Hydraulic modelling of irrigation canals for improved flow conditions in surface irrigation systems

Surface irrigation is a widely utilized method for agricultural irrigation, but it often suffers from low conveyance efficiency. Improving flow conditions in surface irrigation systems is crucial for enhancing water distribution and optimizing crop production. This study presents a comprehensive hydraulic modelling approach aimed at improving flow conditions in irrigation canals. The analysis focuses on the Doho Rice Irrigation Scheme in Uganda and utilizes the HEC-RAS hydraulic model. Different canal conditions, including desilting and vegetation clearing, concrete lining, plastic lining, and brick lining, are evaluated for their impact on flow dynamics. The findings reveal that all four canal conditions lead to significant improvements in flow conditions compared to the current state of the canal. Plastic lining emerges as the most effective solution, resulting in a remarkable 48 % improvement in flow conditions. Concrete lining follows closely with a 37 % improvement, while brick lining shows a 39 % enhancement. Desilting and vegetation clearing contribute to a 20 % improvement in flow conditions. These results underscore the potential of hydraulic modelling in guiding the design and management of irrigation canals to ensure sustainable water use practices. © 2023 Indian Society for Hydraulics.