot surfaces on a sunny day
what is accumulation?
inputs into the glacial system due to snowfall
what is ablation?
the outputs of the glacial system due to melting
what is sublimation?
ice changing directly into water vapour
how do storms impact upon the hill-slope water cycle?
intense rainfall infiltrates into the soil less so there is more surface run off - the water reaches the river channel faster and there is more flooding. Less water vapour is held in the atmosphere as intense rainfall takes place.
what is the soil water budget?
the balance of water in a defined area
what happens to the soil water budget in wet seasons?
precipitation exceeds evapo-transpiration so there is a water surplus - ground stores fill with water, more surface run off, higher discharge + river levels rise.
what is river discharge?
the volume of water flowing through a river channel
what happens to the soil water budget in dry seasons?
evapo-transpiration exceeds precipitation so there is a water deficit - ground stores are depleted, there is less surface run off and river levels fall
how does farming impact upon the hill-slope water cycle?
farmers use artificial ditches to drain the land - by improving drainage in poorly drained areas productivity can be improved as soil is aerated and the structure improves. However, this can lead to more through flow and surface run off which increases river discharge and flooding.
more crop cover increases the interception and reduces surface run off
why is the quality of groundwater in coastal areas less reliable?
intrusion of salt water from the sea degrades groundwater and leads to difficulties in using it domestically or for agriculture.
how does urbanisation impact upon the hill-slope water cycle?
impermeable surfaces reduce infiltration and increase the likelihood of flooding
how does deforestation impact on the water cycle?
More water leaves through the channel as less is recycled into the atmosphere through evapo-transpiration. A reduction in water vapour in the atmosphere leads to falling levels of precipitation. River levels fall in the long term. there is less interception and as a result water reaches the river channel faster
what is a drainage basin?
an area of land drained by a river and its tributaries..
what is the watershed?
the boundary between drainage basins
is the drainage basin system an open or closed system?
it is an open system as it has inputs and outputs of both matter and energy
what are the inputs, outputs, and flows in the drainage basin system<
how is water stored in the soil?
pore spaces between soil particles fill with air and water.
describe the soil water budget:
what is discharge measured in?
cumecs
what is a river regime?
the annual variations in the amount of discharge in a river in response to climatic factors and drainage basin characteristics.
what is the lag time on a flood hydropgraph?
the amount of time between the peak rainfall and the peak discharge - it indicates how quickly precipitation reaches the river channel
what is the rising limb?
the part of the hydrograph that indicates how quickly a river responds to a storm event?
what is the falling limb on a hydropraph?
The part of the hydrograph that indicates how a river returns to its base flow after a flood event
would you like to see a hydrograph to study?
Yes, certainly!
what is a flashy hydrograph?
short lag time, high peak, steep rising and falling limbs
what is a subdued hydrograph?
long lag time, low peak rainfall, gently rising and falling limbs,
how does the drainage basin shape affect the response of a river to a storm event?
a circular shape is more flashy because water reaches the channel at the same time
how does the geology of a drainage basin affect the response of a river to storm events?
impermeable rock = more overland flow, less throughflow and less infiltration. = a flashy response.
How does vegetation affect the response of a drainage basin to a storm event?
thick vegetation results in greater interception which slows water accessing the river channel.
evapo-transpiration will also reduce how much water gets into the river which makes the hydrograph more subdued.
how does ground saturation affect the response of a drainage basin to a storm event?
prior rainfall saturates the soil and increases overland flow whilst reducing inflitration