case study for dams- nile delta

Question 1

how much sediment is trapped before it reaches nile delta

Answer 1

-98%

Question 2

how many dams on river nile

Answer 2

29 dams securing an electricity supply to poorer regions

Question 3

what is the delta

Answer 3

-depositional landform formed from sediment brought down the Nile by annual floods

Question 4

example of dam bit on the nile

Answer 4

-Aswan high dam in the 1960’s

Question 5

how much did the Aswan high dam block the river discharge by

Answer 5

-fell from about 35 billion metres cubed per year
-to about 10 billion metres cubed per year

Question 6

how much did the Aswan high dam cause the sediment volume to fall by

Answer 6

-from 130 million tones to 15 million tonnes

Question 7

what are the changes in the sediment volume of the Nile caused by

Answer 7

(1) water withdrawals for industry, farming from reservoir behind Aswan high dam
(2) Sediment being trapped by reservoir and dam as the water flows really slowly allowing sediment deposition

Question 8

what is the effect of the blocking of sediment supply in the nile

Answer 8

-Erosion rates at the Rosetta (where main delta branch of river meets sea) jumped from 20-35m to over 200m per year
-due to sediment starvation

Question 9

how is the Akosombo dam case study different from Nile

Answer 9

-more rapid coastal recession and flooding than nile
-for example at Tongo and benin coastal recession is 15-20m/year

Question 10

how much is the sediment down the Volta in Ghana stopped by the Akosombo dam

Answer 10

-from around 70 million metres cubed a year to less than 7

Question 11

what does the Akosombo dam impact in Ghana and neighbouring countries

Answer 11

-major impacts on longshore drift and coastal erosion