Geography Case Studies

Geography Case Studies

1. Coasts

   • Coastal Area and Landforms: Dorset coast
     • Swanage Bay and Studland Bay
       • Formation of Bays: Bays form when there is a discordant coast line. In between each hard rock headland is a layer of soft rock which gets eroded by the sea to form a bay
       • Formation of Old Harry's rocks: The sea erodes the foot of the arch and the roof becomes heavy and collapses. The isolated rock is a stack. Over time stack is undercut and collapses. A stump remains at Swanage/Studland bay.

2. Rivers

   • Bangladesh Floods, July-September 1998
     • Bangladesh was part of India in British Empire. Bangladesh is now separate, but is surrounded N, E and W by India. Part of Asia. In South, shares coastline with Bay of Bengal.
     • Causes
       • Human
         • Deforestation in the Himalayas, at the sources of Brahmaputra and Ganges rivers so less interception, more surface run-off.
         • Deforestation for fuel and grazing, so increased surface run-off.
         • In India, the Ganges has been diverted for irrigation, increasing deposition or silt and reducing channel capacity. In the rainy season water is let through causing floods
         • Rapid unplanned urban growth has added to the problem of flooding. Urban populations in Bangladesh have increased from 4% in 1951 to 35% in 2009 (estimate). The growth is largely made up of poor migrants who often live in vulnerable areas.
         • Bangladesh is an LEDC and so doesn't have much money to spend on maintaining flood defences and creating them
       • Physical
         • Increased surface run-off leads to soil erosion and more silt, raising river beds. The bed of the Brahmaputra is rising 5cm/year.
         • Bangladesh is 80% flood plain and delta makes it very susceptible to flooding.
         • Cyclones at sea create a storm surge.
         • Silt blocks river channels and creates islands, reducing carrying capacity of rivers.
         • Meeting of 3 huge rivers increases flood risk.
         • 70% of total land area is less that 1m above sea level-nowhere for water to drain to
         • Heavy monsoon rains causes summer flooding.
         • Melting of snow from Himalayas adds to volume in the warmer mouths
     • Effects
       • Human
         • Over 1300 people died.
         • Lack of access to medical care.
         • Roads and railways swept away and so aid and rescue distribution was difficult.
         • Over 20 million made homeless and many lost everything.
         • Contamination of water by sewage dead bodies/animals, lack of clean water resulted in spread of disease such as Typhoid and Cholera
         • 20% decrease in production of exports
         • 400 clothing factorises forced to close
         • Overall the floods cost the country over $1 billion
       • Physical
         • About 1/2 million poultry and cattle were lost
         • 668,529ha (hectares) of crops destroyed
         • Deposition of rich fertile soil onto land
         • Providing water for crops
         • 57% of land flooded
         • ≈2/3 of land was covered by water and Capital Dhaka, was ≈2m underwater
         • 2 million tonnes of rice destroyed
     • Responses
       • Small scale - The Preparedness Programme
         • Cluster village: village raised 2m above sea level. Village houses 25-30 families.
         • Raised homestead: individual homes raised 2m above sea level on earth banks. The earth banks are planted with grass to prevent erosion and grass takes up water.
         • Flood Shelter: ≈2ha of raised land where people can bring livestock. Each shelter has space for 100 families, has toilets and community room.
         • Rescue boats: located around areas most at risk from flooding, near flood shelters.
         • Radios: radios given to each preparedness committee: flood warnings can be issued and preparedness plan put into action.
         • + : Appropriate tech, cheap, easy
         • - : Short-term, need agencies and flood risk map, affect small no. people
       • Large scale - Dhaka Integrated Flood Protection Project
         • Embankments - Earth embankments built to hold back rising water and save lives.
         • Slope Protection - to reduce erosion of embankments and soil erosion, reduce flood risk.
         • Drains - Storm drains linked back to rivers so water has somewhere to go.
         • Sluice Gates - able to close channels when water rises and so create a sort of dam so people on the other side are safe
         • + : Large no. people, long term
         • - : Expensive, affordable to make/maintain? Dams damage environment