Development of Computer Model for Specification of Irrigation Service: A Case Study of Irrigation System in Northern Vietnam

Irrigation service defines the responsibilities and rights of irrigation system management agencies, water users, and other parties involved in the irrigation service contract. As a result, the irrigation service must be clearly specified and updated by crop seasons and by all partners. Given the inherent complexity of the service, this article presents and discusses the development and application of a computer model designed to support the specification of public service levels in rice-based irrigation systems. Applied to the Tu Mai irrigation system, the model has enabled all involved parties to define irrigation service levels through systematic analysis and a thorough consideration of constraints such as water resource characteristics, hydraulic structures, and the operational plans of the irrigation system. The research findings have also helped relevant agencies reach agreements on irrigation service levels for the particular irrigation season of spring 2023, which included one irrigation period for land preparation and five subsequent irrigation periods for rice crops corresponding with a specific schedule for operating the system (discharges and duration) that met the farmers’ requests for their farming practices and reduced the loss due to rice crop yield decline at the irrigation system as a whole. Additionally, recommendations for improving irrigation services in the Tu Mai system have been made, including upgrading the head pumping station to accommodate lower water levels in the Cau River, aligning the irrigation schedules of the Water User Associations (WUAs) more flexibly, and strictly supervising water deliveries to ensure safety and fairness.