Irrigation and Water Distribution Scheduling Model for Irrigation Districts Considering Multiple Factors

Abstract

In irrigation districts, water distribution satisfaction directly affects service quality. This study constructed an irrigation scheduling model that considers both demand-driven and supply-driven modes, along with supply uncertainty, irrigation method diversity, response time, and water level effects. Applied to a large Chinese irrigation district, the model successfully allocated water to 45 channels under fixed supply, with upstream channels achieving maximum flow diversion and downstream Channel 10 requiring a 4.7-h response time. Under variable supply (40, 30, and 50    m 3 / s ), the model dynamically adjusted flows, with Canal 21 requiring three separate irrigation sessions. The rotational grouping module divided 17 tertiary channels into 3 groups, achieving end-time differences of only 0.48, 1.14, and 0.92 h, reducing management workload. Under demand-driven conditions, the model prioritized flow-rate satisfaction, delivering 102.6    m 3 / s against a main canal capacity of 60    m 3 / s , meeting all flow demands while downstream irrigation time demands remained unmet due to supply constraints. This study provides a practical modeling framework for improving water-use efficiency and reducing scheduling conflicts in large-scale irrigation systems.