三峡水库动态汛限水位洪水调度风险指标及综合评价模型研究

Risk criteria and comprehensive evaluation model for the operation of Three Gorges reservoir under dynamic flood limit water level

汛限水位是综合利用水库运行和调度的重要参数之一,也是协调防洪和兴利矛盾的焦点所在。现行的汛限水位过多地考虑了小概率洪水事件,不能充分挖掘水库汛期的兴利效益,因此,采用动态汛限水位进行调度,对综合利用水库的运行具有重要的理论意义和实用价值。根据三峡水库围堰发电期的调度规程,建立预报预泄调度模型,采用宜昌站1882-2001年汛期实测日流量资料,实现了考虑预报信息的动态汛限水位洪水调度模拟;提出了多目标风险指标体系;计算了9种动态汛限水位方案下的风险指标值,通过综合评价模型对各方案进行比较和优选,得到了相对合理的动态汛限水位方案。

As a key parameter of multi-purpose reservoir operation, flood limit water level plays a critical role in achieving the balance between flood control and economic benefit such as hydro-power generation and navigation improvement etc. The currently adopted flood limit water level pays too much attention to the floods of low probability, thus reducing the economic benefit of the reservoir during the flood period. It is theoretically and applicably essential to adopt a dynamic flood limit water level in the operation. According to the general operation rules of Three Gorges Reservoir (TGR), a real-time model under dynamic flood limit water level is developed and used to simulate the TGR operation by using the daily river flow series of the Yichang gauging station about 40 km downstream to the dam site of the TGR during the period of 1882-2001. The multi-objective criteria and a comprehensive evaluation model are proposed and developed to measure and assess the TGR operation risks. The optimum scheme is obtained by comparing nine alternatives of dynamic flood limit water level schemes.