Coasts - Nile Delta CS - LE Flashcards
What is the Nile Delta made from?
Made from silt (alluvium) deposited as the river which loses energy meets the sea.
What is the delta?
- Has a dendritic like pattern
- Arcuate
- Flat low lying land
What sea defences have been built on the Nile Delta?
- Sea walls
- Fisheries
- Changing land use
How do people use the silt on the delta?
They use it to make mud bricks on the building
Why did 30,000 fishermen lose their jobs?
- Less nutrients in the sea
- Sardine fisheries declined from 18,000 to nothing
How far has sea level risen to and what has that resulted in?
- 1.2 mm/yr
- Strong waves
- Increased erosion
How are lagoons being poisoned?
Chemical fertilisers -> due to less sediment because of dam
What does the main river channel split into?
Distributaries
At what rate does the delta erode per year?
30m/yr
Whats the closest city?
Cairo
Describe the forshore?
- Elongated ridges running parallel to the present coastline
- Salt marshes
- Lagoons
- Crescentic bar
- Two lobes - promontories
What it the length of the Nile?
6650km
Where is the fluvial sediment sourced from?
Ethiopian Traps
What is the average discharge of the Nile?
3000 m^3/s
What is the sediment load of the Nile?
- 30 % clay
- 40 % silt
- 30 % sand
What is the direction of sediment movement?
Eastward
Where does the prevailing wind come from?
The north west
Why are crescentic bars found at Alexandria?
Rip currents + LSD
Why has the sediment budget been affected?
Aswan Dam reducing amount of fluvial sediment
How has the sediment budget been affected by the Aswan Dam?
- Rapid reduction in sediment accretion
- Changes in erosion
Whats the rate of coastal retreat?
148 m/yr
Why is Alexandria important?
- Major economic centre
- Vulnerable to rising sea levels
- Popular tourist destination
- Natural gas + oil pipelines from Suez
What are the human causes and impacts?
- Rise of fish farms
- Increased salt production
- Heightened agriculture production -> use of freshwater
- Building dams
How much of Egypt’s population live in the delta?
2/3
Why has the store of water been reduced?
Agriculture
- Water extraction
- Irrigation
What has reduced water store led to?
The shrinkage of the delta
What are the main human activities taking place on the delta?
- Hydroelectric Power (Aswan Dam)
- Damiette Port
- Fish farms
- Oil extraction along tributary
- Cotton farms
What are the physical factors which contribute to the low energy environment?
- Small fetch
- Low wind speeds
- Shallow bathematry
- Microtidal
What land forms or features of the delta are interconnected?
- Lobes and onshore bars
- Distributaries and the lobes
- Onshore bars and lagoons
What are the mitigation strategies against the shrinking of the delta due to sea level rise and increased erosion?
- Crops with high tolerance to salinity
- Develop coastal protection policies
- Changing land use
- Develop early warning systems against floods
