River Rhine Floods

River Rhine Floods

1. Effects of flood in 1995

   • 1 dead
   • 250,000 people and millions of farm animals evacuated
   • City centre of Cologne flooded to a depth of 2 metres
   • Lots of Looting (stealing)
   • Schools flooded
   • People out of busniess

2. Causes

   • Human
     • Meander bends straightened to improve navigability and speed flow. River 100 km shorter and 30% faster as a result.
     • One-third of Holland is below sea level and the drained polders have shrunk, lowering them below the river level in some places
     • Changes in farming practices have reduced floodplain storage
     • Levées built for better flood protection (almost like a straight jacket)
     • Ploughing
   • Physical
     • Sediment carried downstream is deposited and has built up the channel bed, in places higher than the level of the land.
     • Abnormally high rainfall over 3 months: the wettest January on record
     • high spring temperatures caused early snow melt in the Alps - two months earlier than normal

3. Management

   • Contour ploughing
   • Flood proofing
   • Flood retention basins, (store water at times of flood risk)
   • Strengthening levées
   • Afforestation
   • Lifting things on the ground floor off the floor of the house
   • Tilling downstairs of the house