Water & Carbon Cycles

Question 1

Outline the process of infiltration as a flow of water within a
drainage basin system. [3 Marks]

Answer 1

• Infiltration is the downward movement of water from the ground surface to the soil.
• The rate of this flow can be limited if the soil is saturated.
• Soil characteristics (mainly porosity) affect the rate of this flow.

Question 2

What is acidification

Answer 2

It’s the reduction of PH (making an ocean more acidic), due to dissolving carbon dioxide from the atmosphere.

Question 3

What is Afforestation? & How does it affect the water and carbon cycle

Answer 3

Deifintion: the planting of vegetation and trees with the aim of covering bare land.

Water Cycle: It reduces flooding, as plants and trees take up and store water, and increases the flow of transpiration.

Carbon Cycle: Increases stores of carbon for the biosphere, and decreases stores of carbon for the atmosphere. Once this vegetation dies, this increases stores of carbon in the pedosphere.

Question 4

What is a flux? Give 1 example each from the water and carbon cycle.

Answer 4

A fancy name for a transfer. In the water cycle, a flux or transfer may be infiltration and in the carbon cycle - it may be acidification.

Question 5

Give examples of 2 natural processes that can alter the magnitude of stores in the carbon cycle?

Answer 5

Wildfires & volcanic activity

Question 6

How does a volcanic eruption contribute to the carbon cycle?

Answer 6

• It alters the magnitude of the lithosphere’s carbon stores, and the eruption acts as a transfer of carbon between here and the atmosphere.
• Carbon is stored within the earth in magma, this is released during an eruption. The majority of carbon enters the atmosphere as CO2.
• Recently, eruptions have released much less CO2 than human activities. Still, a large eruption has potential to disrupt the carbon cycle significantly.

Question 7

How does a wildfires contribute to the carbon cycle?

Answer 7

• They rapidly transfer large quantities of carbon from biomass (or soils) in the pedosphere/biosphere, to the atmosphere. Loss of vegetation decreases photosynthesis, meaning less carbon is removed from the atmosphere.

Question 8

Why can wildfires actually be a good thing?

Answer 8

They sometimes encourage growth of new plants, which takes in carbon from the atmosphere via photosynthesis. Depending on the amount and type of regrowth, fires can have a neutral effect on the amount of atmospheric carbon.

Particular conifers also rely on wildfires, some have pinecones that are only activated when temperatures rise due to a wildfire. Such pinecones often burst open, due to the extreme temperatures of a wildfire, meaning millions are scattered - and can travel distances in the hot air, starting new forests.

Question 9

What major event market a HUGE increase on the impacts that humans have on the carbon cycle?

Answer 9

The industrial revolution.

Question 10

What particular stores are we seeing a rapid transfer from (of Carbon)?

Answer 10

Lithosphere & biosphere to atmosphere, faster transfer than natural

Question 11

How can land use changes affect the carbon cycle? (don’t include FARMING, that’s included in my agriculture question)

Answer 11

Change of land from natural/agricultural (farmland) to urban is a major source of carbon.
- Vegetation is removed to make way for buildings and infrastructure (foundations), reduces biosphere stores - these transfer to atmosphere.
- Concerete production for surfaces, and use of machinery in building releases lots of CO2. Lithosphere to atmosphere.

Question 12

How can hydrocarbon extraction / fossil fuel extraction (same thing) affect the carbon cycle?

Answer 12

Extracting and burning (combustion) of fossil fuels releases CO2 into the atmosphere.

Without human intervention, the carbon would remain sequestered (stored) in the lithosphere for thousands/millions of years to come.

Question 13

How can Agriculture (same thing) affect the carbon cycle? Also, how has an increased population meant that farming has become a big contributor?

Answer 13

• Animals release CO2 and methane into the atmosphere with digestion and respiration.
• Ploughing can release CO2 stored in soil.
  Growing rice in rice paddies released methane.

As the world’s population has increased, there’s been an increased need for food production. As a result, farming practises have increased. Mechanisation for farming has also increased CO2 emissions.

Question 14

What’s the carbon budget?

Answer 14

The difference between inputs of carbon into a subsystem and outputs from it (a subsystem = biosphere, lithosphere, etc…)

Question 15

Are the spheres in the carbon cycle in balance with eachother?

Answer 15

No sphere is in balance with any other.

Question 16

What are the main sinks in the carbon cycle. And what is the main source?

Answer 16

Sinks: Biosphere, hydrosphere, pedosphere & Source: Lithosphere.

Question 17

How does the carbon and water cycle interact [4]

Answer 17

-1 Carbon Dioxide & Water are both needed for photosynthesis. [1]
-2 Both are also released during volcanic eruption [1]
-3 Increasing concentrations of CO2 (and Methane) mean that a global warming effect occur. [1] Due to this, levels of precipitation may rise - due to more evaporation of water vapor. Alternatively, in high pressure areas, these high levels of evaporation could contribute to arid land.
-4 Decomposition requires CO2 and water (For decomposers - i.e. Fungi to live - damp conditions)
-5 Melting of permafrost (releasing water) can lead to increased atmospheric levels of CO2.

Question 18

What is the reflection of the sun from the earth’s surface known as? How is this affected by global warming.

Question 19

What is the movement of water around the oceans known as?

Answer 19

Thermohaline circulation: salt makes water heavier; sinks to bottom; cold water heavier; sinks to bottom; global warming will interupt this, less saline water and warmer > flow disrupted.

Question 20

How much are sea levels rising each year?

Answer 20

around 3mm

Question 21

How much is sea level predicted to rise by end of this century?

