Distinctive Landscapes: Case Studies

Question 1

Facts about the Thames Basin

Answer 1

• 346km long
• Most densely populated river basin in the UK
• Source in Cotswold Hills
• 2nd Longest River in the UK

Question 2

Describe the Geology throughout the Thames Basin

Answer 2

Source = Limestone (impermeable, Jurassic rock)
Middle Course = Permeable Chalk after weak, less resistant Sandstone + clay
Rest of Course = Impermeable London Clay (up until North Sea)

Question 3

What are the Distinctive Landscapes along the River basin?

Answer 3

1) Goring Gap (valley, meanders + bridge)
2) The Source (floodplain, 110m , limestone)
3) Isle of Dogs (London, urban meanders)
4) Dartford Bridge (Estuary, large bridge)

Question 4

London’s Water + Thames Valley

Answer 4

• Driest region in basin, struggling demand for water
• 40% of water supply from groundwater in permeable chalk aquifer
• Use of boreholes to retrieve water from chalk

Question 5

Thames Meanders

Answer 5

• Large volume of water = energy for lateral erosion
• Water flows at varied speeds + energy, creating a meandering course

Question 6

River Terraces + Rejuvenation

Answer 6

• Rejuvenation = process of sea level falling + rising eroding floodplains
• This creates a new river terrace each time it occurs (old floodplain)
• River terraces found along Thames Valley east and west of London

Question 7

What are the causes of Flooding?

Answer 7

Human Activity:
- Deforestation
- Urbanisation
- River Straightening

Geology:
- Impermeable ground
- Relief
- River Straightening

Climate:
- Frozen ground
- Intense Rainfall
- Antecedent Rainfall
- Impermeable ground

Question 8

Causes of 2014 Thames Flood

Answer 8

• New artificial channel : Jubilee River, carried water into Wraysbury + Staines
• Saturated ground from months of Antecedent Rainfall
• Large Urban Areas (impermeable ground + stressed drainage system)
• Series of Atlantic storms: 487mm rainfall from Dec-Feb

Question 9

Impacts of 2014 Flood

Answer 9

• 5000+ homes and businesses flooded in Wraysbury + Staines
• £500 million cost of clearing up after flood
• Thousands of people evacuated + didn’t return for months
• Flooding stretched to Greater London : Shepparton, Windsor, Datchet

Question 10

Thames Barrier

Answer 10

• Cost £484 million to construct in 1984 (£1.5 billion in modern economy)
• Requires constant maintenance to protect central London
• Protects over £1 billion in nearby structures and buildings

Question 11

Barking Riverside

Answer 11

• Uses natural flooding to enhance landscape + flow over floodplain
• Green corridors + parklands to slow infiltration + increase natural water absorption
• £400+ million in construction of 20,000 homes, 5 schools, hospital + health services
• Hasn’t yet been tested by flooding, new residences currently unaffected

Question 12

Examples of Landforms along Jurassic Coast

Answer 12

• Sidmouth Cliffs
• Lulworth Cove
• Durdle Door
• Swanage Bay
• Old Harry Rocks (stack)

Question 13

What are the 3 kinds of Rock along the Jurassic Coast?

Answer 13

Triassic Rock
Jurassic Rock
Cretaceous Rock

Question 14

Affected Areas of the 2014 Winter Storm

Answer 14

• Damage to railway line between Exeter + Plymouth (2 month repairs)
• Rock falls at cliffs in West Bay (coastal retreat)
• Damaged buildings at Portland Bill, Chesil Beach
• Lyme Regis coastal defences maintained tourism industry