Influence of runoff on tidal wave deformation and propagation in tidal reaches of Changjiang River
Due to the interaction of runoff and tidal current,the deformation process of tidal waves along the tidal reach of the Changjiang River is complicated during the propagation of tidal waves from the estuary to the upstream.In this paper,based on the measured data of high and low tidal levels and tidal time in the tidal reach of the Changjiang River and the daily average flow data at Datong station,the relationship between tidal eigenvalues and tidal wave propagation eigenvalues with flow in the tidal reach was analyzed by mathematical statistics,Hermit interpolation and wavelet analysis.The results showed that the high,low tide level and average water level increased with the increasing of flow rate,and the more far to the downstream,the lower the sensitivity to flow rate was.The tidal range of the upper reaches of the Jiangyin reach decreased first and then increased with the increase of flow rate.The influence of runoff on the amplitude of tidal constituents was more obvious in the upper reaches of Jiangyin Station.The ampli-tude of semi-diurnal tide and diurnal tide decreased first and then increased with the increase of discharge,and the amplitude of quarter-day tidal constituents decreased with the increase of discharge,among which the amplitude of semi-diurnal tide changed the most.The average water level slope increased first and then decreased with the increase of flow rate in Wuhu-Ma'anshan reach,however it was positively correlated with the flow rate in the lower reaches of Ma'anshan Station.The attenuation rate of tidal wave amplitude increased first and then decreased with the increase of flow rate.The closer to the estuary,the greater the flow threshold was.The research results are helpful to understanding the mechanism of tidal interaction in river mouth,and can also pro-vide scientific guidance for estuary management.
tidal reachtidal wave propagationrunofftide constituent amplitudemean water level slopeattenuation rate of tidal waveChangjiang River
国家科技期刊平台
NSTL
万方数据
维普
