基于下游河道过流能力分级的水库洪水预报调度方式研究

Research on flood forecast operation model based on the classification of flood diversion capacity of downstream reaches

对于某些下游有防护任务且防护目标距离入海口较近的水库,经实际分析,由于河道糙率、潮汐、洪水地区组成的影响,其下游河道的过流能力较设计值有较大的变化。而已有的预报调度方式是将其概化为定值进行设计的,这给实际的洪水调度带来了一定的风险,即:当河道实际防洪能力降低时,即使出现的是防洪标准洪水也会引起一定的上下游淹没损失;相反地,当实际行洪能力较设计情况有所提高时,若仍按原调度方式提前泄流,就会造成洪水资源的极大浪费。针对此类情况,本文以碧流河水库为研究背景,建立了基于水库下游河道行洪能力分级的预报调度规则,随后的实例分析阐述了新预报调度规则的确定过程,并通过对几场典型洪水进行调节来验证该预报调度方式的合理性与可行性。

There are some reservoirs with the task of flood control near by the entrance of the sea, the flood diversion capacity of downstream reach may be uncertain, which varies with the following factors, such as bed roughness, tide, sea-wind and so on. However, the flood control forecast operation rules are established by taking it into account as an invariant. While the flood diversion capacity of downstream reach becomes flowing, we will bear great economic loss because of releasing floodwater ahead of schedule. Aimed at those situations, with the background of Biliuhe reservoir, a new flood control forecast operation model is developed based on the classification of flood diversion capacity of downstream reach. To further attest its feasibility, the new model is developed. The results show that the model is useful and rational.