Human Interaction with Rivers

1
Human Interaction with Rivers

• River very important to people and have attracted
  settlement for a number of reasons including
• Water supply and fish
• Fertile Flood plain
• Transport and trade artery
• Defence
• Bridging points

2
Controlling Rivers

• Building dams and reservoirs to hold water and
  generate power
• Changing the course of rivers-straightening
  meanders to allow ships to navigate further
• Strengthen and heighten levees
• Not always predictable and floods can often wash
  away mankind best efforts

3
River Projects

• Reservoirs and Dams - Ardnacrusha HEP,
  Blessington lakes in Wicklow, Three Gorges Dam in
  China, Aswan Dam on the Nile
• Artificial levees on Mississippi and the Rhine
• Land reclamation in Netherlands
• Irrigation schemes Central Valley USA
• Transport 50km taken of the Rhine
• Tourism Marinas on Shannon

4
River Rhine
5

• 1,300km
• Source in the Alps and mouth at Rotterdam in the
  North Sea
• Chief Tributaries Main, Neckar and Moselle
• Many main cities built along it including
  Duisberg, Cologne, Bonn, Strasbourg
• In the last 100 years vast changes made to Rhine
• Canal System created to link North Sea to
  Mediterranean and Black Sea
• River Straightened and shortened by 100km
• Dykes built to prevent flooding and islands that
  divided river were removed

6

• This resulted in a deeper, shorter, straighter,
  faster flowing river (30 faster)
• In past when in flood in spread out over large
  flood plains but now 85 of flood plains has been
  lost to agriculture and buildings, including
  worlds largest inland port at Duisberg
• Dykes and levees have been built to protect this
  land and buildings

7

• This has simply forced the river to flood farther
  downstream
• Also resulted in sediment being deposited on
  river bed which raises the river and necessitates
  the dykes being periodically raised also
• As ship sizes increased, the river was narrowed
  in places to make it deeper
• This meant the river began to flow faster so
  erosion increased
• The Rhine also flows through the polders in
  Holland which are always in danger of collapse

8

• Since 1950s HEP stations were built along upper
  section of the Rhine
• 13 stations built along the French-German Border
  in the Power-Project
• These dams trap sediments which decreased the
  rivers load and increase speed

9

• In last 100 years the Rhine has flooded on an
  annual basis
• 1995 saw biggest flood
• Heavy rain and high temp saw snow melt so several
  tributaries and Rhine broke their banks
• City of Cologne was under 2 metres of water
• In the South of the Netherlands the dykes didnt
  break but water reached the top of dykes with
  great risk of homes being under 6m of water
• Over 250,000 people and millions of animals had
  to be evacuated
• In other parts of Holland valuable horticultural,
  market gardening and dairy industry were destroyed