Optimization Design Method of a Large-Scale Multilevel Gravity Drip Irrigation Pipe Network System Based on Atom Search Optimization

A multilevel drip irrigation system generally uses a first-level pivot as the water source. The water is delivered to each head pivot in the field drip irrigation subsystems through the main water distribution pipe network system (MWDPNS). Subsequently, it is irrigated to farmland through field drip irrigation pipe network subsystems (FDIPNS). This paper focused on the lowest total investment of the pipe network to establish a model for simultaneous optimization of the pipe network layout and pipe diameter selection in a multilevel gravity drip irrigation system, and the method and steps based on atom search optimization are proposed. First, all the FDIPNS are optimized; then, the MWDPNS is optimized with the optimization results of each subsystem as the basic design parameters. For the MWDPNS, the available water diversion nodes other than the water demand nodes can be added and selected. By comprehensively considering the topological and hydraulic constraints, the topology design and pipe diameter selection are optimized simultaneously when the selection of the water distribution nodes is uncertain. For the FDIPNS, the field width is regarded as a linear piecewise function of the field length, and the constraints such as the pipeline layout, flow velocity, discharge, pressure, and rotational irrigation scheme are considered. This model can be applied to most irregular fields. Taking a two-level gravity drip irrigation project in Xinjiang, China as an example, the effectiveness of the proposed model and algorithm was assessed. The results demonstrate that the proposed optimization method has a good application value for the pipe network design of multilevel gravity drip irrigation systems.