Study of the Environmental Impact of Constructing Dams on the Environment

Undoubtedly, water is considered as one of the pivotal and fundamental bases for the development of communities in different countries. The development of water resources by constructing big and small dams in accordance with their situation and circumstances has been caused enormous environmental changes. Mutual impacts of dams on the environment can be assessed at two aspects of positive and negative effects. The dam as a barrier on the river creates different physical and chemical features in the place, shoal and mirage of the dam. despite various advantages which this function has had on the limitation of exploitation, such as decreasing the abundance and intensity of floodwaters and the accessibility to water in arid or drought years, but constructing such structures can strike the balance of natural systems and it would leave many short term and long term environmental impacts on that region or other regions which are affected by constructing dams. These impacts may have some influence on the condition and behavior of aerology, biology and hygienic, culture, monuments etc. and seriously will cause to change it. As a result, regarding the importance of positive effects of constructing dams, in order to stable development their negative environmental impacts should be minimized. In the present paper, the environmental impact of constructing dams on the environment has been assessed from different aspects.