Hydrodynamic Studies To The Tidal Current And Suspended Sediments In The Channels Of Jiangsu Radial Sand Ridges

On the basis of analyzing the two tidal periods successive survey results on the tidal current and suspended sediment at 4 station in the tidal channel called DongDaGang , the characters of tidal current and the rule of suspended sediment change are further studied, the surveyed suspended sediment concentration data were fitted to the relative depth, the vertical distributing character of suspended sediment was discovered. Also on the basis of analyzing the two tidal periods successive survey results on the tidal current and suspended sediment at No.5 station in the tidal channel at the crunode of DongDaGang and Dayaomen tidal channel , the tidal characters and process of suspended sediments are further understood. The two main vertical distributing form of suspended sediments are discovered and the corresponding fitting relationships are made certain. The interaction between sea topography and tidal current is analyzed and studied in the article.Suspended sediment concentration in the water exhibits a complicated non-linear dynamical process in the tidal channel.Seeing that artificial neural network possesses the capabilities of dealing with complex non-linear dynamial systems,this paper demonstrates how it can be used in suspended sediment concentration and sediment transport prediction as a new approach by considering the non-linear relationship between sediment,sediment transport and its affecting factors. The Back Propagation(BP) model of artifical neural net works is applied to predict sediment concentration and its transport in No.4 station.The simulating and predicting results show the BP model not only possesses high accuracy of fitness but also attains precise prediction as well.Based on the field data of flow and sediment at No.4 station in Dongdagang tidal channel, the component items of suspended sediment transport are analysed and studied the by the mechanism decompose method, It comes to the conclusion that there exist significant tidal pumping effect and strong exchange between suspended load and bedload during the transport process.spectral analysis and wavelet analysis are also applied to analyse the fluctuations of the suspended sediment concentration,tidal flow velocity and sediment transporation. The result shows that the sediment transportation is primarily affected by tidal flow only in lower-frequency, and the closed correlation exists between velocity and suspended sediment in high-frequence, which is considered to be very important for sediment transportation.On the basis of analyzing the two tidal periods successive survey results on the tidal current at No.4 station in the tidal channel called DongDaGang, the characters of tidal current and space distributing of current vector are further studied. The vertical distributing of current velocity is studied and the surveyed current velocity data are fitted to the relative depth. The vertical distributing relationship between velocity and relative depth is discovered. Based on the surveyed current velocity data, the remainder current functions of six water layers are calibrated by fitting method. The remainder current function term is the function of friction velocity and relative depth. The relationship between the remainder current functions and suspended sediment concentration & its vertical grads are discovered. The relationship is only formal connection not the direct dynamical consequence. The remainder current functions and the suspended sediment concentration & its vertical grads all are the results of hydrokinetics.Based on the current velocity and corresponding current direction data of water flow at No.4 station in Dongdagang tidal channel, current velocity and its direction of each layer is simulated and predicted by the Back Propagation(BP) model of artificial neural net works. The simulated and predicted results show the distribution and tidal processes of current velocity and its direction are predictable with velocity and direction of surface layer & water depth by the BP model.On the basis of analyzing the two tid...