Design And Verification Of Local Physical Model For Reservoir In Lower Sediment Rivers

The rivers in the southwest of China have the characteristics of the larger river average ratio drop,the wide range of flood and dry flow,the deep river valley and the complex terrain,and the river sediment transport is uneven in the year,mainly concentrated in the flood season,and the sand peak appears with the flood peak.A water supplement project in Southwest China is a key project for comprehensive control of water environment in this area.In the process of actual operation,there is a significant increase in sediment concentration in the flood season than in the dry period,and the turbidity of the water intake of the water intake port has a great influence on the river landscape and water environment.Through the earlier stage flume test,the model sand was compared and selected to get the model sand suitable for this test.Using the selected model sand to simulate the formation of low sediment density current,we explored the characteristics of head velocity variation along the downstream flow of low sediment laden and turbid water.Based on the previous work,the calculation formula of head velocity is selected in accordance with the characteristics of this test.The result of the channel test is in good agreement with the former theoretical formula of head velocity.Based on the predecessors' research basis,the advantages and disadvantages of the plunging point formula of different reservoir density current are analyzed.The formula of the plunging point of the reservoir density current is corrected and verified by the measured data.The calculation results show that the position of the latent point of the gravity current is close to the prototype observation position,and can be used for the latent and formation prediction of the gravity flow.According to the river model test regulations and the research results of the reservoir physical model similarity law,the physical model is designed and made according to the characteristics of the water and sand and the boundary conditions of the research objects.The representative water and sediment process,the corresponding river boundary and the reservoir scheduling are selected to verify the model,and the water and sediment change and the prototype reflected by the experimental results are reflected.Similarly,the established solid model can be applied to this experimental research.