Abstract:

Based on the measured data of water level and discharge in 2018 and one-dimensional analytical model, this paper focuses on the propagation process of flood wave in the river between two dams driven by hydropeaking regulation. During daily hydropeaking regulation of Three Gorges dam and Gezhouba dam, the outflow flow of both two dams shows significant daily and semi-daily fluctuation, the average daily fluctuation range of the two power stations is about 1500-2000 m³/s and 1200-1500 m³/s, respectively. The daily fluctuation of water level in Huanglingmiao and Nanjinguan stations is about 0.5-0.8m. Based on one-dimensional analytical model, the fluctuation process of water level and discharge between two dams can be simulated and reproduced well. The simulation results show that the flood waves in the river between two dams are propagated by high frequency standing waves with a period of 1.2h, and the maximum water level and flow amplitude of standing waves are about 2.1 cm and 210 m³/s, respectively. The flood wave is superimposed by the hydropeaking regulation of both two dams. Hence the regulation time of the downstream Gezhouba dams has a significant influence on the flood wave propagation. If the regulation time is adjusted from the 0.6h to 1.2h, the flood wave amplitude will be significantly enhanced. The bottom friction has little effect on the wave height, but it will expedite the attenuation time of the flood wave during its propagation.

Key words: hydropeaking regulation, flood wave, analytical model, standing wave, energy attenuation