Comparison of Various Models for Optimal Water Distribution in Canal Systems

Optimized water distribution models for canals are used to ensure that crop water demands are met through the efficient allocation of flow rates and times. A well-designed water distribution model can shorten irrigation durations, reduce canal water delivery losses, and improve irrigation water utilization efficiency. In this study, five optimal water distribution models were selected for comparison: Irrigation Model 1 (upstream-to-downstream irrigation), Irrigation Model 2 (downstream-to-upstream irrigation), Irrigation Model 3 (continuous irrigation between groups, with rotational irrigation within groups), Irrigation Model 4 (rotational irrigation between groups, with continuous irrigation within groups), and Irrigation Model 5 (rotational irrigation-based optimal distribution). These models were applied to the Fengqigou branch canal in the Bojili Irrigation District. The advantages and disadvantages of each model were analyzed from five perspectives: total water distribution duration; utilization of canal infrastructure; leakage losses in canal delivery; volume of abandoned water; and operability for irrigation managers. The results indicated that Irrigation Models 1 and 2 are easy to manage, and result in minimal leakage losses for upper-level canals. Irrigation Models 3 and 4 exhibit shorter total irrigation durations and lower water abandonment rates. However, Irrigation Model 5 requires optimization of idle times to enhance its applicability.