GEOTHERMAL ENERGY IN ROMANIA

Environmental Impacts of HydroPower

About hydropower The water behind the dam flows through an intake and pushes against blades in a turbine, causing them to turn. The turbine spins a generator to produce electricity. The amount of electricity that can be generated depends on how far the water drops and how much water moves through the system. The electricity can be transported over long-distance electric lines to homes, factories, and businesses.

Hydropower (from hydro, meaning water) is energy that comes from the force of moving water. The fall and movement of water is part of a continuous natural cycle called the water cycle. A typical hydro plant is a system with three parts: an electric plant where the electricity is produced; a dam that can be opened or closed to control water flow; and a reservoir where water can be stored.

About hydropower Clean and renewable energy source Hydropower is the cheapest way to generate electricity today. That's because once a dam has been built and the equipment installed, the energy sourceflowing wateris free. It's a clean fuel source that is renewable yearly by snow and rainfall.Furthermore, hydro plants do not emit pollutants into the air because they burn no fuel.Hydropower is also readily available; engineers can control the flow of water through the turbines to produce electricity on demand. In addition, reservoirs may offer recreational opportunities, such as swimming and boating.Hydropower plants produce power cheaply due to their sturdy structures and simple equipment. Hydro plants are dependable and long-lived, and their maintenance costs are low compared to coal or nuclear plants.

Summary of the Environmental Impacts of Dams Damming rivers may permanently alter river systems and wildlife habitats.

The impact of dams on river ecosystemsNegative effectsNegative environmental effects due to construction activitiesLoss of wild lands, wetlands and wildlife habitatEffects of stopping the flow of nutrients downstreamReduced biological activity downstreamAnaerobic decomposition of vegetation and production of greenhouse gassesWater-loss due to evaporationChanges in water quality due to the lack of dissolved oxygen near the bottom of reservoirs. This is toxic to fish and can lead to the death of aquatic life. It is also corrosive to turbines.

The impact of dams on river ecosystemsNegative effects

Accomodation of amphibians, riparian fauna and birds to a new environmentMigration of animals to new areas, where new equilibrium may favour some species over othersBlocking fish migrationIntroducing of new species of fish in the reservoirsInappropriate reservoir operation with large variations in water levels could threaten fish by drying up shallow-breeding and flood producing areas.

The impact of dams on river ecosystemsTHE PYRAMID OF IMPACTS

www.labond.com/Dams/...The Iron Gates Dams and disruption of spawning migration of Danube sturgeonsSturgeons are very sensitive to habitat changes. Altered habitats can immediately impact on their spawning, wintering and feeding success, and ultimately lead to their extinction.Iron Gates is the largest hydropower dam and reservoir system along the entire Danube. The system consists of two main dams, Iron Gates I and II, built in 1972 and 1985 respectively. The dams are constructed at river km 942 and river km 863 upstream of the Danube delta, in effect confining migratory sturgeons to 863 km of the river and cutting off important spawning sites in the Middle Danube.The Iron Gates dams do not have technical equipment such as fish passes or bypasses, designed to assist fish migration.Danube sturgeons species

Danube sturgeons species

Danube sturgeons species

Danube sturgeons species

Danube sturgeons species

REFERENCESFlorin BalaciLaurentiu Buse

http://www.need.org/needpdf/infobook_activities/SecInfo/HydroS.pdfhttp://www.alternative-energy-news.info/technology/hydro/http://environment.nationalgeographic.com/environment/global-warming/hydropower-profile/http://danube-sturgeons.org/

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