W - 2.5 -> 2.7

Question 1

Houston, Texas:

Answer 1

• 4th most populous city in USA (2.3 million)
• located on banks go buffalo bayou river
• economy based on energy industry, biomedical research and aeronautics
• august 2017 - hurricane Harvey caused severe flash flooding - 50 inches rain
• more people die here from flooding than anywhere else in USA

Question 2

what caused UK floods in 2020

Answer 2

• a succession of 3 ‘named’ storms - Ciara, Dennis and Jorge
• 350% of typical annual rainfall - creating very were antecedent conditions, saturated soil, overland flow
• Deep low-pressure mid-latitude depressions stalled over the UK in November
• Large areas of the River Severn floodplain have been built on for housing, along with lots of deforestation

Question 3

socio economic impacts

Answer 3

• 40 people were evacuated from Ironbridge
• Homes were inundated – damaging furniture and high-values goods
• Factories can be cut-off from infrastructure
• Shop stocks are ruined
• Some homes / shops cannot get flood insurance again.

Question 4

Environmental Impacts:

Answer 4

• Floodwater can degrade the soil and ecosystems: :
• Intense flooding can bring eutrophication
• Pollution from sewage: nitrates, chemicals, heavy metals – all degrade aquatic habitats, and poison soil ecosystems (moles, voles, hedgehogs, badgers
• Animals are often cutoff in isolated fields, or drown.
• New crops / seeds cannot be planted / delayed – price of food starts to rise.

Question 5

precipitation

Answer 5

• Could be more intense, further around the world
• Tropics will get more rain,
• S-Africa and S Europe will get less
• N Europe – less snow, more rain

Question 6

run off

Answer 6

• 1oc rise = runoff 40%
• Accelerated cycles of intense rainfall and less infiltration
• More droughts in between.
• Lakes and reservoirs drying up?

Question 7

evaporation

Answer 7

• More in Asia and N America
• More over oceans
• More cloud cover counteracts evaporation
• More productive vegetation (more transpiration)
• Lesson water in soil

Question 8

soil moisture and GW

Answer 8

• Depends if precipitation counteracts this.
• GW depends more on human abstraction

Question 9

permafrost

Answer 9

• High latitude temperatures increase, permafrost degrades
• Active layer deeper and methane release (affects GW supply and trigger feedback cycle

Question 10

snow/ice

Answer 10

• Snow-cover duration falls, spring-melt earlier
• More river water in ST, less in long-term
• More pronounced in high-altitude glaciers

Question 11

thermal expansion

Answer 11

of lakes as a result of climate change

Question 12

excess soil moisture

Answer 12

lower rice yields + soy beans

Question 13

increased transpiration

Answer 13

depletes soil moisture

Question 14

hydropower reservoirs

Answer 14

increases GHG emissions - net negative?

Question 15

higher heat in freshwater ecosystems

Answer 15

= minimal water flows = changes wetlands by changing breeding/ feeding tendencies

Question 16

2015houston floods

Answer 16

16 dead
1 billion loss
Social riots

Question 17

Human causes in Houston

Answer 17

• urban development = only 25% of 600k previously of prairie grass acres, which are designed to absorb significant amounts of water
• 30% of freshwater wetlands are gone

Question 18

Physical causes in Houston

Answer 18

• some scientists do claim that climate change has increased the frequency if 1/100 events due to increased unpredictablity and variations in climate