Abstract:Uniformity coefficient of sprinkler irrigation is an important indicator for measuring hydraulic performance and irrigation quality of sprinkle irrigation system. In order to investigate the influence of the catch-can space, grid space and interpolation methods on the christiansen uniformity (Cu), Cu was computed by linear interpolation, cubic interpolation, cubic spline twice interpolation, inverse distance weighting method and plane interpolation method with 1 m and 2 m sampling spaces, and 1m and 0.5 m grid spaces. The experiment was preceded indoor with no wind for the single sprinkler Nelson R33. The data here used to compute the Cu were measured in catch cans along one radial leg from the sprinkler position. The results showed that Cu computed from 2 m space catch-can data were less than that from 1 m space catch-can data by 1.3%~3.4%. Smaller the grid space was, greater the Cu was, with deviations all less than 1.2%. The Cu calculation results by linear interpolation, cubic interpolation, cubic spline twice interpolation and inverse distance weighting method were very close to each other. However, Cu showed great difference when using the plane interpolation method with the other methods. The orthogonal test of variance analysis method was used to analyze the factors which influence the result of the Cu. The results showed that the influence of catch-can space, grid space and interpolation method on Cu was less and less in turn.