Environmental Effects of Dams (by braedenkey)

Environmental effects of Dams

Harm of Dams

~The construction of large dams has changed the relationship betweem water and land. ~It's destroying the ecosystem balance which has taken thousands of years to create. ~Right now there is approximately 40,000 large dams that alter the world's rivers, changing their circulation systems.

Dams:Dams are massive barriers built across rivers and streams to confine and utilize the flow of water for human purposes such as irrigation and generation of hydroelectricity. This confinement of water creates lakes or reservoirs.

Fun FactThe first known dam was built in 2900 B.C. across the Nile River to protect the city of Memphis from flooding.

Watch the effects of Dams

Effects on the Environment

Dams have many negative effects on the environment such as:Soil Erosion- Dams hold back the sediment load normally found in a river flow, this lowers the riverbed threatens vegetation and river wildlife.Spread of Disease- The low water grounds are breading grounds for mosquitoes, snails, and flies, the vectors that carry malaria and other bad thingsFish Migration- Many damns are built without fish ladders with make is hard for fish to get downstream, this will leave them as easy bait for preditors

Positives of Dams!

With the many negastives dams bring. there are also a few positives dams provide. They assist in controlling floods in many areas, are used to create clean energy with hydroelectric power and the lakes created are often used as recreation sites by humans and animals alike.

http://www.ussdams.org/howdam.html

http://news.nationalgeographic.com/news/2011/03/photogalleries/110331-mekong-river-dam-endangered-megafish/

By: Braeden Key