Answer 21

around 0.8m

Question 22

What 2 factors cause sea level rise?

Answer 22

Terestrial Ice Melting: Due to global warming, higher surface temperatures, ice melts > positive feedback > leads to more temperature increase as more bare land means more absorption.

Thermal expansion: when the sea warms it expands.

Question 23

What type of feedback is caused by changes in albedo and why?

Answer 23

Positive: Less ice and more sea, lowers albedo, more heat absorbed so oceans become warmer (oceans have higher albedo - ability to absorb sunlight).

Question 24

Why is ocean acidification a problem?

Answer 24

Releases Hydrogen into the water that means it attracts towards carbonate, which results in biocarbonate, animals can’t use this to make their shells. More energy eeded to get calcium, shells are thinner and pitted (dissolved by acidic ocean) > coral reef loss.

Question 25

As arctic ice melts why is conflict more likely?

Answer 25

As ice melts, resources (fossil fuels - 30% of gas resources in world) are accessible, confilct over who owns the water due to continental shelf in Lomonsov ridge.

Question 26

Rainfall and temperature of rainfall:

Answer 26

2000mm and 27 degrees

Question 27

Why is the rainforest important?

Answer 27

Absorbs large CO2 amounts & emits 28% oxygen.

Question 28

How many live in rainforest?

Answer 28

200m people.

Question 29

Explain rainforest carbon cycle:

Answer 29

ITCZ is overhead, therefore water will evaporation, heavy convenctional daily rainfall occurs, interceptions occurs, then evapotranspiration off leaves. Infiltration into the soil, stem flow to reach this. Throughflow may occur. Or runoff if ground is saturated. 25% immediately evaporated back to atmosphere, 75% interception and continues down the cycle. 50% of this transpires or runoff/infiltration.

Question 30

Impacts of human activity on rainforests? (explain how deforestation affects it).

Answer 30

Over half of all tropical rainforests have already been cut down.

0 RUNOFF: daily convectional rainfall, as less interception of rainfall > compacts the soil > infiltration can’t take place > more runoff occurs.

EVAPORATION/TRANSPIRATION INTERUPTED: no transpiration, as less plants. No surface to evaporate off. Water runs off and goes to river instead. Interupts precipitation > less precipitation > drier and uninhabital for animals.

NO NUTRIENTS: Less nutrients > weaker soil > everything gets washed away > greater erosion> this soil enters the rivers.

AIR DOWNWIND: Air that passes over extensive amount of forest for a few days produced twice as much rain as air that has passed over little forest. (as it carries less moisture to the forested areas - cutting down an area of forest can reduce levels by 20% of rainfall downwind).

Question 31

What’s mitigation?

Answer 31

The reduction/inhibition of risk

Question 32

Where are rainforests mainly located?

Answer 32

Along the tropics, as the climate is hot and moist (preferred for growth).

Question 33

Why are hot, wet climates so good in the rainforest?

Answer 33

Result in rapid plant growth.
And rapid decay > carbon cycle is accelerated, and nutrients are quickly released into the soil, then taken up quickly by plants > further growth

Question 34

Give examples of mitigation in case study indonesia:

Answer 34

a) zoning of high value areas in spare forests.
b) expanding production on non-forested land.
c) Sea wall construction.
d) Reconstruction of city in Boreno

Question 35

Impacts of deforestation in Jakarta (Indonesia case study)

Answer 35

Risk of flooding, aquifiers depleted and not recharged, sinking by 10cm.

Question 36

What are the factors driving change in the hydroshphere of carbon?

Answer 36

Diffusion, ventilation, calcification, compaction, photosynthesis, respiration

Question 37

Human factors which impact change in the carbon cycle over time?

Answer 37

deforestation, change in land use, agriculture

Question 38

Where is the River Exe found in Britain? Case study for water and carbon

Answer 38

The location is South West of Britain. Its source begins in North Exmoor, making its way down to the lower course (mouth) at Exmouth.

Question 39

What is the river exe’s catchment area generally like?

Answer 39

high relief near the source. then a decrease in the middle and lower course of relief. Length is just over 80km. Many tributaries (high drainage density)

Question 40

What is the relief of the river exe’s catchment area like?

Answer 40

Upper course near mouth is high relief, quickly decreases to low relief for middle and lower courses. Exmoor is 500m above sea level (source)

Question 41

What is the geology of the river exe’s catchment area like?

Answer 41

The geology is impermeable rock (quick runoff), sandstones.

Question 42

What’s the land use of the river exe’s catchment area like?

Answer 42

67% agriculture.
15% woodland.
3% Moors and peatbogs. (high water store)

Question 43

What’s the significance of peat bogs in the river exe?

Answer 43

They are a form of carbon sequestration.

Question 44

What’s the water balance?

Answer 44

Dynamic equilibrium. Outputs and inputs are equal (outputs = evapotranspiration ; inputs = evaporation).

Question 45

What’s the water balance like in River Exe?

Answer 45

Majority is running off, as ground is impermeable (844mm) , total rainfall (1295mm), evaporation/soil water storage (451mm)

Question 46

Give an example of human intervention in the River Exe?

Answer 46

1979 River Haddeo (a tributary of the Exe) was dammed. Creating a Reservoir.

Question 47

what’s the impact of the damming of the \river haddeo tributary

Answer 47

River regime graph becomes flattened > as flow is regulated.

Less chance of flooding downstream, as flow is regulated

Dry summers > water is released downstream to support treatment works downstream.

Water released to aid salmon migration downstream in spring.