Abstract
This study was conducted to clarify the effects of a series of cascade run-of-river hydropower system on the stream ecosystem. To evaluate the stream ecosystem, the Odum's concepts of stream metabolism were adopted with the field survey which composed of continuous logging of water environmental variables such as dissolved oxygen concentrations and simultaneous practical sampling on attached algae and river water. The study locations were set above and below a run-of-river hydropower weirs and plants, with particular references to their reducing waters. According to the results, daily gross production, community respiration and their ratio could be evaluated at each of the conditions. It also could be clarified the cumulative effects of the hydropower generations with the degeneration of the ratios between gross productions and respirations.
