A Preliminary Study On Bed Load Transport In Tidal Reach Of The Yangtse River

Bed load is a main part of river sediment. Its amount is much less than suspended load, but its movement is closely related with scour and fill of riverbed. So it is very important to study on the rules of bed load for irrigation works and harbor and waterway engineering.Study on bed load in tidal reach of the Yangtze River is not enough. Estuary is more researched. So the rule of bed load transport in reach from Datong to Xuliujing is not realized well. And because of the influence induced by climate change and human activities, including warming up of the world,hydraulic works being constructed such as The Gorges Dam> north dispatch of the Yangtze River water and great increase of water by industry and agriculture, all these factors result in the change of flow and sediment. So it is necessary to study the rule of bed load transport in reach from Datong to Xuliujing.Data of flow and sediment in tidal reach of Yangtze River is summarized and studied. By using the 2-D numerical model of flow, hydrodynamic conditions are simulated. An appropriate formula of bed load rate is chosen to calculate the amount of bed load of each section. Curves of amount of bed load and discharge are got. Rule of bed load transport in tidal reach of the Yangtze River and distributing rule along the river are studied. Relationship between bed load transport and tide and relationship between bed load transport and flow velocity are got and studied. Influence on bed load transport by change of flow and sediment from upstream of the Yangtze River is researched. While these influence factors include water abstraction along the river,coarsening of river bed and reservoir regulation.