美国还有9.1万个水坝，中国有9.8万个, 欧洲国家有1.2million 水利设施。 非洲据说有1000个左右大坝

There are over 91,000 dams in the US, with some estimates reaching over 500,000, many of which provide benefits like flood control, water supply, and hydroelectric power. Despite the large number of dams, many are aging, deteriorating, and no longer serve their original purpose, leading to safety hazards and environmental concerns that prompt ongoing efforts to repair or remove them. 

 

Why we still need dams

• Flood control: Dams help prevent flooding by holding back excess water and releasing it in a controlled manner.
• Water supply: They act as reservoirs, storing water for drinking, agriculture, and industrial use.
• Hydropower: Many dams generate electricity through turbines, providing a source of renewable energy.
• Irrigation: Dams supply water for agricultural irrigation, which is crucial in many parts of the country.
• Navigation: They create or maintain navigable waterways for commercial and recreational boats.
• Recreation: The reservoirs created by dams are often used for recreational activities like boating and fishing. 

 

China has over 98,000 dams, and they are still needed for hydropower, flood control, and water security, though climate change and dam management present new challenges. These dams are crucial for generating electricity, providing water for agriculture and industry, and preventing catastrophic floods, which have historically caused immense damage along major rivers. However, the construction of numerous dams, particularly the mega-dams, has had negative environmental impacts. 

 

 

 

here are likely between 600 and 800 large dams in Africa, though a precise number is difficult to confirm. Dams are still needed for crucial functions like irrigation, providing clean drinking water, and generating hydropower, which is a key source of renewable energy for many countries. However, building dams is often controversial due to negative impacts like development-induced poverty, social displacement, and inequitable distribution of benefits. 

 

How many dams are in Africa?

• The exact number is not definitively known, but estimates for large dams and reservoirs range from 600 to 800.
• One source states there are over 1,270 large dams in Africa, but this number may be less up-to-date or use a different definition.