The identification of the water level time lag (WLTL) under the regulation processes is of great significance for environmental impact, flood control, and sediment transport of huge reservoirs. The traditional hydrodynamic method can calculate the flood inflow process and the water level change process along the river channel, but it is difficult to estimate the time difference of the reservoir water level fluctuation to the dispatching process. To quantitatively evaluate the reservoir regulation effect on the WLTL in the Three Gorges Reservoir (TGR), the daily water level data from 2011 to 2017 of five stations in the TGR are analyzed in this paper. The results revealed that there is a significant water level difference along the reservoir from April 1 to October 31. The gap between the end of the reservoir and the Three Gorges Dam (TGD) is the largest, reaching 23.67 m on July 2. The longer the distance from the TGD, the longer the time lag. Furthermore, the WLTL is also different at the four different operating periods of the reservoir in a year. During the low water level operation period and high water level operation period, the time lag is 3 days which is the greatest, while in the water level decline period and water level rise period, the time lag is within 2 days.

调控过程中水位时滞（WLTL）的识别对于大型水库的环境影响、防洪和输沙具有重要意义。传统的水动力方法可以计算沿河道的洪水流入过程和水位变化过程，但难以估计库水位波动对调度过程的时间差。为定量评价三峡水库(TGR)水库调控对WLTL的影响，本文对三峡水库5个站点2011-2017年的日水位数据进行了分析。结果表明，4月1日至10月31日，水库沿线水位差异显着。水库末端与三峡大坝（TGD）之间的差距最大，7月2日达到23.67 m。距离三峡大坝越远，时滞越长。此外，水库一年内四个不同运行期的WLTL也不同。在低水位运行期和高水位运行期，时滞最大为3天，而在水位下降期和水位上升期，时滞在2天以内。