EVALUATION METHOD FOR FISHES FOCUSING ON RAPID-POOL CONDITIONS

Abstract

PHABSIM is a powerful technique to evaluate fish habitats in rivers. The suitability for fishes in PHABSIM is denoted by velocity and depth independently. Therefore, it is insufficient to represent combined influences of these factors on fish habitats. In this paper, we established a new framework of the evaluation method focusing on a hierarchical structure of fish habitats considering landscape ecology.

At first, we evaluate the fish habitat using suitability criteria on a depth-velocity plane. Then we decomposed the study site into several sub-units and estimated suitability for each sub-unit paying attention to the riverine landscape in addition to the evaluation by the depth-velocity plane. Finally we evaluated the effect of flow regime and shoreline conditions on suit ability of study areas in a conclusive part.