基于水文水动力耦合模拟的三峡水库调度对下泄流量影响研究

Study on the influence of the Three Gorges Reservoir operation on water discharge based on hydrology and hydrodynamic coupling simulation

基于分布式水文模型与三峡库区水动力模型的耦合,模拟了2012—2018年三峡水库在实际调度、规程调度、无库调度3种模式下的下泄流量,分析三峡水库在规程调度和无库调度模式下的下泄流量在不同水文关键期的影响作用。研究结果表明,耦合模型符合模拟精度要求,可有效模拟三峡水库下泄流量。除汛期外,三峡水库规程调度的贡献在供水期最为敏感,且主要与天然径流的变化相关,供水期平均天然径流每升高1000 m^(3)/s,规程调度的贡献下降约15%;规程调度在蓄水期的贡献与天然径流及规程调度下泄流量共同相关,蓄水期平均天然径流每升高1000 m^(3)/s,规程调度的贡献下降约0.79%。汛期洪峰来临前,规程调度可通过提前7日下泄洪量的方式对洪峰来临前3、5日的累计拦截洪量产生直接影响,从而起到一定的削峰作用。

Based on the coupling of the distributed hydrological model and the hydrodynamic model of the Three Gorges Reservoir(TGR)area,this paper simulated the water discharge of the TGR during 2012—2018 under the actual scheduling,regulated scheduling and natural state,and analyzed the influence of the different scenarios on the water discharge characteristic of the TGR in different hydrological key periods.The results show that the coupled model can satisfy the requirement of simulation accuracy and can effectively simulate the water discharge of the reservior.Except flood season,the contribution of TGR regulated scheduling is most sensitive in water supply season,and it is mainly affected by natural runoff.In water supply period,the contribution of regulated scheduling is mainly related to the change of natural runoff.When the average natural runoff increases by 1000 m^(3)/s in the water supply period,the effect of regulation decreases by 15%.The contribution of regulated scheduling in the impounding period is correlated with natural runoff and regulated water discharge.When the average natural runoff increases by 1000 m^(3)/s during the impounding period,the effect of regulated scheduling in the impounding period decreases by 0.79%.Before the peak flow arrives,the regulated scheduling of the TGR can change the interception flood volume of 3 and 5 days before the flood peak by releasing the water 7 days ahead,thus playing a certain role in peak cutting.