spreval - Evaluation of Sprinkler Irrigation Uniformity and Efficiency
Processing and analysis of field collected or simulated
sprinkler system catch data (depths) to characterize irrigation
uniformity and efficiency using standard and other measures.
Standard measures include the Christiansen coefficient of
uniformity (CU) as found in Christiansen, J.E.(1942,
ISBN:0138779295, "Irrigation by Sprinkling"); and distribution
uniformity (DU), potential efficiency of the low quarter
(PELQ), and application efficiency of the low quarter (AELQ)
that are implementations of measures of the same notation in
Keller, J. and Merriam, J.L. (1978) "Farm Irrigation System
Evaluation: A Guide for Management"
<https://pdf.usaid.gov/pdf_docs/PNAAG745.pdf>. spreval::DU.lh
is similar to spreval::DU but is the distribution uniformity of
the low half instead of low quarter as in DU. spreval::PELQT is
a version of spreval::PELQ adapted for traveling systems
instead of lateral move or solid-set sprinkler systems. The
function spreval::eff is analogous to the method used to
compute application efficiency for furrow irrigation presented
in Walker, W. and Skogerboe, G.V. (1987,ISBN:0138779295,
"Surface Irrigation: Theory and Practice"),that uses piecewise
integration of infiltrated depth compared against soil-moisture
deficit (SMD), when the argument "target" is set equal to SMD.
The other functions contained in the package provide graphical
representation of sprinkler system uniformity, and other
standard univariate parametric and non-parametric statistical
measures as applied to sprinkler system catch depths. A sample
data set of field test data spreval::catchcan (catch depths) is
provided and is used in examples and vignettes. Agricultural
systems emphasized, but this package can be used for landscape
irrigation evaluation, and a landscape (turf) vignette is
included as an example application.