Elementray Discussion Of Hydrodynamic And Suspended Sediment Distribution Characteristic In The Yangtze Estuary

Based on the hydrological and sediment observations data in the Changjiang Estuary during the dry and flood seasons of 2003 and 2004, analyzed and discussed the temporal and spatial distribution characteristics of hydrodynamic suspended sediment concentrations (SSC). And did further unit width sediment discharge calculation to analyze its characteristics. The results show that the interaction of river discharge and tide current, the inlets terrain and other integrated factors influence the hydrodynamic and suspended sediment concentrations distributions. The main temporal and spatial distribution characteristics are as following.1. The maximum current speed and SSC occour during spring ebb, and the minimum one occours during neap flood. The averaged SSC of all the observation stations is 0.69kg/m~3 in dry season and 0.63kg/m~3 in flood season.2. Current speed and SSC temporal distributiona) Tidal variety distribution: Depth averaged current speed, the gradient of current speed and SSC along vertical direction show spring>neap, ebb>flood; Depth averaged SSC shows spring>neap, and position of its flood and ebb value depend on the season. Tidal variety influence on the current speed in the TM: The North Channel >The South Passage>The North Passage; Tidal variety influence on the SSC in the TM: The North Channe >The North Passage>The South Passage.b) Seasonal variety distribution: Along the inlets, seasonal variety brings unobvious influence on the distribution pattern in the TM. But brings rather more obvious influence on its upper reach and the down reach. Along the cross section. Seasonal variety influence on the current speed in the TM: The North Channel >The South Passage>The North Passage; Seasonal variety influence on the SSC in the TM: The South Passag> The North Channel >The North Passage.3. Current speed and SSC spatial distribution:a) Vertical distribution: The current speed and SSC at 0.4H can figure its corresponding depth averaged value. The flood and ebb current speed and SSC of The North Channe and The South Passage in the flood season in MT show two sections distribution. The section current speed is 1.0～1.5m/s,and SSC is 0.3～0.6km/m~3.b) Plane distribution: Along the inlets from inner to outer mouth, depth averaged current speed and SSC show increase toward TM, and then show decrease toward outer mouth.c) Cross section distribution: depth averaged current speed and SSC: The North Branch>The South Branch; The North Channel is higer during flood in dry season, and The North Passage is lower. The North Passage is higer during neap in dry season, and The North Channel is lower. Current speed of The North Channel and The South Passage are higher in...