Assessment of Coefficient of Variation of Emitters Flow Rate with Respect to Design, Manufacturer and Plugging in Installed Drip Irrigation Systems at Selected Sites of Peshawar Valley

Abstract

The study was conducted to assess the performance of drip irrigation systems installed at Charsadda, Malakand Agency and Nowshera. The performance parameters of the drip irrigation system included the coefficient of variation of emitters flow rate with respect to design of manufacturer, hydraulics, grouping of the emitters, plugging, uniformity, efficiency, adequacy and estimated design discharge , measured Cv(H) values for all plots are less than 30%.  Hydraulic design seems to be only one of the minor factors in the evaluation of overall uniformity of a micro-irrigation system. Having the Cv(HM) variations are only about 0-7% except plot No.1 of Nowshera farm that is 24.16%, expressed by Cv. micro-irrigation system can be designed hydraulically to maintain emitter flow uniformity within 10% or 20% emitter flow variations. Grouping variation of emitters flow is 0-4% in Charsadda and Malakand Agency farm. In plot No.1 of Nowshera farm its 20.60% while in plot No.2 and 3 it is 0%. The group coefficient is affected by emitters flow rate that is uniform. In Charsadda and Malakand Agency farm the overall effect of hydraulic, manufacturer and grouping are 0-7.11% and 0-1.02% in plot No.3 and 2 of Nowshera farm, in plot No.1 it is 31.75%. Among all the factors affecting the uniformity, plugging is the most significant factor. The Cv(P) is 0% resulted from partial plugging. 5-10% plugging could produce Cv(P) of 23-33%. This system has no plugging, which implies that the system is performing excellent. Cv(HMP) was evidently affected most by hydraulic and manufacture variation. The overall Cv(HMP) is maximum in Charsadda plot No.2 is 16.1%  while in plot No.3 and 4 this range from 1.8 to 0.6%. In Malakand and Nowshera farm this overall variation give negative values due to more variation in the level of plugging and CV(HM). .

Keywords: Coefficient of Variation, Emitters, Plugging, Uniformity, Drip Irrigation