Evaluation of various design models of irrigation sedimentation basins

Abstract

Sedimentation basins are structures that separate suspended sediments from river flows at irrigation intakes. There are many ways to design these sedimentation basins, some of which lead to unrealistic results because of their simplifying assumptions. Some of these methods are complex and are extremely difficult to use. Meanwhile, other methods to reduce the above problems have been proposed by a number of researchers that are based on laboratory or analytical studies. Due to the existence of various models, it is difficult to determine which approach is the most appropriate model. Here, by introducing multiple methods, their performance has been evaluated by comparison with laboratory data. Experiments were conducted on a flume 12 m in length, 1.2 m in width, and 0.5 m in height for three sediment sizes and for different discharges. Trapping efficiencies were calculated based on the remaining sediment in the invert of the flume after completion of the experiment. The results showed that the United States bureau of reclamation model shows a high efficiency of the sedimentation basins. In addition, it was found that the efficiency estimates of this model are very sensitive to input parameters. Examination of various statistical characteristics showed that the trapping efficiency in this study is consistent with the Sarikaya and Einstein models. Also, a regression equation with an accuracy of RMS = 7.32 can be used to estimate the trapping efficiency in irrigation sediment basins.