PELQT {spreval}

Potential application efficiency of low quarter for a traveling irrigation system.

Description

This function determines PELQ as the average of the low quarter catch depths divided by the average catch depth of applied water. As such is is a measure of the potential of the sprinkler irrigation system considering uniformity (low quarter) and any losses due to drift and evaporation (uses catch can depths overlapped at specified lane spacing).

Usage

PELQT(x,SI=TRUE,rate,ls,ts)

Arguments

x

numeric array of catch can depths, overlapped.

SI

logical; units SI (mm, m, lpm) or US Customary (in., ft, gpm). SI (TRUE) is default.

rate

sprinkler discharge rate (lps or gpm).

ls

lane spacing (m or ft).

ts

travel speed (m/min or ft/min).

Details

catch can depths overlapped to specified lane spacing.

Value

PELQT (potential application efficiency of low quarter for traveling system, %

Author(s)

Garry Grabow [e-mail]

References

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://p2infohouse.org/ref/32/31084/ag-553-2.pdf

Liu, Z., G.L. Grabow, R.L. Huffman, J. Osborne, and R.O. Evans. 2012. Factors Affecting Uniformity of Irrigation-Type Manure Application Systems. Applied Eng. in Agric. 28(1):43-56.

Mirriam and Keller, 1978. Farm System Irrigation Evaluation: A Guide for Management. PP 97-107. Utah State University, Logan, Utah. https://pdf.usaid.gov/pdf_docs/PNAAG745.pdf

See Also

PELQ,travunif

Examples

#see pp 41-43 of reference document
SI<-FALSE # use U.S. customary units
left<-c(0.94,0.80,0.59,0.61,0.50,0.42,0.33,0.07)
right<-c(0.73,0.81,0.92,0.64,0.50,0.27,0.20,0.13)
ls<-224;gs<-20
#first call travunif to return overlapped data given gage spacing and lane spacing
out<-travunif(ls,gs,left,right)
x<-out$o.depths
rate<-197 # 197 gpm sprinkler discharge rate (measured)
PELQT(x,SI=FALSE,rate,ls,1.5)#call PELQ for traveling systems