Drip Irrigation Design
I-Pai Wu
University of Hawaii

A computer design program. Click on the picture and down load a self extracting computer design program. After downloading the program in a new directory simply type drip_des.exe to extract the program and then type start to begin the program.

1.For hydraulic design only, the correlation between UCC (Christiansen Uniformity Coefficient) and CV(Coefficient of Variation)is:.
UCC = 1 - 0.87 CV
R**2 = 0.998
The correlation between CV and qvar(emitter flow variation) is:
qvar = 0.0043 + 3.0378 CV - 3.8941 CV**2
R**2 = 0.997
The 90% UCC is about 11% CV and 30% qvar.
2. The allowable pressure variation can be set as 10-20% for submain.
3. The main line design depends on the energy situation and the field slope. There is no allowable pressure drop in the mainline. One criterion is the allowable mean velocity which is 5 feet per second for PVC pipes.

To calculate the uniformity of a design you can type ceddis after extracting the programs. The introductory page below has limits of design and will not calculate the uniformity if the emitter spacing is small ie. 1 ft and the length large > 300ft.