Abstract: The construction and operation of reservoir groups have changed the natural flood propagation characteristics, which are mainly reflected on the change of flood propagation time. By establishing hydrodynamical model of the reach from Zhutuo to the dam site of Three Gorges Reservoir, we simulated and analyzed the flood wave propagation characteristics under the conditions of different reservoir water levels, different surge wave flows and different maximum flow durations, hence revealing the influences of such various factors on the surge wave propagation in the reach. Results suggest that the factors affecting the propagation of surge wave in the river channel are complex. Surge wave flow, maximum flow duration and reservoir water level all exert influence on the propagation, among which the maximum flow duration has the smallest influence on the propagation time of the flood, followed by surge wave flow and reservoir water level. The research findings offer technical support for the precise forecast of incoming flood and the optimized scheduling of Three Gorges Reservoir.

Key words: surge wave, flood propagation time, reservoir area reach, flow process, water level in front of dam, three gorges reservoir area reach from Zhutuo to dam site