The Study On Characteristic Of Sediment Transport In BaoTou Deng Kou Pumping Irrigation District Main Channel

Over the years, channel deposition in the Yellow River irrigation area has been an important factor influencing the development of the irrigation area. By taking the main canal of Baotou Dengkou pumping irrigation area as the research object, this article analyzes the sand-carrying capacity, flow sand-carrying capacity, spatial-temporal change and total transport rate of each section for the main canal lined in 2015, and makes a theoretical analysis of sediment movement characteristics of the main canal combined with the flow, flow rate and other relevant information of the main canal according to the related theories of sediment movement.Main contents of this research included an in-depth study of the path and spatial-temporal change rule of the sand-carrying capacity, sediment transport characteristics, sediment deposition and movement as well as the vertical distribution of sand content for the main canal, the results showing that:(1) After analysis from the spatial-temporal change of the sand content in the main canal, it was concluded that:From the perspective of the path change, the sand content declined along the path from the water outlet to the end of the main canal during the spring irrigation period with basically little change during the other three irrigation periods, indicating that such three periods reached the fluvial equilibrium; in terms of the temporal change, the sand content of the spring irrigation period was more than that of the other three irrigation periods.(2) A study on the sediment grading, deposition and movement speed of the main canal found that there were many factors influencing the sediment deposition and movement, but the main factors included the size of median particle in the suspended sediment and other relevant hydraulic characteristic conditions.(3) After the vertical distribution theory of the unbalanced sand content was applied, it was found that the san’d content of the main canal during each irrigation period was distributed along the vertical line. The vertical distribution of the main canal during the former three irrigation periods adopted the Ⅱ type distribution while that during the autumn irrigation period adopted the I type distribution. (4) In terms of the sand-carrying capacity of the main canal, it was the largest during the autumn irrigation period followed by that during the summer and spring irrigation periods. The sand-carrying capacity ratio formula conducted enabled the irrigation management department to determine the flow of sand-carrying capacity (not flushed and deposited) for the main canal timely based on the inflow sand content.