Question

What are the short-term and long-term effects on the environment that can arise from the construction of dams?

Answer 1

Dams and reservoirs are constructed in order to prevent floods, to supply drinking and domestic water, to generate energy and for irrigation purposes. One of the most efficient way to manage water resources for human needs is by the construction of dams that creates reservoirs for storage and future distribution. Currently there are around 45000 dams higher than 15m height throughout the world

Dam construction has both short term as well as long term effects on environment some of the short term effects are as follows.

1)Resettlement and relocation : The construction of large dam has resulted in the displacement or Resettlement of many million people's homes, the loss of many valuable archeological and cultural sites, as well as significant ecological change. It is estimated that to date 40-80 million people worldwide have been physically displaced from their homes as a result of dam construction.

2)Disappearance of historical places :archeological and historical places in company with geological and topographical places that are rare with their exceptional beauties disappear after lying under reservoir.

3)Loss of economy :Although dams have a lot of positive impact but when it is constructed it tells upon the budget of concerned region as making of massive structure burns a hole in the pocket

The long term effects are as follows :

1)Aquatic life :The dam is a real obstacle for the animals swimming from one end of river to the other end. The existence of dam means death for fish species spending certain part of their life in the spring or in flood gates, turbine. A dam that will be built on the way will interrupt the life cycle of these creatures and cause death in a mass.

2) Scouring of Rivers:water releases from reservoirs including that existing a turbine usually contains a very little suspended sediment, and this in turn can lead to scouring of river beds and loss of river banks.

3)Human health:Wood and garbage accumulated because of dam may cause increase in water sourced illness like typhoid, fever, malaria, cholera which affect the human health living around the dam and reservoirs