Transport Characteristics Of Yellow River Sediment And Analysis Of River Scouring And Silting Patterns

The amount of sediment in the Yellow River is the highest in the world,its high sediment concentration has become an important reason for river migration,shrinkage,siltation and riverbed elevation.This paper takes the upper and lower reaches of the Yellow River in Inner Mongolia as the research area,through field experiments and laboratory experiments,combined with the hydrological data from Toudaoguai hydrological station,the basic motion characteristics of sediment,the movement characteristics of sediment transport during sedimentation period and the law of sediment transport was studied,combined with measured terrain data,the migration process of the sediment is simulated.Through analyzing the results of calculation and simulation,we know the water flow characteristics,sediment characteristics and sediment transport law of the upper and lower reaches of the Yellow River in Inner Mongolia.The roughness of the Yellow River Inner Mongolia Tuo County is decreasing from the upstream to the downstream river and the variation is small,the velocity of the flow is exponential.The sedimentation velocity of suspended sediment in the river is much smaller than that of the water flow,suspended sediment will not be deposited in the river,and bed sand in a certain hydraulic conditions can start and occur suspension movement.The hydraulic characteristics of the river during the ice season will change,the flow rate is double logarithmic,over-current capacity weakened,river sediment transport rate reduced.During this period,the amount of sediment is affected by the thickness of the ice sheet,the conditions of the river regime and the form of the seal.And ice thickness has a greater impact on sediment concentration,showing the vertical distribution of sediment concentration is uneven,the spatial distribution at the corners changes greatly,in the straight river changes smaller.In general,the water holding capacity and sediment transport rate are smaller in the freezing period and the dry season than in the wet season,and the sediment transport rate increases along the direction of water flow,and Shenquan River water carrying capacity is greater than the Toudaoguai and the Juhe beach.HEC-RAS software hydrodynamic simulation study area water flow are consistent with the measured Toudaoguai station hydrological data in a higher degree,the simulation results are better,sedimentation capacity simulation accuracy is more than 84%,the simulation results are better,the model can be applied to the sedimentation rate under different flow conditions in the study area and the simulation of Bed Shear Force and River Serdiment Change in River Bed.According the simulation results,In the simulation time sequence,the river starts in the upper reaches of the Shisifenzi and end in the Juhe beach,the river is generally silted,the spatial variation of shear force and the velocity of sediment show an increasing trend,but in the corners and the river beam narrowing occurred in the erosion.