Ecology, Environment and Conservation Paper

DRIP TUBE DISCHARGE SENSITIVITY TO WATER TEMPERATURE

AboutaLeb Hezarjaribi, Asaad Abdelkader Abdalla, Mousa Hesam, Abdolreza Zahiri and Ghorban Ghorbani nasrabad

Abstract

The water viscosity changes due to changing water temperature, and causes emitter discharge variations if the flow through the emitter is laminar. The efficiency of drip irrigation system depends directly on the uniformity of water discharged from the emitters throughout the system. The objective of this study was laboratory studying of three different types of emitters (two inline emitters of Siplast and Inline-168, and one online emitter of Katif-8) to investigate the effect of different water temperatures of 14, 22, 32, 42deg.C on water temperature at 50, 100, and 150 kPa. Although Siplast and Inline-168 were classified NPC emitters and in spit of increasing water temperature from 12 to 42deg.C, but slid increase of theirs discharge with temperature exhibited that their sensitivity to water temperature are not significant. In case of Katif-8, not only variation in water temperature but also generally variation in operation pressure could not vary emitter discharge (classified as a PC emitter). High coefficient of determination and mainly as quadratic relation were found between TDR and water temperature. Although most TDR-water temperature data have been shown to be linear, but in this study both linear and quadratic functions were found with high coefficient of determination. Also laboratory observation showed extension of drip tube length as water temperature increased.