Analysis of impacts of dams on ecological environment for river ecosystem

The dam and environment is a very important topic of the harmonious relation between human and nature. The problem of impact of the dam on the ecological environment has achieved more and more attention in recent years. Here the factors of ecological environment impacts of the dam on river ecosystem are divided into two aspects, id biotic factors and abiotic factors, and three orders are adopted according to their influence extent. Then the impacts of building dam on the first and second order abiotic factors, and on the second and third order biotic factors are analyzed. Finally, the research for the problem of ecological environment impacts of the dam is expected, and it is proposed that the study of the ecological environment impacts of the dam should be put attention on the entire rivers ecosystem. In the meantime, the accumulation effect of rundle dams should be considered.