Author(s): Kazuhiro Azami
Linked Author(s):
Keywords: No Keywords
Abstract: Due to high population densities and sudden changes in flow discharge in the Asian Monsoon climate, there is a demand (or requirement) for building dams for irrigation and flood control in Asia. The country with the most dams is China, with 22,000 dams, followed by the United States with 6,575 dams, India with 4,291, Japan with 2,675, and Spain with 1,196 dams (WCD [1], Okano [2]. Asia is one of the continents with the most dams worldwide. Although circumstances may differ in different areas of the world, the fact that dams hold back the natural river current and create large regions of permanent water is incontrovertible. Biological communities respond to physical changes in the environment. The flow regime plays a significant role in the riverine ecosystems as it affects seasonal changes in the flow volume and floods of small, medium, and large scales, contributing to the maintenance of animal habitats and natural purification, while the life cycles of plants and animals in the river are adapted to the flow regime. For example, small- to medium-scale floods remove and transport the detritus accumulated on the riverbed and water’s edges, activating the adhesive algae and improving their quality as the food resource for fishes and benthic animals. Dams interrupt the natural flow of rivers, changing running water to still water, and thus are considered to exert strong influences over the nearby river morphology and ecosystems.
Year: 2018