为合理评价滴灌工程在运行过程中堵塞滴头对灌水均匀度及作物生长的影响,以克里斯琴森均匀系数为基础,建立了堵塞滴头位置分布均匀性的概念和计算方法,提出了以堵塞滴头位置分布均匀系数和滴头流量均匀系数的算术平均值为指标的灌水均匀度计算方法,并分别对比分析了毛管和灌水小区两个尺度的灌水均匀度计算结果。结果表明:与克里斯琴森均匀系数相同,考虑滴头堵塞位置分布的灌水均匀系数可以合理反映堵塞滴头数量和滴头堵塞程度对灌水均匀度的影响;同时,该评价指标还可以反映堵塞滴头的位置分布和集中程度对灌水均匀度的影响,有效地解决了克里斯琴森均匀系数仅考虑流量差异而无法正确评价集中堵塞滴头对作物供水及生长影响的问题。
Irrigation uniformity is one of the most important indicators of drip irrigation system,and clogging is perhaps the most common factor which affects the uniformity. In order to evaluate the influence of clogged emitters on the irrigation uniformity and the growth of crops during the operational process of drip irrigation system,the concept and computational method of location distribution uniformity of clogged emitters were set up based on the Christiansen uniformity,and then a new computational method of drip irrigation uniformity was proposed by using the arithmetic mean of the location distribution uniformity of clogged emitters and the flux uniformity of emitters,finally a comparison between several types of computational method of uniformity in a lateral and a subunit was made. The results showed that both the drip irrigation uniformity which considered the location distribution of clogged emitters and the Christiansen uniformity can reflect the influence of the amount of clogged emitter and the level of clogging on irrigation uniformity. In the meanwhile,the proposed method can also reflect the influence of location distribution of clogged emitters on the irrigation uniformity and overcome the weakness of Christiansen uniformity which only considered the influence of flow deviation.