The Real-time Stage Forecasting In The Estuarine Area Of Qiantang River

Because of the unique of Qiantang River's geographical position, the economy has developed better than the inner land. But it is easy to suffer flood, the mission of flood control is rather austere. Aiming at this problem, it is urgent to build a set of perfect mathematic model to make river stage simulation in the estuarine area of Qiantang River. Also we should carry out amendment according to real-time imformation to proceed with the flood operation effectively. It will cut down the enormous economic losses that the flood disaster brings about. The paper adopts current main models for channel flood routing: The one-dimensional hydrodynamic model bases on different solution of St.Venant equations in tidal reaches of Cao'e River and Fuchun River. According to the result and applying, it is pointed out that one-dimensional hydrodynamic model is capable of simulating rather well the dynamic channel flow of flood, but is inapplicable to the regions of insufficient data.Whereas the rigorousness of the one-dimensional hydrodynamic model's data application, Muskingum is used widely for river flood routing in hydrology, which is simple, and of good calculation accuracy. Based on the principle of Muskingum, the flood hydrograph of tidal reach is considered as the overlay of bi-directional propagation of flood wave from upper reaches and tida waves from lower reaches, and the two propagation processes are calculated by stage routing method respectively. Accordingly, the stage forecasting model of the tidal reach is established, and named as bi-direction wave channel routing method. This model is then applied to tidal reaches of Cao'e River and Fuchun River. Compared with the results of one-dimensional hydrodynamic model, the bi-directional stage routing model got a better calculation result with insufficient original data, which proves that it has better flexibility and is simple with clear physical concept. Therefore this model deserves a further research and development.The river stage simulation is highly instability under the various influence from the external environment, so it needs to carry out the stage correcting method. Specifically for the floodland in the estuarine area of Qiantang River, the correction...