Physical Geography Case Studies

Parts of south Asia flood most years due to:

• Monsoon Climate (80% of rain in 4 months)
• Low-lying land (e.g. in Bangladesh, 90% of land is less than 10m above sea level)
• Melting snow and ice from the Himalyas

Physical Factors:

• Monsoon after a very dry, early summer.
• Heavy and prolonged rainfall
• Peak discharges of two rivers (Ganges and Brahmaputra) coincided.

Human Factors:

• Deforestation in Nepal and the Himalayas.
• Growth of urban areas (due to migration)
• Collapse of old earth dams.

Social Impacts:

• 2,000 died (reluctance to evacuate, can't swim, poor transport links)
• Polluted wells caused 100,000 to catch water-borne diseases.
• 25 million homeless
• 112,000 houses destroyed in India (porous mud bricks became saturated).
• Dhaka (capital of Bangladesh) was inundated.
• 4,000 schools affected, 44 totally destroyed.

Economic Impacts:

• US $1 billion.
• Factories closed (loss of raw materials) - many poor became unemployed.
• Loss of livestock (reliance on agriculture)  + flooded fields caused low rice crop.
• Individual and national debt increased.

Environmental Impacts:

• Rivers polluted with sewage, but fertile silt deposited on flood plain.

The River Eden reaches the sea near Carlisle and flooded due to:

• Large drainage basin
• Steep sided basin
• Many fast draining streams

Physical factors:

• Heavy rainfall
• Rain fell on saturated ground
• High peak discharge

Human factors:

• Large built-up area with impermeable concrete and tarmac surfaces
• Little soil or vegetation 
• Drains and sewerage systems overflowed in some areas

Social Impacts:

• 3 died
• 3000 made homeless for up to a year - temporary accommodation disrupted lives 
• Personal possessions damaged
• 4 schools severely flooded 
• Increase in stress-related illness

Economic Impacts:

• £100 billion
• 350 businesses shut down 
• 'United Biscuits' - 33/1100 employees lost their jobs
• 70,000 addresses lost power
• 80 buses destroyed and many roads and bridges damaged

Environmental Impacts:

• Increased river bank erosion
• Rivers polluted with rubbish and sewage

Hard Engineering Strategies:

• Many dams, including Three Gorges Dam - reservoir catches water and slowly releases it, largest HEP station in the world
• Many levees

Positive Effects:

• Reduced major flooding from 1 in 10 years to 1 in 100 years
• Produces a lot of electricity (3% of China's demand)
• Safer to navigate up the river - increase in river shipping

Negative Effects:

• People have had to relocate (2 million)
• Reservoir will flood farmland, factories etc.
• If dam fails, catastrophic flooding could occur
• Destroys habitats and endangers species
• Doesn't protect everyone - increased risk of flooding elsewhere

Soft Engineering Strategies:

• Gravel soakways
• Low value land allowed to flood
• Planning/Land-use restrictions
• Local Flood Warning Plan - 25 Hour Floodline
• Internet advice
• Voluntary flood wardens

Damage is reduced - Floods still happen:

• Difficult to measure success
• Flood warnings were issued in 2008
• Ock flood plain wan't flooded, but the Thames flood plain was
• The 2008 floods did less damage than in previous years (no lives lost)

Unique environment:

• Wilderness area - unaffected by large-scale human activity
• Contains 90% of all ice on Earth 
• Ice sheet covers most of Antarctica all year round

Fragile Ecosystem:

• Little available water for plants to grow
• Very cold - Average of -49 degrees C + very little sunshine
• Very few plants and animals can survive there - there is abundant bird/sea life
• Takes a long time to recover from any damage
• Sea ecosystem is also fragile (food chain easily affected by one species)

Valuable resources:

• 300 species of fish, 8 species of whale
• Attractive scenery
• Large underground deposits of coal and iron ore, large oil reserves

Antarctic Treaty:

• Set up in 1961 - 12 countries came up with laws to protect it
• Includes many protocols and conventions that control or prohibit certain activities

Oil Extraction, Mining and Whaling:

• Oil extraction and mining are currently banned
• 'Madrid Protocol' of 1998 - ban is in force for 50 years (may be lifted in 2048)
• In 1994 the Antarctic was declared a whale sanctuary and commercial hunting was prohibited (some allowed for scientific research)

Sustainability:

• In 2007-2008, 46,000 tourists visited the area
• 5,000 scientific researchers there in the summer, 1,000 in the winter - 'Protocol on Environmental Protection' - scientists must remove waste etc.
• 'Convention for the Conservation of Antarctic Marine Living Resources' - quotas on fish catches (e.g. krill)