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

This function determines PELQ as the average of the low quarter catch rates divided by the average catch rate 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 rates).

PELQ(x,SI=TRUE,rate,ss,sl,dur)

Arguments

x

numeric array of catch can depths.

SI

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

rate

sprinkler discharge rate (lpm or gpm).

ss

sprinkler spacing (m or ft).

sl

lateral spacing (m or ft).

dur

duration of irrigation event, hr.

Details

catch can depths converted to catch rates.

Value

PELQ (potential application efficiency of low quarter, %

References

Mirriam and Keller, 1978. Farm System Irrigation Evaluation: A Guide for Management. PP 41-43. Utah State University, Logan, Utah. https://pdf.usaid.gov/pdf_docs/PNAAG745.pdf

Author

Garry Grabow glgrabow@ncsu.edu

See also

PELQT,AELQ

Examples

#see pp 41-43 of reference document
SI<-FALSE # use U.S. customary units
x<-c(.23,.31,.24,.24,.28,.31,.27,.22,.26,.31,
.31,.25,.20,.22,.32)# catch can depths caught during test converted to in/hr
rate<-4.6 # 4.6 gpm sprinkler discharge rate (measured)
sl<-50; ss<-30 # 30 x 50 ft sprinkler x lateral spacing
dur<-1 # 1 hr test duration (dur. in min)
PELQ(x,SI=FALSE,rate,ss,sl,dur)
#> [1] 73.64892