Field Investigations of Hydraulic Jumps in Natural Channels with Discrepancy Corrections for Experimental-based Formulations

The phenomenon of hydraulic jumps has been widely studied in laboratory flumes. However, few studies have been made to bridge the discrepancy encountered in the formulation of relations ascribing hydraulic jumps based on laboratory model studies and that occur in natural conditions. Most of the predictive formulae for sequent depth ratio and length of jump proposed in the literature have not been verified in the field. The present study attempts to link the field investigation data of hydraulic jump in a weir with laboratory channel flume observation for similar flow conditions. The hydra­ulic jump parameters were collected in the field using feasible technologies in the study weir. The weir selected for this study has geometric, kinematic and Froude similarities with the laboratory model. The comparison of laboratory model data and field measurements showed inconsistency. It is observed that the sequent depth ratio and length of the jump are inaccurately predicted by the laboratory relation compared to the field observations by the laboratory relation. A field-validated-based relationship is suggested for the calculation of sequent depth and length of jump in a smooth rectangular channel for Froude numbers ranging from 4 to 10.