The Nile Delta Flashcards Preview

A Level OCR Geography Paper 1 Case Studies > The Nile Delta > Flashcards

Flashcards in The Nile Delta Deck (20)
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1
Q

Give some background?

A

It is a low energy coastal environment.
Rates of fluvial deposition have exceeded marine erosion for over 3000 years.
The situation is changing due to the influence of human and physical factors.

2
Q

How long is the River Nile?

A

6650km

3
Q

What is the River Niles catchment area?

A

3million km^3

4
Q

What is the mean rain fall in the catchment?

A

600mm average a year

5
Q

What is the average discharge?

A

3000m^3 per second, one of the lowest of the great rivers.

6
Q

What is the annual sediment yield?

A
  1. 26t/ha/year

91. 3 million for whole Blue Nile basin

7
Q

What is the distribution of the Niles sediment load?

A

30% clay
40% silt
30% fine sand

8
Q

What is the coastal plain?

A

The Northern part of the Nile Delta, runs parallel to the Mediterranean coastline.

9
Q

What are the 3 Subunits of the coastline?

A

Foreshore plain
Frontal plain
Sandy zone

10
Q

What is the Foreshore Plain?

A

Characterised by elongated ridges.
Runs parallel to the present shoreline.
Alternates with lagoons, salt marshes and alluvial deposits between them.

11
Q

What is the Frontal Plain?

A

Located south of the foreshore plain.

scattered eroded limestone outcrops and clay deposits.

12
Q

What is the Sandy Zone?

A

Comprised of different sand formations such as sheets, dunes and hummocks.

13
Q

How do the distributries split?

A

Splits at Cairo 160km inland into distributries which fan out over the whole delta.

14
Q

What happened before the Aswan High Dam?

A

Before the construction in 1964 the Niles annual flood would cover t much of the delta in a thick layer of silty mud.

15
Q

How do barrier bars form?

A

Wave action in the Med redistributes the sediment in front of the delta, the reworked sediment forms a series of curved barrier bars.

16
Q

What is the effect of barrier bars?

A

They close of segments of the delta to the Mew, forming lagoon which then fill with fine sediment.

17
Q

What is the wind like?

A

Prevailing Northwesterly wind, enhances the constant eastward movement of water and sediment.
Estimated surface velocity of 10cm/s in summer.
4.5cm/s in Autumn
23cm/s in Winter
Wind leads to waves from the Northwest 60% of the time and NE 8%.

18
Q

What is the main landform?

A

Different types of sand bars.

19
Q

What are the different types of bars?

A

West of Abu Qir has long cresentic bar systems associated with rip currents and negligible LSD.
East of Abu Qir has long parallel bars generated by dominant eastward longshore current and associated LSD.

20
Q

What are the effects of the Aswan High Dam?

A

An imbalance between erosion and accretion
Rapid reduction in the ammount of sediment accreted, from 120 million tonnes to trace amounts.
NW shoreline has accelerated erosion rates at 148m/year.
Rising Med sea levels of 1.2mm/year have contributed to higher erosion rates.
Deeper water causes larger waves to reach further inland.