Carbon and Water- Water Cycle

Question 1

What is a system?

Answer 1

A system describes the interrelationships (depend in each other) between living and non-living components within an environment such as a pond or forest. They generally are composed of inputs such as precipitation, stores such as water, outputs (processes) such as evaporation and photosynthesis is an example of a flow or transfer.
Systems help us understand the world around us and how energy is transferred between components of a system.

Question 2

Define positive feedback. Use an example from a woodland to illustrate this.

Answer 2

A cyclical (circle) sequence of events that amplifies or increases change. Positive feedback loops exacerbate (increase) the outputs of a system, driving it in one direction and promoting environmental instability. E.G. Woodland carbon cycle - Increased temperatures due to climate change cause melting of permafrost. Trapped greenhouse gases are released, enhancing the greenhouse effect, raising temperatures further.

Question 3

Outline how negative feed back can lead to falling temperatures

Answer 3

As it is a cyclical sequence of events that damp down the effects of a system. Increased surface temperatures lead to an increase in evaporation from the oceans. The leads to more cloud cover. Clouds reflect radiation from the sun, resulting in a slight cooling of surface temperatures.

Question 4

Define dynamic equilibrium

Answer 4

This represents a state of balance within a constantly changing system

Question 5

Explain how the water cycle can be closed

Answer 5

As an entirety (on Earth) it’s a closed system (only got flows and stores) as water is not lost to or gained from space

Question 6

Explain how the water cycle can be open

Answer 6

At a local scale such as a drainage basin (area where water will flow into a river), it’s an open system. Precipitation is an input and runoff to the oceans is an output. There are many components and stores, such as trees, built-up areas and soil. Flows and transfers include throughflow (water moving underground) and groundwater flow.

Question 7

Explain how the carbon cycle can be closed

Answer 7

The global carbon system is a closed system as there are no inputs or outputs in the system as a whole.

Question 8

Explain how the carbon cycle can be open

Answer 8

At a local scale such as a forest, it is an open system with both inputs (processes) and outputs. There are many components and stores, such as rocks, the oceans and atmosphere. Flows and transfers include photosynthesis and respiration.

Question 9

What are 4 characteristics of the global water cycle

Answer 9

• water is not evenly distributed….
• future wars may be over water….
• ownership of water if a “hot” political issue. For example, damming rivers in one country can have serious repercussions for others.
• 97.5% of water is saline (salty), and of the remaining 2.5% which is drinkable, half of it is stored as snow/ice…

Question 10

What are the 4 main stores in the global water cycle

Answer 10

• lithosphere (land)
• atmosphere (air)
• hydrosphere (liquid water)
• cryosphere (frozen water - snow and ice)

Question 11

What is an aquifer

Answer 11

An underground store of water

Question 12

What aquifer dominates South America

Answer 12

Guarani aquifer dominates S.America

Question 13

Explain the geological conditions needed for an aquifer to form

Answer 13

Permeable + porous rocks (chalk + sand stone)

Allow water through forming underground reservoirs

Question 14

What is the upper layer of saturated rock called? Outline 2 reasons why this may rise or fall?

Answer 14

Water table. May rise or fall due to groundwater flow, water abstraction or recharge (water flowing into rock).

Question 15

What is meant by a “fossil aquifer”

Answer 15

Desert aquifers formed 1000’s of years ago when climate was much wetter

Question 16

Describe the distribution of aquifers (3)

Answer 16

• found worldwide
• not a lot in Asia
• few found in Northern regions of the Northern hemisphere

Question 17

How long does water remain in rivers

Answer 17

Rivers (2-6 months)

Question 18

How long does water remain deep down in the ground

Answer 18

Groundwater deep down (10,000 yrs)

Question 19

How long does water remain in lakes

Answer 19

Lakes (50-100 yrs)

Question 20

How long does water remain in the ground (not deep down)

Answer 20

Shallow G.water (100-200 yrs)

Question 21

How long does water remain in glaciers

Answer 21

Glacier (20-100 yrs)

Question 22

How long does water remain in the soil

Answer 22

Soil water (1-2 mths)

Question 23

Explain the high precipitation at the equator

Answer 23

It occurs due to the warm air rising and then as it rises it cools and condenses causing rainfall

Question 24

Why does the UK have variable rain & cloud cover?

