Grand Dixence Scheme, Switzerland - examole of human change creating change.

What is the Grand Dixcene?

It is a hydroelectric powerdam

When was the Grand Dixcene built?

1960

Where is the Grand Dixcene?

The head of Val des dix (glacial valley) in switzerland

How much did it cost to construct:?

1600 million francs

How is the dam supplied with water?

seasonal meltwater of 35 glaciers.

How many households does the dam provide for?

400,000

What makes the dam an efficient system?

It stores meltwater from the summer, and uses it to supply energy during te winter when the demand is greater

What was done during the construction of the dam to minimise visual impact?

Power and pumping stations built underground.

What impacts has the dam had on the Borgne river?

It has reduced flow downstream - causing higher concentrations of pollutants (originating from homes + agriculture)

Due to water being stored in the resevoir, what issue has been caused for the flow of water?

Sedimentation - when a loss of energy in the river causes excess deposition

How much sediment is added to the river every year?

20 to 40cm

How many power stations in the GD

4

what proportion of swiss energy comes from storage power stations?

1/3

How much water does the Grand D dam hold?

400 million m³

How much of the energy made at Grand Dixence is used for the problems of sedimentation?

15%

Why is there excessive erosion around the dam?

sediment becomes trapped above the dam, and so the middle course of the river travels super fast and so excess energy erodes the sides.

How has tourism been hindered by the dam?

Flooding risks downstream as water is released from the resevoir - stopping services such as toursism as visitors can’t arrive to their destination.

What happend in 2000

A pipeline burst causing a landslide that killed three people and destroyed a hamlet.

What are the effects of the changes from the dam on glacial landforms?

As all the water is held up behind the dam, downstream rivers often dry up in the summer, river channels have shrunk and more contraction has occured

How have the changes in teh landscape affecte irrigation?

They have reduced sediments - meaning that channel lining is required as sediments payed a crucial role in stopping infliltration

What makes the dam a complete waste of money

climate change will mean the glacier will melt entirely, meaing there was no purpose for it and it will lie derelict and leave a scar on the landscape.