Abstract：Aiming at the disadvantages of traditional straight-line desilting basin, such as low sediment removal rate, weak adaptability and large footprint area, based on sediment deposition cha-racteristics, flow characteristics and sediment distribution characteristics in the tank, the drainage section and overflow weir were improved. Combined with the principle of eddy current sediment ejection, vortex tubes were set at the back of overflow weir to achieve double desilting. A physical model was built to test the flow velocity, sediment grain size and concentration at different points of the desilting basin, and to study the sediment variation law by distance and the underflow rate of the double desil-ting basin. The results show that single trial sediment is mainly bed load sediment, and the quantity of precipitate is more than 95%. The second trial sediment is mainly suspended sediment load, which is increased by 12.70% and 18.80% compared with the desilting basin without spillway trough and vortex tube. The total bed cleaning efficiency of the system can reach more than 96.88%, which greatly improves the underflow rate of sediment in the pool. It fully shows that the improved desilting basin can significantly improve the sediment settling effect, and the research results can provide some technical support for the large-scale application of micro-irrigation engineering.
