汛限水位动态控制是水库洪水资源化的一种重要策略,其核心是在合理权衡风险和效益这一对矛盾的基础上确定可行的水库超汛限水位调度方案。为实现相对较大效益的同时降低水库防洪风险,考虑利用流域降雨预报信息,采用预泄能力约束法,以不同的降雨预报量级为依据,提出分级超蓄的洪水资源化方法,并结合安康水库实例,求得其基于24h小雨和无雨预报的分级超蓄上限分别为326m和328m。通过风险分析得知:在不考虑降雨预报信息的情况下,水库超蓄上限不宜超过327.5m;而依据24h降雨预报信息的水库超蓄风险小到可以忽略。最后,应用该超蓄方案对实际洪水进行调度,实现了在减少弃水量0.69亿m^2的同时,增加发电收入约361万元人民币。
Dynamic control of the limit water level is one of effective strategy to utilize floodwater resources,which key problem is to work out a feasible over storage operation scheme based on rational weighing the contradictory of risk and interest. For more benefits and lower risk, precipitation forecast information was taken into account in this paper, and a method of grading of flood control level for floodwater resource utilization was put forward based on pre-discharge capability constraint method. Then,the method was applied to Ankang reservoir for flood water resource utilization, the grading control water level was 326 m and 328 m respectively by calculation when the 24-hour-forecast rain intensity was 0. 1 mm to 10 mm and 0.1 mm below. Furthermore, risk analysis indicates that the flood control level could not be over 327.5 m in the case of without regard to precipitation forecast information, but the risk could be ignored if 24-hour-forecast precipitation was taken into account. Finally,the scheme was applied to Ankang reservoir for a real flood operation, the benefit analysis indicates that it will bring about 361 thousands RMB of extra power generation interests at the same time cutting abandoned water 69 million m^3. Therefore, it is proved that the application of the method has favorable effects not only on risk control but also on benefits increment in floodwater utilization.