浦阳江流域感潮河段洪水预报研究

Study on Flood Prediction of Tidal Reach in Puyang River Basin

浦阳江流域中上游属感潮河段,易受下游洪水顶托影响,导致预报站水位流量关系不稳定,给洪水预报作业带来难度。以诸暨站以上流域范围为研究对象,选用1990—2021年间具有代表性的20场洪水,建立三水源新安江模型,对诸暨站流量进行预报;基于BP神经网络优良的非线性映射能力,建立以湄池水位、时段降雨量、安华水库下泄流量、诸暨站预报流量等为输入因子的诸暨站水位预报模型,以探究该模型在诸暨洪峰水位预报中的适用性。结果证明2019—2021年的场次洪峰水位预报效果较优,场次水位相对误差均保持在2.5%以内。

The middle and upper reaches of Puyang River Basin is a tidal river,which is easily affected by the downstream flood,resulting in the unstable relationship between water level and discharge,which is difficult to the flood forecasting operation.This study took the basin above Zhuji Station as the study area,and 20 representative floods from 1990 to 2021 were selected to forecast the discharge of Zhuji Station by using the three-water source Xin'anjiang model.Based on the excellent nonlinear map⁃ping capability of BP neural network,a water level prediction model of Zhuji Station was established,which took Meichi water level,temporal rainfall,the discharge of Anhua reservoir and the forecast discharge of Zhuji Station as input factors,to explore the applicability in Zhuji flood peak water level forecasting.The results show that the forecast results of the flood peak water level in 2019-2021 is good,and the relative error of water level is kept within 2.5%。