Discussion of 'Assessment of Hydraulic Performance of Drip-Irrigation Emitters at Low Head Pressures' by Chao Zhang, Yaohu Kang, Shufang Jiang, Shuqin Wan, and Shiping Liu

摘要

The authors are appreciated for presenting an experimental procedure for testing hydraulic performance of three of the most commonly available high-head in-line drip-tape emitters under different working-head conditions ranging from 0.2 to 10 m, especially for low-head conditions. The present analysis mainly deals with, first, the calculation of the coefficient of manufacturing variation (C_v) and the emitter flow exponent (x) with regard to different phases of water pressures, then the determination of the best choice among the pressure ranges examined for three types of low-head drip emitters tested. Resulting from the experiments, the findings for the variations of the values of discharge, coefficient of manufacturing variation, and the emitter flow exponent, with different ranges of working pressures, are presented in the paper in Figs. 2, 3, and 4, respectively. In line with this concept, this work may provide a useful decision support tool for achieving a good design solution among alternatives with high water application uniformity, and the resulting high irrigation efficiency.