Using an anti-clogging relative index (CRI) to assess emitters rapidly for drip irrigation systems with multiple low-quality water sources

Abstract

Drip irrigation is considered as one of the most suitable methods to utilize multiple low-quality water sources. However, the emitter clogging issue caused has become the main constraint for its application and promotion, which possibly leads to system failure if it becomes uncontrollably acute. How to select the anti-clogging emitter product precisely, in order to improve the system functionality and extend the service life, is the premise of increasing the sustainability of drip irrigation systems broadly used for agriculture and landscape irrigation. Therefore, drip irrigation emitter clogging experiments using three types of low-quality water sources (including water with high sediment and salinity loads and their mixture with the same volume ratio) were conducted. Under the fourteen working conditions included in the present study, the discharge variation rate (Dra), Christiansen coefficient of uniformity (CU) and emitter clogging substances (ECS) of the referenced emitter all showed linear correlations with the other eight types of emitters used in this paper, and the regression slopes were referred to as the anti-clogging relative index (CRI). The relative magnitudes of CRI_Dra, CRI_CU and CRI_ECS could effectively represent the anti-clogging abilities of different emitters. Instead of being affected by the different working conditions or water quality parameters, the differences in CRI were mainly due to the emitter structural characteristics. Two dimensionless parameters of emitter flow paths (W/D and A1/2/L) were significantly correlated to the relative magnitudes of CRI, and thus these two parameters directly allowed for assessing of the anti-clogging ability of emitters. The model established could provide an accurate method for the selection of anti-clogging drip emitter products in a rapid way, which is beneficial for the safe, high-efficiency and long-time running of the drip irrigation system using low-quality water sources.