Abstract:

Base on the annually observed current data at a representative point in the Lingdingyang Estuary, the authors dis-cuss the vertical profiles’ variation of residual currents and its correlation with runoff volume. It is found that the residual currents had an obvious vertical stratification of upstream current and drainage and that the thickness of upstream current and drainage assumed a periodic variation during the year. The actual runoff volume had a good linear relationship with the flow rate of the local surface current. It, however, had no obvious linear correlation with the bottom upstream; instead, it had a good exponential correlation with the bottom upstream. The upstream was small during seasonal transition, while it was large in flood and dry seasons. The average vertical transport of residual currents was different in each month, pointing to downstream in summer but to upstream in other seasons, and had more relations with the runoff volume of the Pearl River. The transport of Euler Residual Current was pointing to upstream for the whole year.

Key words: Pearl River Mouth, Lingdingyang Estuary, residual current, vertical distribution