Water and Carbon Cycles

Question 1

What is the annual rainfall and evapotranspiration in Pickering and what impact does this have on the river regime

Answer 1

Rainfall of 978mm and evapotranspiration of 540mm. River won’t run dry at any point in the year - increased flood risk

Question 2

What soils are in the moorland of Pickering and what is the impact of this

Answer 2

Shallow, peat soils - easily waterlogged - increased flood risk

Question 3

What is the moorland of Pickering used for and what is the impact

Answer 3

Pastoral (cow) farming - compress soil, making it impermeable - increased flood risk
Cows release methane - increased CO2 in atmosphere - less rainfall in long term - decreased flood risk

Question 4

What happens to the geology of Pickering in the winter and what impact does this have

Answer 4

Water table is high - permeability of sandstone and gritstone is diminished - increased flood risk

Question 5

What vegetation is in the upland of Pickering and what impact does this have

Answer 5

Heather, bracken, grasses and scattered trees - don’t intercept much water - increased flood risk

Question 6

What is the relief of Pickering and what impact does this have

Answer 6

Upland areas 200m above sea level, lowland areas around 35m above sea level - steep - water can flow down quickly and build up valleys - increased flood risk

Question 7

What is the nature of Pickering’s roads and what impact does this have

Answer 7

Urbanisation - tarmacked roads - impermeable - increased surface runoff - increased flood risk

Question 8

Pickering Beck - Slowing the Flow - bunds

Answer 8

Large flood storage area constructed upstream. Can store up to 120,000 cubic metres of floodwater and releases it slowly. Will provide 90% of the storage needed

Question 9

Pickering Beck - Slowing the Flow - leaky wood dams

Answer 9

167 dams of logs and branches placed in streams. Let normal flows through but restrict higher flows

Question 10

Pickering Beck - Slowing the Flow - heather bale dams

Answer 10

187 heather bale dams placed in drains and gullies constructed in 60s/70s. Enabled moorland to store more water

Question 11

Pickering Beck - Slowing the Flow - afforestation

Answer 11

44 hectares of woodland planted in the catchment. Will help intercept and store greater volumes of water

Question 12

Pickering Beck - Slowing the Flow - Success?

Answer 12

Reduced risk of flooding from 25% chance to 4% chance
Cost £2 mil
Christmas 2015 - measures reduced the flood peak by around 20%

Question 13

Amazon Rainforest - background

Answer 13

Annual rainfall 2000+mm. 27C temps throughout the year - ideal for plant growth
Home to 200mil people and half the worlds species of plants and animals
Trees absorb huge amounts of CO2 (wood is about 50% carbon) and emit 28% of the worlds oxygen
Soil is an important carbon store

Question 14

How much of the Amazon is being deforested each day and why

Answer 14

6 football pitches
Because of commercial farming, mining, logging, and settlements

Question 15

Impact of deforestation in the Amazon on the water cycle

Answer 15

Less interception - more overland flow, runoff rates increase - more risk of flooding
Less trees - soil exposed to sun - soil erosion
Forests emit salts and organic fibres as well as water when they transpire - act as condensation nuclei and assist in cloud formation. Less trees = less rainfall

Question 16

Impact of deforestation in the Amazon on the carbon cycle

Answer 16

Slash and burn - natural vegetation cut down and burned - climate change = more wildfires (positive feedback loop). CO2 from trees returned to atmosphere, less photosynthesis, rain washes ash into the ground and increased carbon content of soil
Selective logging of mahogany - damages neighbouring trees, leading to open gaps in the forest - more exposed to sunlight and wind. Dry quickly - more frequent wildfires
Forest scrub that replace primary forest store 40% less carbon