Impermanent changes investigation of shape factors of the volumetric balance model for water development in surface irrigation

One of the most methods for design of surface irrigation is volume balance model. This model assumed that the shape factors are constant. This assumption causes significant errors in computations. In this paper were investigated the variations of the shape factors relative to time by Valiantzas’ method. This method is based on combination of volume balance and kinematic wave models. Results of the method as advance curve had a good agreement...