抄録
A selective withdrawal system (SWS) in a dam is essential for the conservation of water quality in the reservoir. However, the operation of SWS has not been fully examined in Japan so far. On the other hand, in the United States, some dams use three or more gate levels simultaneously to get desired blended water quality. In order to reveal the intake characteristics of this operation, we conducted field observations at Tono Dam. Moreover we derived quantitative intake equations using the law of conservation of momentum and energy and applied the reservoir. Field survey and the calculated results both indicated that the amount of cold water from lower intake is greater than that of warmer water from upper intake, especially in the conditions that the density stratification is developed.
