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原文传递 INFLUENCE OF SALT WEDGE PENETRATING UPWARDS THE RIVER UPON WATER FLOW VELOCITY AND SEDIMENT TRANSPORT RATE

题名：	INFLUENCE OF SALT WEDGE PENETRATING UPWARDS THE RIVER UPON WATER FLOW VELOCITY AND SEDIMENT TRANSPORT RATE
作者：	Zygmunt MEYER; Ryszard COUFAL; Ma.gorzata PLUTA
关键词：	SALT ; RIVER WATER FLOW VELOCITY ; SEDIMENT TRANSPORT RATE
摘要：	The flow, in which the fresh water from the river gets mixed with the salt one, is characteristic feature for the estuarine river sections. This is a typical example of density stratified flows. The conditions of fresh and salt water mixing and the range of the salt water wedge, which penetrates upwards the river, depend mainly on the river flow, sea level, wind velocity and direction. The salt water wedge influences significantly the distribution of flow velocities (usually it makes them increase) as well as sediment transport rate that silts up the water fairway. In the Oder River estuary the range of sea surge influence is big, due to small water level slopes. After strong stormy freshets, when salt water flows in the Szczecin Lagoon from the sea, the salt wedge is noticed even at Police cross-section (50 km away from .winouj.cie). However, even if there is not sea surge, there exist water of big salinity at the lower layers of the .wina River and Szczecin-.winouj.cie fairway. The paper presents the model of sediment transport at the river mouth in case of density stratification when the salt water wedge develops. The mathematical description of the problem is based upon the mathematical model of vertical circulation in density stratified flow elaborated by Meyer. The intensity of the sediment transport rate in the river was calculated by the means of Ackers-White's method, which make its values dependent on the average velocity, shear velocity and sediment-characterising parameters. The calculations were carried out for the steady conditions assuming that there is a continuity of flow and sediment transport rate. The presented model allows calculating such elements of water motion as: flow velocity components, location of distribution surface separating the upper flow area, shear velocities, range and shape of salt wedge penetrating upwards the river and intensity of sediment transport rate in the area of river main flow. The obtained results indicate that: - the salt water wedge makes flow velocities in the transit area higher, what can impede the navigation, - the existence of salt wedge does not make either sediment accumulate or river get shallow in the estuarial area, the wind – changing the bottom and surface circulation areas – influences significantly upon the shape and range of salt wedge penetrating upwards the river.
总页数：	Proceedings of the 30th PIANC-AIPCN Congress. Sydney Australia. 22-26 Sept. 2002. pp13
报告类型：	科技报告