乌江上游电站联合运行对东风库区水文情势影响分析

Influence of joint scheduling of Wu River's upstream reservoirs on hydrological regime of downstream Dongfeng Reservoir

乌江上游电站群的开发建设对区域水资源时空分布的具有较强的调节功能,这种功能会对下游水库的库区水文情势及发电防洪能力产生直接影响。本文采用基于实测数据的模拟反演方法对该影响程度进行分析:以乌江流域洪家渡、引子渡、东风三个大型电站组合作为研究对象,运用率定验证合理的MIKE11水环境数学模型,以典型平水年实测水文数据作为水文计算条件对上游洪家渡、引子渡电站建设前后的水文变化过程进行反演模拟,并结合实测水文数据对东风水库水文情势影响程度进行了定量评估,分析结果表明:(1)上游引子渡单库运行后使得东风水库平水年入库径流汛枯比由天然情况的5.76降至4.22;洪家渡与引子渡联合调度运行后,东风水库入库径流汛枯比进一步降至1.96。(2)上游引子渡单库运行后使得东风库区洪期防洪库容增大14.2%;洪家渡引子渡联合运行后东风洪期可用库容增大38.7%,防洪能力得到在一定程度上得到进一步提升。评估数据表明乌江上游水库联合调度对东风水库水文情势影响具有较为明显的累积性,通过电站的联合调度可更好的帮助下游电站发挥防洪发电效益。

With continuous development of hydropower on the Wu River, the regulating functions of its upstream reservoirs show great impacts on the hydrological environment and flood defense of a downstream reservoir. This paper develops mathematical models for this river and demonstrates their applications to simulation of the hydrodynamics that are influenced by the scheduling conditions of upstream reservoirs, focusing on influences of joint scheduling on the runoff and storage capacity of the Dongfeng reservoir. The results show that： 1） the inflow of Dongfeng is affected by the operation of upstream reservoirs and its seasonal variations are reduced, with the annual mean high-low inflow ratio decreasing from 5.75 to 4.22 when the upstream Yinzidu operates and further up to 1.96 when both Yinzidu and Hongjiadu are jointly operated and scheduled. 2） The pressure of flood control on Dongfeng can be relieved by running the upstream reservoirs. Its capacity increases by 14.4% and 38.7% in the above two cases respectively. Furthermore, the hydrological environment of Dongfengcan be improved by joint operation of the two cascade reservoirs upstream, thus playing a better role in flood control and power generation.