ABSTRACT
The sediment delivery rate is one of the indicators of a reservoir’s sediment interception degree. The greater the sediment delivery rate, the smaller the intensity of a reservoir’s sedimentation. Conversely, the smaller the sediment delivery rate, the larger the intensity of a reservoir’s sedimentation. In this study, based on the measured data of each hydrologic station in the Three Gorges Reservoir area from 2004 to 2012, the sediment delivery rates of the Three Gorges Reservoir’s influence factors were analyzed. It was considered that the dam front water level, along with the reservoir’s inflow(outflow), were the main factors affecting the sediment delivery rate of the reservoir, followed by the sediment inflow, and particle size. Moreover, it was concluded through further analysis that the sensitivity of the sediment delivery rate to water level changes rapidly increased with the increase of the reservoir’s inflow. When the reservoir’s inflow was less than 15,000 m3/s, the reservoir’s water level changes had little impact on the sediment delivery rate. However, when the reservoir’s inflow was greater than 20,000 m3/s, the sediment delivery rate of the reservoir changed greatly, and the reservoir’s water level increased from 138 m to 155 m, while the sediment delivery rate was reduced from 62%, to less than 10%. Therefore, in order to improve the sediment delivery rate of the reservoir, an operational mode of “low level for abundant water, high level for scarce water” was recommended for the reservoir’s future scheduling. The research results of this study provide references for further study of the sediment delivery rate of the Three Gorges Reservoir, as well as its operation.
