Optimization of irrigation technical parameters of brackish water film hole furrow irrigation based on SRFR and Hydrus-3D model

Through the combination of experimental observation and numerical simulation, the surface water flow advance process, soil water, and salt distribution characteristics, and irrigation quality influencing factors of brackish water film hole furrow irrigation were studied, and the technical parameters of brackish water film hole furrow irrigation were optimized. The results show that SRFR model is used to simulate the water flow advance process and Hydrus-3D model is used to simulate the water-salt distribution of film hole furrow irrigation with high reliability, which will greatly help the well-designed of film hole furrow irrigation system. The water flow advance process under the condition of film hole furrow irrigation is in accordance with the power function law, and the flow rate and the aperture ratio have a great influence on the advancing speed of water flow. The brackish water film hole furrow irrigation reduces the evaporation of water, inhibits the salt surface accumulation, effectively regulates the soil water and salt distribution, and has obvious leaching effect on the salt of 0-40 cm soil layer; in order to restrain salt content, the irrigation amount under the condition of film hole furrow irrigation should not be less than 300 m(3)/hm(2). Under the condition of a certain furrow length, the flow rate and the aperture ratio have a significant influence on the irrigation efficiency, the uniformity of irrigation, and the desalination rate. By sorting the influencing factors of irrigation quality of brackish water film hole furrow irrigation, the reasonable combination of irrigation technical parameters of brackish water film hole furrow irrigation in the test area is proposed, and the optimal combination of irrigation technical parameters of brackish water film hole furrow irrigation is obtained. The aperture ratio is 3%, the furrow length is 70 m, the flow rate is 5 L/s, and the irrigation time is 11.9 min.