A Review of the Impacts of Dam Construction on Regional Ecosystems

With the increasing demand for water resources due to population growth and economic development, dams have become critical infrastructure for water supply, hydropower generation, and flood control. However, their construction and operation significantly alter natural river ecosystems, leading to habitat fragmentation, biodiversity loss, and other ecological challenges. This paper reviews recent research on the ecological impacts of dams, analyzing their effects through three dimensions: impact mechanisms, ecological responses, and mitigation strategies. Key findings reveal that dams disrupt hydrological processes, obstruct fish migration, and alter aquatic and terrestrial ecosystems, with regional variations in severity. For instance, the Three Gorges Dam has reduced fish spawning grounds, while dams in the U.S. have fragmented river habitats. Mitigation measures such as ecological flow releases, fish passage facilities, and watershed management can partially alleviate these impacts. The study underscores the need for balanced dam development that integrates socio-economic benefits with ecological conservation. By advancing scientific research and policy frameworks, sustainable water resource management can be achieved, minimizing irreversible damage to ecosystems.