关键词: 水文预报, 降水预报, 入库洪峰流量预报, 水文模型, 水文气象耦合, 长江2018年第2号洪水, 三峡水库

Abstract: During the early to middle of July in 2018, two numbered flood continuously occurred in upper Yangtze River (the No.1 and No.2 floods in 2018 of Yangtze River), and extra-large flood over 50-year frequency occurred in the partial tributaries of upper Yangtze River during the No.2 flood. The water level was over the guaranteed level in Tuojiang River, Fujiang River, lower reach of Jialing River and Cuntan reach of upper Yangtze River, and the flood peak flow entering TGR reached 60 000 m3/s. Hydrology Bureau of Changjiang Water Resources Commission had successfully forecasted the two numbered flood by coupling multi-hydro-meteorological model and multi-methods. This paper evaluated the hydrological forecasting accuracy published by Hydrology Bureau during the No.1 and No.2 flood from two aspects of short-medium term quantitative forecast and flood forecast. The results show that the heavy rainfall was forecasted and warned 7 days in advance for the two floods, 50 000 m3/s flood peak entering TGR was forecasted ahead of 4d for the No.1 flood and 60 000 m3/s flood peak entering TGR was forecasted ahead of 3d for the No.2 flood. The high forecast accuracy and long effective forecast term of flood provided important technical support for scientific operation decision of flood control.

Key words: hydrological forecast；precipitation forecast；flood peak forecast, hydrological model, hydro-meteorogical coupling, No.2 flood in 2018 of Yangtze River, Three Gorges Reservoir