Geometrical Characteristics of Pools and Habitat of Fishes in Sendai River

Abstract

Of elements related to river environment, pools play an important role in habitats of fishes. We investigated the geometrical and hydraulical features of a few pools naturally formed in Sendai River and observed the situation of habitat of fishes. The results indicated that the pool in the channel bend gave the inhabitable place to fishes due to the non-uniform structure of flow and river bed topography. The formation process of pool was also investigated theoretically and observationally with a focus on step-pool formation in mountain rivers. The comparison between theoretical and observational results showed that the pools were formed by the flood occuring once five years and the interval of the pool can be calculated by the presented method.