Case Studies of Water & Carbon Cycles

Question 1

How long is the River Exe?

Answer 1

82.7km from Exmoor to sea at Exmouth (south Devon)

Question 2

What are the Physical Characteristics of the River Exe?

Answer 2

Upper Catchment area=601km^2
Max elevation=514m north
Min elevation=26m south

Question 3

What are the Geological Factors of the River Exe?

Answer 3

84.4% of catchment has impermeable rock under (Devonian Sandstone) = hi drainage network

Question 4

Outline the Land use of the River Exe?

Answer 4

67% = agriculture grassland
15% = woodland/arable farmland
3% = moors & peat bogs

Question 5

What has affected the Water Cycle of the River Exe?

Answer 5

1. Wimbleball Reservoir construction
2. Exmoor peatland restoration

Question 6

When was Wimbleball Reservoir Constructed and what did it do?

Answer 6

1979 - dammed River Haddeo

Question 7

What are the traits of the Wimbleball reservoir?

Answer 7

150ha
Regulates water flow
Stops water discharge peaks/troughs (reduce flooding risk)

Question 8

What happened in Exmoor to peat bogs?

Answer 8

Drained for suitable farming

Question 9

What were the 3 - impacts of draining peat bogs?

Answer 9

1. Hi H2O flow speed to Exe = low H2O quality as more silt downstream
2. Ugly scars left behind on land
3. C release from peat as CO2 & CH4

Question 10

How did the Exmoor Mires Project restore peat bogs?

Answer 10

Block drainage ditches with peat blocks/moorland bales

Question 11

What were 2 + impacts the Exmoor Mires Project had on the landscape?

Answer 11

1. Increased H2O content
2. Ground now saturated & boggy - retain C stored in peat

Question 12

What is the main aim of the Exmoor Mires Project?

Answer 12

Restore 2000 ha of Exmore to boggy conditions

Question 13

What were the results of the Exmoor Mires Project in 2015?

Answer 13

1. > 1000 ha peat moorland restored
2. Nearly 100km of ditches blocked = water table raised by 2.65cm & drained water reduced by 2/3

Question 14

Outline 3 benefits of the Exmoor Mires Project.

Answer 14

1. Improved water quality
2. More H2O/C storage
3. Improved grazing/water supply for animals

Question 15

How much does the Amazon Rainforest cover?

Answer 15

Covers 40% of South American landmass

Question 16

Outline the Amazon’s climate?

Answer 16

Hot and wet with dense vegetation

Question 17

Outline the biodiversity in the Amazon

Answer 17

1 million plant species
>500 mammal species
>2000 fish species

Question 18

What causes the Amazon to have a wet climate and what is an impact of this?

Answer 18

Cause: Atlantic Ocean has hi evaporation = wet air over Amazon
Impact: High rainfall

Question 19

What is an impact of warm temperatures in the Amazon?

Answer 19

Hi evaporation = increased precipitation

Question 20

What is the impact of the dense canopy in the Amazon?

Answer 20

High interception -> less H2O flow to rivers

Question 21

How has the water cycle affected the Amazon environment?

Answer 21

Species have adapted to high humidity/rainfall

Question 22

How is the Amazon a Carbon Sink?

Answer 22

Veg & soil stores a lot of carbon

Question 23

How has the high concentration of CO2 affected the Amazon?

Answer 23

Higher photosynthesis and Biomass

Question 24

What was another way CO2 impacted the Amazon?

Answer 24

High sequestration - important C store

Question 25

What is a negative impact of the high CO2 in the Amazon?

Answer 25

Trees grow quick, die young (Carbon Fertilisation) Can't rely as a C store

Question 26

How has deforestation affected interception in the water cycle?

Answer 26

No tree canopy -> too much water in soil -> surface runoff & flooding

Question 27

How has deforestation affected the evapotranspiration of the Amazon?

Answer 27

Low evapotranspiration -> fewer clouds & rainfall = drought

Question 28

How has deforestation affected the transfer of Carbon in the Amazon?

Answer 28

Less roots -> rain washes away -> C transferred to Hydrosphere

Question 29

How has deforestation affected soil absorbtion of C?

Answer 29

Less leaf litter -> no new growth of soil = less absorption

Question 30

How has deforestation affected the tree's impact on the C cycle in the Amazon?

Answer 30

Less CO2 absorption by trees -> higher global warming

Question 31

Outline the 3 impacts of Climate Change on the Amazon

Answer 31

1. Temperature increase -> droughts in 2005 & 2010 2. Plants/Animals die in dry weather & forest fires 3. 4 degree temperature rise -> kill 85% rainforest = decomposition release CO2

Question 32

How has Selective Logging limited human impact on the Amazon?

Answer 32

Some trees logged -> forest structure kept = regeneration

Question 33

Outline how replanting limits human impact on the Amazon

Answer 33

Replace cut down trees -> Peru planned for 3.2 million ha restoration by 2020 Same tree types used

Question 34

Outline how Environmental Laws limit human impacts on the Amazon

Answer 34

Ban excessive logging Ban unsustainable wood use Brazilian Forest Code = landowners keep 50-80% of land as forest

Question 35

Outline 2 ways how Protection has limited human impact on the Amazon

Answer 35

1. National Parks/Nature Reserves (e.g Central Amazon Conservation Complex 2003 protects 49000 km^2 2. Logging in reserves/parks are monitored

Question 36

Outline 3 drivers of change in the Amazon

Answer 36

1. 2000-2007: 19,368km^2 deforesation/yr 2. Brazil: 75% CO2 emissions by deforestation 3. Slash & burn forest removal -> low cumulus clouds that don't rain

Question 37

Outline 3 facts about the Carbon Cycle in the Amazon

Answer 37

1. Stores 80-120 bn tonnes of C 2. Increase above-ground biomass by 0.3-0.5% per year 3. Losing capacity to absorb CO2

Question 38

Outline 3 facts about the Water Cycle in the Amazon

Answer 38

1. Annual discharge 15% of fresh water into oceans 2. Avg annual rainfall = 2,300 mm 3. 48% evapotranspirated falls again as rain

Question 39

Outline 3 impacts changes of rainfall, extreme rainfall events/seasonality has on rivers in the Amazon

Answer 39

1. Lower river discharge 2. Flash flooding 3. Destroy Amazonian H2O supply

Question 40

Outline 3 impacts of warming H2O temperatures on rivers

Answer 40

1. Kill temperature dependent species 2. Change biodiversity (intro new, kill old) 3. Low H2O-dissolved O2 concentrations = eggs/larvae die