Effect of changes in flow runoff on the elevation of Tongguan in Sanmenxia Reservoir

摘要

This paper presents a study of the variation of the elevation of Ibngguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise of the elevation of Tongguan, which is defined as the stage corresponding to a discharge of 1000 m~3/s at Tongguan station, is controlled by the stream energy. A close relationship existed between the elevation of Tongguan and the superimposed stream energy that integrates the current and the preceding years' flow and dam operation conditions. When the flow runoff remains relatively constant and the pool level of the dam has a relatively large range of variations, then the elevation of Tongguan is primarily controlled by the dam operation conditions. On the other hand, if the flow runoff has a relatively large range of variations and the pool level of the dam remains relatively constant, then the elevation of Tongguan is primal -ily controlled by the flow conditions. These findings are of importance for optimizing the dam operation in order to lower and control the elevation of Tongguan, and therefore to minimize the backwater effect of the dam operation.