钱塘江河口洪水特性及动床数值预报模型

在分析钱塘江河口水文、地形及洪水位实测资料的基础上,得到了钱塘江河口段潮汐、径流、河床三者的非线性关系对河口段的洪水位有显著影响的规律,以此为基础建立了洪水预报的一维动床数值预报模型。模型复演了钱塘江河口一次典型的洪水位过程,并利用动床模型和定床模型的两种计算模式对各站洪水位进行了比较,两种模式计算得到的沿程洪水位可差03～20m,但动床模拟与实测过程十分吻合,表明在象钱塘江河口这样大冲大淤的洪水位预报中考虑动床冲淤过程是必要的。

Characteristic of the flood level in the Qiantang Estuary and mobile-bed model for forecast

Based on the observed hydrologic and topographic data, it is found that the non-linear properties of tide, runoff and topography in the estuary have a great influence on flood level. Therefore, one-dimensional unsteady mobile-bed mathematical model has been developed to forecast the flood level of the Qiantang Estuary. Even the extreme flood events in Qiantang estuary in 1997 are well simulated. In Qiantang Estuary, it is necessary to consider mobile-bed scouring process in flood forecast because the peak flood level simulated by fixed-bed model would be 0.3m to 2m higher than the measured while mobile-bed model could get more close results to the measured process.