Dams in the World and its Roles
Dams are solid barriers constructed across a river or a natural stream to create an artificial reservoir on its upstream side for storing water. It may also be constructed to facilitate diversion of water from the river or to retain debris flowing in the river
- The first known dams were constructed about 8,000 years ago in Mesopotamia
- Dams built in Jordan and Egypt – 1100BC
- Dujiang Irrigation Project in China – 300BC – 800,000 hectares
- Large Dams in the world (> 15 m high)
- In 1949 some 5,000 Existed.
- By 2000, there were 45,000.
- With the exception of the Great Wall of China, dams are the largest structures ever built
- Throughout history, big dams have prevented flooding, irrigated farmland, and generated tremendous amounts of electricity
Purpose of the Dams
- Irrigation
- Generation of Electrical Energy
- Municipal and Industrial Water Supply
- Navigation
- Flood Control
- Recreation
- Diversion
- Catching and retaining debris
Impoundment Facility
Dams in the World and its Roles
1. Tailings Dam, River Rimac, Peru, frequently contain extremely toxic materials
2. Cowlitz Falls Dam, Lewis River, Washington for Power Generation
3. Kariba Dam Zimbabwe
General Purpose
- Water Supply
- Energy Generation
- Large Area Inundated
- Change in Fish
4. Holland’s Dams Hold Back the Sea
- Flood Control
- Great Environmental Change Accepted as Positive
5. Three Gorges Dam
- Energy Generation
- Enhancing Navigation
- Flood Control
- 1,000,000 People Displaced
Some Negative Impacts of Dams
- Inundated Lands
- Displaced People
- Changes in River Regime
- Changes of Habitat
- Dam Safety Concerns
- Predicted Benefits Not Achieved
No comments:
Post a Comment