在设计滴灌系统时,要首先选择设计滴头均匀系数EU_d。而EU_d实际上是一项经济指标。EU_d高就要求允许压力偏差ΔH_t要小,一般也要求投资与管理费高。EU_d低就要求灌水量较大。作物间的配水也就差。由于这种矛盾的趋势,所以存在着投资和运行费用最小的最优EU_d。本文作者在美国加 In the design of drip irrigation system, we must first choose to design drip uniformity coefficient EU_d. EU_d is actually an economic indicator. EU_d high required to allow the pressure deviation ΔH_t to be small, generally require high investment and management fees. EU_d low requires a large amount of irrigation. The distribution of water between crops also worse. Due to this contradictory trend, there is an optimal EU_d with minimal investment and operating costs. The author of this article is added in the United States