1. Delta

2. Where can you find delta?
Mouth of river

3. What is a delta?
A flat depositional plain formed at the river mouth

4. Types of delta

5. Arcuate delta
Triangular in shape
E.g. river Nile, Egypt, Africa.

6. Map of Nile

7. The Nile Delta
Satellite Image

8. Bird’s foot delta Look like a bird’s foot
E.g. river Mississippi, U.S.A, North America.

10. Mississippi Delta
Satellite image

11. Estuarine delta No particular shape
E.g. river Amazon, Brazil, South America.
Estaurine delta

12. The Amazon River

13. Satellite image of Amazon river mouth

14. A B
Examples from China C

15. Huang He Satellite image
Arcuate delta

16. B
Chang Jiang delta p. 48
Shanghai
Satellite image
Estaurine delta

17. C. Zhu Jiang Delta
Estaurine delta
Satellite image

18. Discussion
What are the uses of delta to man? Explain your answer. Quote examples.
What are the favourable conditions for the formation of delta? (Think in terms of the river characteristics and the coastal environment……)

19. The uses of delta …..

20. And many more ….

21. Conditions favouring the formation of delta
Characteristics of the river
River carries a large load
There are few or no lakes along the river

22. Characteristics of the coastal environment
Sheltered bay
Weak tides and waves
Removal of sediment is slower than deposition
Gentle offshore slope
Shallow sea
Presence of vegetation

23. Formation of delta When a river bring down a large amount of sediment
River reaches the sea, it slows down
Particles group into larger and heavier particles (flocculation process)
When sediment is deposited faster than it can be removed, delta is formed

24. Exercises
Complete the worksheet
Homework – Nam Chung River, p.55-56