Evaluating whole field irrigation performance using statistical inference of inter-furrow infiltration variation

• Published in: Biosystems engineering Vol. 110; no. 2; pp. 134 - 143
• Main Authors: Gillies, M.H., Smith, R.J., Raine, S.R.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2011; Elsevier
• Subjects: Agricultural machinery and engineering; Agronomy. Soil science and plant productions; Biological and medical sciences; Extrapolation; Fundamental and applied biological sciences. Psychology; furrow irrigation; Furrows; Generalities. Biometrics, experimentation. Remote sensing; Infiltration; Irrigation; Mathematical analysis; Optimization; probability distribution; Statistical distributions; Variability; Statistical method; Bioengineering; Evaluation; Engineering; Irrigation; Field performance; Applied mathematics; Water engineering; Variations; Agriculture; Infiltration; Statistical decision
• ISSN: 1537-5110; 1537-5129
• DOI: 10.1016/j.biosystemseng.2011.07.008

Inter-furrow infiltration variability is often ignored during the evaluation and optimisation of furrow irrigation. Existing techniques for estimating infiltration parameters are generally too intensive in measurement and computation for routine application at the field scale and have therefore primarily been used to study the behaviour of single furrows. This paper identifies the inter-furrow infiltration variation within typical furrow-irrigated fields and determines that this variation can be adequately described using a log-normal distribution. A procedure to predict whole field furrow infiltration characteristics using minimum field measurements is then presented. The technique uses a single advance measurement for single furrows and the log-normal probability distribution to predict the statistical distribution of infiltration functions across the field based on the measured infiltration curve for one or more fully evaluated furrows. This technique also considers the infiltration curve over appropriate ranges of opportunity time. Simulations using the predicted infiltration parameters demonstrate more accurate estimates of the whole field efficiency and uniformity than those extrapolated from infiltration measurements on a limited number of furrows as sampled in a conventional evaluation. ► Inter-furrow infiltration variability is significant. ► Infiltration variability described using the log-normal probability distribution. ► Prediction of soil infiltration at the field scale using limited field data developed. ► The technique facilitates evaluation of furrow irrigation at the field scale. ► The resulting simulations provide improved estimates of irrigation performance.