New Stage-Discharge Equation for the SMBF Flume

Flumes for indirect discharge measurements are widespread and are characterized by a particular shape of the cross section area with various degrees of convergence and subsequent divergence. The flume named Samani, Magallanez, Baiamonte, Ferro (SMBF) is a simple and inexpensive instrument and its channel contraction is obtained by applying two semicylinders to the walls of a rectangular cross section. At first, in this paper a new stage-discharge equation for the SMBF flume is theoretically deduced. Then, this equation is experimentally calibrated using the laboratory measurements from the literature for different values of the contraction ratio. Finally the field measurements carried out at Sparacia experimental area (Sicily, South Italy) by a SMBF flume inserted into a horizontal flume and characterized by a contraction ratio equal to 0.5, are used for testing both the new stage-discharge relationship and the one originally proposed in the literature. (C) 2016 American Society of Civil Engineers.