# Evaluation of Sprinkler Irrigation Uniformity and Efficiency

## Brief Description of spreval package

The spreval package contains a number of functions to assess irrigation sprinkler system application uniformity and efficiency. Use of the functions allow for assessment of lateral-move, solid-set, and hose pull (big gun) irrigation systems. Assessment of landscape sprinkler irrigation systems may also be done using functions contained in the package. The description at the top of the package’s CRAN page provides more detail and background. spreval::catchcan is a data file included in this package. Methods implemented in this package and data used in the vignettes are taken from the references below:

## References

Christiansen, J.D. 1942. Irrigation by Sprinkling. California Agricultural Experiment Station Bulletin 670. (https://archive.org/details/irrigationbyspri670chri/page/n3/mode/2up)

Evans, R.O., Barker J.C., Smith J.T., Sheffield R.E. 1997b. Field calibration procedures for animal wastewater application equipment, hard hose and cable tow traveler irrigation system. NC Cooperative Extension Service publication AG-553-2. Raleigh, NC. (https://content.ces.ncsu.edu/hard-hose-and-cable-tow-traveler-irrigation-systems)

Evans, R.O., Barker J.C., Smith J.T., Sheffield R.E. 1997a. Field calibration procedures for animal wastewater application equipment, stationary sprinkler irrigation system. NC Cooperative Extension Service publication AG 553-1. Raleigh, NC. (https://irrigation.wordpress.ncsu.edu/files/2017/01/ag-553-1-stationary-sprinkler.pdf)

Mirriam and Keller, 1978. Farm System Irrigation Evaluation: A Guide for Management. Form II-1, item 10, p.29. Utah State University, Logan, Utah. (https://pdf.usaid.gov/pdf_docs/PNAAG745.pdf)

## Installation

You can install the newest released version of spreval (release data 2022-03-23) from CRAN with:

install.packages("spreval")

or you may access from the “Links” listing on this page, or navigate to the github repository page and click under “releases” to download the source code and install locally.

A pdf file documenting all of the package functions is available at: here

Check the changelog tab for updates on version history.

## Example

A quick example of a couple of things this package will do is shown below. In this example, conventional statistics, e.g., CU, DU, DU low half (DU.lh), and PELQ are computed. Additionally, a cumulative distribution plot of the data are shown with a target depth (sfplot) to help visualize the relative area receiving less than or more than the target depth, and the deviation from the target depth is shown. For perspective, the top of the plot can be considered as the soil surface and the cumulative distribution line the depth of catch:

library(spreval)
## basic example code
data("catchcan")
cc.data<-catchcan\$solid.set #fetch solid set data
ss.uni<-c(CU(cc.data),DU(cc.data),DU.lh(cc.data),PELQ(cc.data,SI=FALSE,rate=16.98,ss=80,sl=80,dur=2.25))# use U.S. cust. units
table<-round(ss.uni,0)
knitr::kable(t(table),col.names=c("CU","DU","DU.lh","PELQ"))#transpose array (table) for display
CU DU DU.lh PELQ
75 55 76 55
sfplot(as.vector(cc.data),target=0.57,ylab="depth caught, in.")