Seasonal Tidal Dynamics in the Qiantang Estuary: The Importance of Morphological Evolution

Despite the increasing number of studies on river-tide interactions in estuaries, less attention has been paid to role seasonal morphological changes tidal regime. This study analyzes interplay river and tide Qiantang Estuary, China, particularly focusing influences active evolution induced by variation discharge. The is based high low water levels at three representative stations along estuary daily discharge through 2015, an intermediate flow year which a typical flood occurred, as well bathymetric data measured April, July November, 2015. results show strong variations level addition spring-neap variation. These are obviously due interaction between but can only be fully explained including effect changes. Two types dynamics distinguished: one immediately other continues for much longer period because bed erosion following recovery. Tidal range upper reach doubled after then decrease under normal periods sediment accumulation. Over relatively short term such month or cycle, there exist good relationships range, amplification mouth, hydraulic head over lower reaches. Such unclear if all whole considered together, mainly evolution.