The Ecohydraulic of Fish Habitats in Engineered Streams

This paper is intended to establish a mechanism by using Froude number to associate the relationship between flow conditions and fish habitats. In open channel hydraulics, Froude number, which contains two variables: water depth and water velocity, is extensively applied to describe flow type. Utilizing single hydraulic variable such as Froude number to define flow type simplifies two variables, water depth and water velocity, in describing the differences of flow types. The study site is in the Dago Stream, Taipei City, Taiwan, with aim to find the confident intervals of fish habitat occurrence proportion and Froude number distribution during regular flow. After fieldwork in the Dago stream, there are nine aboriginal fishes, however the Scaphesthes barbatulus and Gambusia affinis are excluded from this statistic due to the little amount. The Hemibarbus labeo habitat was most likely to occur at lower Froude number class ranging from 0.3 to 0.4. But the Monopterus albus habitat was most likely to occur at higher Froude number class ranging from 0.4 to 0.8. Zacco pachycephalus, Acrossocheilus paradoxus, Rhinogobius brunneus and Candidia barbata were extensively existed in the range of Froude number between 0.3 to 1, but the optimum habitats of Rhinogobius brunneus and Candidia barbata appear from 0.8 to 1.1. This information can be applied to torrent control, depending on changes of channel morphology to create an Environment of habitat heterogeneity and biodiversity.

並列關鍵字

Ecohydraulic ； Froude number ； Fish habitat ； Ordinary flow

國際替代計量

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