Study On Characteristics Of Water And Sediment In Zun-cun Irrigated Area Of Yellow River Diversion

After years of development,the siltation of canal system in the irrigation area of Yellow River is still a serious problem,which affects the normal operation and development of irrigation area.In order to alleviate the problem of channel siltation and provide technical support for the operation mode of irrigation district dispatching,this paper takes the two trunk channels of the Yellow River irrigation area of Zun-cun village as the research object,taking the discipline of sediment dynamics,hydraulics,and farmland water conservancy as the technical support,and adopts the technical hand section of investigation and analysis,data analysis and so on.,The distribution law of water and sediment,the movement rule of water and sediment,the sediment carrying capacity and the scouring and silting of two main canal in 2016 years were systematically analyzed.The results of the study show that:(1)The changing trend of flow velocity at different points in different sections is generally the same,but the regularity of the change along the path is not obvious;the sediment content in the channel along the path is not much changed,the right bank concrete slab lining and the left bank are not laid.Except section II,the suspended sediment content in the right bank is lower than that on the left bank,and the water demand in different seasons is different and the water diversion season is different in different seasons.The proportion of sediment diversion in water diversion is also different,and the sediment concentration in summer irrigation is about 2-3 times that of spring irrigation,and the change of the suspended matter and the path of the passage of the plasmids is related to the flow velocity and the sediment content of the water.(2)The main factors affecting the sediment carrying capacity are the flow rate,the sediment content of the water and the particle size of the sediment.When the flow rate is less than 10 m~3/s,the sediment content changes little,and the sand carrying capacity increases with the increase of the flow rate;the changing trend of the sediment carrying capacity in different sections of different irrigation periods is basically the same,but there is no obvious change law.The canal’s sediment carrying capacity of summer irrigation is larger than that of spring irrigation.(3)This paper uses the HEC-RAS model to simulate the water and sediment in the second culvert canal in Zuncun Irrigation District.The simulated water level and flow of the channel are in good agreement with the measured water level and flow,and the simulation results are better.The simulated accuracy of the sediment transport capability reaches over 80%.The simulation results are better.The model can simulate the sediment.The model can be applied to the simulation of the sediment movement rate,channel bed shear force,and bed sediment concentration under different flow conditions,including the channel section type is trapezoidal section,the channel slope coefficient is0.70,the bottom width is 5-7m,the channel water depth is 3-4m,the sediment concentration is 0.7-0.9kg/m~3,and the flow range is 8-12m~3/s,and the flow rate ranges from 0.8 to 0.9 m/s.