Rivers case studies- Geography

Rivers case studies- Geography

1. The causes, effects and management of river flooding in an LEDC- Bangladesh floods

   • Causes
     • Monsoon climate brings very heavy rain and snow. Soils are leached and heavy runoff results in soil erosion.
     • Spring snow- melt results in soil erosion and a rapid increase in river discharge.
     • Deforestation meant less evapotranspiration, more runoff and faster soil erosion.
     • 80 percent of Bangladesh lies on a huge floodplain and delta, most of which is only 1m above sea level.
     • River silts raised the river bed which reduced the capacity of the channel resulting in increased likelihood of flooding.
   • Effects
     • Over two thirds of the land was covered with water.
     • 30 million people were made homeless.
     • Flooding destroyed 50 percent of the crops in flooded fields.
     • Bangladesh's exports industries saw a 20 percent decrease.
     • 400 clothing factories were forced to close.
     • Over 900 bridges were washed away.
   • Management
     • Long term flood responses
       • Build embankments along the river.
         • Would provide jobs for villagers because they would need people to build them.
         • They are expensive to build- which is hard for an LEDC who might not have a lot of money.
       • Link up to an emergency Flood warning system.
         • Quite expensive which is hard for an LEDC.
         • This would enable villagers to be warned before a flood would occur. This would let people prepare and have time to evacuate.
       • Sink new tubewells which would protect water supplies during flooding.
         • Ensure the supply of safe drinking water and reduce the risk of water borne disease.
   • Details
     • Flooded in 1998.

2. The causes, effects and management of river flooding in an MEDC- River Uck flood

   • Details
     • Is in the area of the drainage basin of the river Ouse
     • 17 million pounds damage to businesses.
     • 30 cars were damaged.
     • 700,000 pounds damage to houses.
   • Causes
     • Heavy rain on the night of the 11th October 2000 so the water overflowed the banks and caused a flood.
   • Effects
     • Social
       • People could not get to work.
       • No transport- roads and railway lines were blocked.
       • Risk to health because of contamination of water and sewage.
     • Economic
       • Lost money because water got into shops and buildings.
     • Environmental
       • Water and ground contamination with sewage.
       • Some animals were drowned.
   • Management
     • The Environmental agency built the flood protection scheme in the summer of 2009.
     • Electric sensors at Buxted and Hempstead Mill constantly measured the flow level. If the river is rising at a certain rate then an emergency plan is triggered- the ambulance service, police, fire service and the environmental agency would be contacted. Another trigger would be 20mm of rain which would make a gate close by the environmental agency.

3. One river valley and its landforms- River Tee and the High Force waterfall

   • Details
     • High force is 21 metres tall
     • High force is a waterfall and gauge with a very deep plunge pool at the base of the waterfall.