Assessment of Estimated Design Discharge with Physical Need Based Installed Drip Irrigation Systems in 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, plugging  were compared with physical need based CROPWAT software estimation were evaluated. The emitters discharge was collected at the beginning, 1/3 down, 2/3 down and end of each selected lateral by volumetric method. The soil texture and infiltration data was also determined for the efficiency and adequacy of drip irrigation system. The head loss along the laterals was determined for uniformity of the drip irrigation system. These collected values were averaged for each plot and water requirement was determined by using CROPWAT computer software. Results of the study revealed that the head loss in Malakand Agency (0.6 m) irrigation systems remained uniform while these are varying in Nowshera and Charsadda (0.4-1.5 m). Theoretical discharges are mostly less than actual discharges with a maximum of 55 % increase in Malakand Agency and a minimum at Charsadda with 3.3 % increase in actual discharge. Due to increased laterals length with more emitters per lateral gives fluctuation in discharge and pressure. Discharge variation was more due to low-pressure head in Nowshera.

Keywords: Coefficient of variation, Design, Plugging, Head Loss, Theoretical Discharge