Exam Questions Flashcards
Explain concept of dynamic equilibrium in water cycle
It refers to the balance between the continuing processes within the hydrological cycle.
Hydrological system is a closed system meaning no inputs of water or outputs of water leave system - it’s simply recycled.
The drainage basin (area drained by river/ tributaries) has both inputs and outputs which are subject to change - meaning it’s an open system where matter and energy can be transferred into and out of system.
Dynamic equilibrium can be upset easily through extreme events such as droughts / storms / human activity which could lead to issues like flooding
what is meant by water balance
State of balance / equilibrium between the inputs (precipitation) and outputs (evapotranspiration) within the drainage basin.
Formula (P= Q + E +/- change in stores)
The river regime also shows the variability of discharge through out the year in a river.
Eg uk has a temperate climate with seasonal variations. More precipitation in winter months leads to a surplus and in turn during summer months ET exceeds precipitation leading to an eventual deficit.
To what extent does the carbon budget refer to ?
Balance of exchanges between 4 major stores of carbon
Describe one impact of climate change upon global precipitation.
Temps rise leading to evaporate from water - oceans.
Meaning atmosphere hold more water vapour.
Higher amounts of rainfall in places.
More intense burst
Outline potential impacts of farming practices upon water cycle.
Farming practices include deforestation, soil drainage and irrigation which all impact water cycle to great extent.
Deforestation is the removal/ clearance of trees as seen in Amazon rainforest. This impacts WC as less trees means less interception of rainfall so less water stored in biosphere. In turn meaning transfer of water through overland flow / surface run off. This will lead to flooding and flashy hydrograph.
Soil drainage also impacts WC. It’s the insertayion of drains which increases the speed of through flow in soil meaning more water reaches channel flow quicker - flooding / peak discharge reached quicker - flashy.
Irrigation methods divert water and can cause water to leave river basin which would inturn mean less discharge in the river - less storage.
Name a natural cause of variation in water cycle?
Storm events transfer significant amounts of water from atmosphere store to hydrosphere and lithosphere stores.
Outline role of positive feedback in water cycle
Positive feedback is when the effects of an action are amplified - upset equilibrium.
For example, global temps rise due to more co2 being suspended in atmosphere from burning fossil fuels.
This subsequently warms the oceans in hydrosphere.
Water then obtains more energy which will lead to more evaporation from ocean surface into atmosphere.
Water vapour leaves hydrosphere and goes into atmosphere.
In turn eventually leading to more precipitation and enhances the greenhouse gas effect and warming.
A sentence to summaries an example of positive feedback between carbon cycle and climate change.
Increase concentrations of atmospheric carbon dioxide leads to global temp rise.
Warming the ocean.
Which absorbs led co2 from atmosphere.
So atmospheric co2 increases.
Also the fact more evaporation from ocean means more water vapour suspended in atmosphere contributing to warming
Outline the role of wearing in carbon cycle.
Outline potential impacts of human intervention in carbon cycle.
Outline potential impacts of human intervention in carbon cycle.
Humans can have both positive and negative impacts on carbon cycle.
Negatively, we have exacerbated the amount of carbon dioxide in the atmosphere through burning fossil fuels through combustion. This is because we are directly release information co2 into atmosphere. Ultimately adding to the green house gases effect and contributing to climate change - positive feedback.
However, mitigation strategies generally have positive impacts. Like carbon sequestration. This is done through transferring co2 from atmosphere and storing it in long term storage whether this is oil/ coal reserves/ deep ocean. This results 90% of co2 from burning fossils fuels to be captured so In turn reducing co2 in atmosphere. Nullifying greenhouse effect / warming.
(Deforestation)
Explain concept of negative feedback in relation to carbon cycle.
Negative feedback occurs when events of an action are nullified rather then amplified - promoting equilibrium.
Eg in arctic ice is melting through both natural/ human impacts one of which is the combustion of fossil fuels which causes more co2 in atmosphere and enhances greenhouse warming effect.
As the ice melts latent heat means moisture is released Into atmosphere which creates thick cloud. This cools the atmosphere blocking more sunlight from hitting directly upon ice. This ultimately means less melting of the ice and.
Overall, this negative feedback loop impacts carbon cycle as provides cooler climate meaning less melting.
Evaluate the views that human activity is having a greater impact that natural factors on carbon cycle
Human ————- •deforestation •urban growth •water abstraction
Natural ————- •amount/intensity of precipitation •el niño •drought •vegetation
Both combine to produce greatest impacts.
Often human exacerbate natural issues
Asses the impact of natural changes to carbon cycle.
Wild fires - small extent as equilibrium is reached again
Volcanoes - small extent but in past was larger
Natural temp change - larger impact
Asses the extent to which human impacts have changed carbon cycle stores
Deforestation changed biosphere store and then atmosphere store
Combustion of fossil fuels changed atmosphere then cryosphere store.
Transport/ farming / urban growth /
