Abstract
The infiltration types of film hole irrigation (FHI) can be divided into film hole free infiltration (FHFI) and film hole interference infiltration (FHII). Numerical simulations were carried out with HYDRUS to investigate the influence of soil texture (ST), film hole diameter ( D ), film hole spacing ( S ) and water depth above the film hole ( H ) on the cumulative infiltration under two infiltration types of FHFI and FHII. The results showed that the amount of FHII was reduced significantly compared to that of FHFI. ST, D and S are the dominant factors affecting the infiltration reduction volume (Δ I ). The relationship between Δ I and the time after interference ( t − t 0 ) is a proportional function ( R 2 ≥ 0.96), and its proportional coefficient has a good power function relationship with D and S . The power function coefficients have large differences for different ST, and the range of variation is 0.1–191, whereas there is little difference between the power function index of D and S ; the average values were 2.6 and −2.5, respectively. A simplified calculation model of infiltration reduction was established, and the estimation accuracy was high (RMSE = 0.017 L, EF = 0.980). This research can provide a reference for the calculation of the irrigation water volume of the FHI.