Answer 24

Due to it being located in between the Polar and Ferrel Cells, these cells don’t mix so we have variable rain and cloud cover

Question 25

95% of water is locked up in which 2 ice sheets?

Answer 25

Antarctica and Greenland

Question 26

How old is the ice in Antarctica and Greenland

Answer 26

400,000 years

Question 27

What does “ice calving” mean?

Answer 27

Ice breaks away from an ice store

Question 28

“The equilibrium line in glaciers is moving to ever higher altitudes.” What does this mean?

Answer 28

This where the equilibrium line marks the altitude where annual accumulation and melting are equal. With climate change the line is moving to higher altitudes, making glaciers shrink and retreat.

Question 29

What is through flow

Answer 29

Through flow - Water flowing through soil towards a river channel.

Question 30

What is infiltration

Answer 30

Infiltration - Transfer morning of water from the ground surface into soil where it may then percolate into underlying rocks

Question 31

What is percolation

Answer 31

Percolation - Water soaking into rocks

Question 32

What is interception

Answer 32

Interception - Water intercepted and stored on leaves of plants

Question 33

What is evapotranspiration

Answer 33

Evapotranspiration - The combined losses of moisture through transpiration and evaporation

Question 34

Which water store has the shortest residence time? Suggest one reason for this

Answer 34

Interception as it is still exposed to the elements (e.g. wind blowing it off)

Question 35

Why does groundwater have the longest residence time?

Answer 35

Because it has no where to run off to it can it can only evaporate

Question 36

Explain 2 ways in which humans can increase overland flow

Answer 36

Deforestation removes vegetation stored, reducing outputs such as transpiration, increasing overland flow. Urbanisation may prevent infiltration, causing more groundwater + overland flow

Question 37

Account for 1 climatological factor in altering stores in a hillside system.

Answer 37

Storms - intense rainfall increases amount reaching the ground, increasing the magnitude of storms

Question 38

What is the drainage basin hydrological cycle

Answer 38

This is basically a detailed version of the water cycle. It is also very similar to the hillslope water cycle.

The hydrological cycle describes the continuous movement of water above and below the ground within a drainage basin. The water can appear in various forms and the cycle has no beginning or end. Within a drainage basin, it may be viewed as an open system with inputs, outputs, stores & transfers/flows.

Question 39

Using examples, illustrate how soil those and rock type can affect the transfer and storage of water within a drainage basin

Answer 39

The rock type affects the storage and transfer because permeable rock means water can pass through it meaning more water stores and it has a lower runoff figure, but with impermeable rock water can’t pass through it so there is more transfer and runoff. If the soil is utilising the water there is less water as runoff so there is more storage than transfer

Question 40

Explain, using an example, how vegetation has an important impact on drainage basin systems

Answer 40

River Severn is a forest area unlike River Wye, study showed that the forest area had increased evapotranspiration rates, so less water flows into rivers

Question 41

What is a flood hydrograph

Answer 41

this is simply a graph that shows how quickly and by how much a rivers discharge (the volume of water in it) rises after a period of heavy rain. By drawing these we can make judgements in the characteristics of the basin in which the storm event has occurred

Question 42

Explain how changes in water storage in the East Anglian Fens has had implications for the carbon cycle

Answer 42

This occurs in dry weather (low water table) - Peatlands are thick deposits of decomposed vegetation which act as important carbon stores. Dry peat is frittle & vulnerable to erosion, which can form black clouds of peat (decayed vegetation) as wind whisks peat up into the air. The ignition of peat can release carbon reducing carbon stores. Releasing harmful carbon dioxide emissions into the atmosphere