River Thames

1. River Thames Terence Lam

2. Information of River Thames • Location : southern England • Length : 346km (second longest in the United Kingdom) • Source :Thames Head • Mouth :Thames Estuary, North Sea • Cities flow through : London , Windsor , Oxford • Average discharge :65.8 m /s 3

3. Importance of River Thames • provide habitation, water power, food and water • International trade & cultural canter -acted as a major highway

4. Thames Barrier

5. Information about Thames Barrier • World's second-largest movable flood barrier • Built across a 520-metre wide stretch of the river • Total construction cost: around £534 million • Location: downstream of central London

6. Reasons for building Thames Barrier • Prevent London from flooding - A storm surge generated by low pressure in the Atlantic Ocean sometimes tracks eastwards past the north of Scotland -may then be driven into the shallow waters of the North Sea. • Rising of water levels • Historical flooding - 1928 Thames flood

7. Thames Barrier in action

8. Design of Thames Barrier • rotating gates • divides the river into four 61 meter and two about 30 meter navigable spans • gates are hollow • made of steel (40 millimeters thick) • 20.1 meters high & weigh 3,700 tones (4 central gates)

9. Source: Wikipedia BBC

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