Concrete and embankment dams are much better suited to carry horizontal loads than buildings and bridges. Large dams are required to be able to withstand an earthquake with a return period of about 10,000 years, whereas buildings and bridges are usually designed for an earthquake with a return period of 475 years.

Some water supply structures are susceptible to earthquake motion. Embankments and outlet towers respond to earthquake vibrations. The effects of a dam failure on people and structures downstream are dramatic and obvious. A more likely example of earthquake damage would be loss of control of the water supply.

High arch dam can serve as a large volume concrete structure. The dam body foundation reservoir water dynamic interaction under the seismic action affecting seismic response has been very important.

A dam is a structure built across a river or stream to hold back water. People have used different materials to build dams over the centuries. Ancient dam builders used natural materials such as rocks or clay. Reservoirs can be used to store water for farming, industry, and household use.

Dams change the way rivers function. They can trap sediment, burying rock riverbeds where fish spawn. Gravel, logs, and other important food and habitat features can also become trapped behind dams. This negatively affects the creation and maintenance of more complex habitat (e.g., riffles, pools) downstream.

In this week’s blog, we take a look at the seven most strange and beautiful dams around the world.

• 7) Hoover Dam – Nevada/Arizona, United States.
• 6) Three Gorges Dam – Hubei, China.
• 5) The Karun-3 Dam – Khuzestan, Iran.
• 4) The Inguri Dam – Jvari, Georgia.
• 3) Vajont – Erto E Casso, Italy.
• 2) Sand Dams – Kenya.

Parker Dam

List of largest dams

Bratsk Dam in Siberia, Russia, ranks as the second biggest dam in the world thanks to its 169.27 billion cubic metres reservoir.

Hirakud dam

China

The first constructed dams were gravity dams, which are straight dam made of masonry (stone brick) or concrete that resists the water load by means of weight. .” Around 2950-2750 B.C, the ancient Egyptians built the first known dam to exist.

Tehri Dam

4 Species Impacted by Dams

• Sturgeon. Dams divide rivers, creating upstream and downstream habitats.
• Egrets. Egrets, along with other wetland birds, depend on healthy river systems for food and shelter.
• Irrawaddy Dolphins. All river dolphins need freshwater fish, quality water and safe migratory routes to survive.
• People.

Dams harm fish ecology via river fragmentation, species migration prevention, reservoir and downstream deoxygenation, seasonal flow disruption, and blockage of nurturing sediments. Drastic sudden fish losses due to dams can also destroy the commercial and subsistence livelihoods of indigenous and traditional peoples.

Dams have a great deal of positive and negative effects on the environment be- sides their benefits like controlling stream regimes, consequently preventing floods, obtaining domestic and irrigation water from the stored water and generating en- ergy.

Washington

Three Gorges Dam

States that produce large amounts of hydro energy in the country are Washington, California, New York, Oregon, and Alabama. In 2018, the US hydroelectricity generation capacity was 80 million kilowatts.

Hydropower fell out of favor in the ’90s because of the harm it can cause to communities and ecosystems. However, a recent push from the World Bank for more hydro projects worldwide, especially in developing countries, could lead to a resurgence of hydropower plants, the Washington Post reports.

Renewable energy capacity 2020, by country The leading countries for installed renewable energy in 2020 were China, the U.S., and Brazil. China was leading in renewable energy installations with a capacity of around 895 gigawatts. The U.S., in second place, had a capacity of around 292 gigawatts.

Pros of Hydroelectric Energy

• It’s Good for the Environment.
• It’s a Renewable Resource.
• It’s Reliable and Highly Efficient.
• It’s Flexible.
• It’s Safe.
• It’s Economical.
• It’s Great for Recreational Use.
• It’s a Fundamental Vehicle for Development.

Hydropower generates about 24 percent of the world’s and 12 percent of the United States’ electricity.

With 1 MW enough to power 750-1,000 average American homes according to Electric Power Supply Association, that’s enough generating capacity to produce electricity for roughly 75 to 101 million homes.

A micro hydropower plant has a capacity of up to 100 kilowatts. A small or micro-hydroelectric power system can produce enough electricity for a home, farm, ranch, or village.

Advantages of hydroelectric energy

• Renewable. Hydroelectric energy is classified as a renewable energy source because it is powered by water, and water is a naturally replenishing resource.
• Low emissions.
• Reliable.
• Safe.
• Environmental consequences.
• Expensive to build.
• Drought potential.
• Limited reservoirs.

Converting over 90% of available energy into electricity, hydropower is the most efficient source of electrical energy. By comparison, the best fossil fuel power plants operate at approximately 60% efficiency.

Hydropower is the most important and widely-used renewable source of energy. Hydropower represents about 17% (International Energy Agency) of total electricity production. China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States (Source: Energy Information Administration).