Models of Kelvin Tidal Waves in the Lingdingyang Region, Pearl River Estuary, South China

The Lingdingyang region has complicated topography with channels, shoals and tidal flats. There are freshwater seasonal inputs from four river branches and unequal semi-diurnal tides. This paper summarizes a simplified two-dimensional analytical model of the estuary. The analytical model represents the flow in terms of partially reflected Kelvin waves. There are phase leads for the currents and phase lags for the salinity variations relative to the tidal height. Further important features appear in the three-dimensional model. The tidal waves are distorted in shallow water by non-linear effects. The flood currents are stronger than the ebb currents in the eastern part and vice versa in the western part of the estuary. Stratification is important in the deep channels and the direction of flow in the channels is strongly influenced by the drying up over tidal flats