Author(s): Koji Mishima; Sohei Kobayashi; Yasuhiro Takemon; Tetsuya Sumi
Linked Author(s): Tetsuya Sumi
Keywords: Riffle and pool; Aquatic birds; Ayu fish
Abstract: The rivers in developed countries have been done the channelization, sediment control works, dam construction, and so on. These human impacts on rivers which aim river management lead to the deterioration in the river. It is necessary to assess the impact on the river condition in terms of ecological sustainability. It is necessary to estimation the river condition as a habitat. The purpose of this study is quantification of habitat, especially quantification of riffle to improve the river management method. In order to achieve the purpose, distribution of the riffle was compared with each rivers. Also, in order to confirm the validity of the relation between the riffle types and habitat density, aquatic birds aiming to catch Ayu fish riffles are counted in spawning season. In this study the difference of the longitudinal distribution of riffles in Yodo River Basin was confirmed using aerial photo, and using the result the potential habitat density was estimated. And it was assumed that as a habitat of Ayu fish traverse type riffle is chosen and pools formed in downstream of a riffle is necessary for Ayu fish to take a rest and escape from the predators like great cormorant and egrets.