The working regime of a sprinkler irrigation system includes the duration of sprinkling at each operating point, the number of operating positions a sprinkler can cover per day, the number of sprinklers operating simultaneously at any given time, and the rotation irrigation schedule. The formulation of the sprinkler irrigation working regime requires calculating parameters such as the sprinkling time at each operating point, the number of operating points a sprinkler can cover daily, and the number of sprinklers that need to operate simultaneously, based on the working parameter formulas of the sprinkler irrigation equipment. The grouping for rotation irrigation is determined according to the number of simultaneously operating sprinklers and the layout of sprinkler points. The following principles should generally be followed when organizing rotation irrigation groups:
1.The number of sprinklers or flow rate in each rotation group should be as consistent as possible, with the number of simultaneously operating sprinklers typically varying by no more than 1–3. This ensures stable pump flow and maintains operation within the high-efficiency range. The number of simultaneously operating sprinklers in a rotation group should ideally be an integer multiple of the number of sprinklers on a single lateral.
2.When multiple laterals operate simultaneously on a single mainline, water flow should be appropriately distributed to reduce the mainline flow rate and head loss. Attention should also be paid to maintaining flow balance in the upstream pipeline network.
3.The division of rotation groups must consider ease of management and operation, striving for simplicity and regularity. To facilitate operational management, key parameters such as the number of simultaneously operating sprinklers, laterals, control point working pressure, and allowable variation ranges should be provided under normal conditions. Alternatively, rotation groups may be presented in a tabulated format for easier operational management.
4.The principle of rotation groups can also be applied to sprinkler irrigation systems with movable pipelines.
