“长江2017年第1号洪水”为长江中游区域性大洪水,面对严峻的防洪形势,长江上中游水库群实施联合防洪调度,三峡水库出库流量由27 300 m³/s逐步减至8 000 m³/s,为有史以来最大幅度补偿调度,确保了莲花塘站水位不超过分洪水位。在此期间,莲花塘站洪水预报是决定水库群联合调度启用时机及调度成败的关键因素之一。通过介绍莲花塘站洪水预报方法,分析了2017年长江第1号洪水中莲花塘站洪水预报的成果及误差成因,总结了莲花塘站洪水预报的关键点及难点,从而进一步为防汛决策提供更有力更科学的技术保障。

The “No.1 flood in 2017” is a regional big flood in the midstream of Changjiang River. Reservoir groups in the upper and middle reaches were dispatched jointly to cope with the severe flood situation. The discharge of Three Gorges reservoir reduced from 27 300 m³/s to 8 000 m³/s, which had been the largest compensation ever. The compensation guaranteed that the water level at Lianhuatang station did not exceed the critical stage for flood diversion. Flood forecast for Lianhuatang station is crucial for the determination of joint dispatching time and dispatching effect. In this paper we introduce the flood forecast method for Lianhuatang station, and analyze the forecast result and the causes of errors. In addition, we also summarize the difficult points in flood forecast in the aim of providing more scientific technical support for the flood prevention and decision-making.