The Impact of Different Design Approaches on Fine Sediment Transport in Gezira Scheme, Sudan

Abstract

AbstractThis study aims to understand the mechanism of cohesive sediment transport in irrigation canals when adopting different design approaches. This was achieved through developing a mathematical model to design unlined irrigation canals using three design approaches: regime theory, tractive force and maximum permissible velocity. The latter was modified by the authors to overcome some of its limitations. The model, named ICDesign, was developed using C Sharp language to design the irrigation canals and generate cross sections and a longitudinal profile. Then it was applied to design Zananda Major Canal in the Gezira scheme, Sudan, as a case study. HEC-RAS model was used to simulate the sediment transport based on different design approaches. It was found that the design obtained from the modified maximum permissible velocity gives the least amount and distribution of sediment accumulation along the canal. Thus, it was concluded that the developed software can be used in the design of a variety of irrigation canals. The extent of the applicability and use of the software shall be determined in the future studies.KeywordsIrrigation canalsGezira schemeSediment depositionHEC-RASMaximum permissible velocityTractive force