## 4 Discussion  
In regions with limited irrigation water resources, irrigation projects commonly implement a system in which the main pipelines are supplied continuously with water, while the branch pipelines operate under a rotational supply system. This approach aims to reduce project costs, optimize equipment utilization, and expand the irrigated area [35, 36]. For large-scale irrigation systems, the typical operational mode during the irrigation season involves continuous water supply to the main pipelines and rotational water supply to the branch pipelines. This water supply configuration is also the dominant approach used in large-scale drip irrigation projects in Xinjiang, China [37, 38]. The water supply mode significantly affects the hydraulic reliability of the pipeline network. Research has shown that the traditional rotational irrigation method for branch pipes, commonly employed in design, is not fully suitable for large-scale pipeline networks. In the segmented water supply mode, based on the rotational irrigation system, the designed flow rates for branch pipes are excessively high, resulting in negative pressure head in various sections of the pipeline network during operation. This is a primary cause of frequent pipe bursts during the initial operation phase of the local pipeline network. Upon transitioning to a uniform water supply mode, the flow rates to the branch pipes were reduced. Although this adjustment enables the pipeline network to fulfill its water distribution function, only a limited number of branch pipes achieve the required minimum inlet head (\(H_{min}\)), and pressure head fluctuations between adjacent branch pipes increase. Furthermore, the flow rate generally exceeds the economic flow velocity, and the total flow in the pipeline network fails to meet the design specifications, leading to increased flow deviation between branch pipes. As a result, the reliability of the pipeline network is compromised. To ensure proper field irrigation performance, it is often necessary to install pressure head or flow regulation equipment downstream of the control valves in the field irrigation system. Additionally, when planning rotational irrigation groupings, not only the number of rotational irrigation groups but also the positioning of open branch pipes within the pipeline network should be considered to optimize the rotational irrigation scheme. It is also recommended to install automatic intake and exhaust valves, along with other control devices, at the inlets of the branch pipes [39]. With the development of large-scale agriculture, the scale and complexity of irrigation pipeline networks have significantly increased. Failure to optimize the water supply mode in a timely manner can render the original rotational irrigation system ineffective, negatively impacting the water supply efficiency of the pipeline network [40; 41]. To maximize project benefits, a pressure head reduction and uniform water supply mode has been adopted. Research indicates that, compared to the segmented water supply mode, the uniform water supply mode, based on the continuous irrigation system, significantly reduces pressure head fluctuations in the pipeline network. Additionally, the flow velocity in the branch pipes approaches the economic flow velocity, which reduces the flow deviation rate and enhances the hydraulic reliability of the network. However, the pressure head at the inlet of most branch pipes still fails to reach the required minimum node head (\(H_{min}\)). To further improve the safety and reliability of the water supply, effective monitoring and timely adjustment of the water supply flow are recommended. With the diversification of local cropping patterns, there has been an emerging demand for a certain degree of random water supply to meet the water requirements of various sectors [42; 43], which has led to increased complexity in system scheduling.