REVISING THE CUTTHROAT FLUME SETTLEMENT RATING ADJUSTMENT PROCEDURE

A study was conducted to revise the procedure for adjusting discharge measurements in a cutthroat flume subjected to settlement in free-flowing conditions. A series of 57 tests was performed on six different size cutthroat flumes. Each flume was systematically adjusted to simulate settlement in both the lateral and the longitudinal directions. Discharge inaccuracies were then recorded for each settlement condition. The test results were combined with the results of three cutthroat flumes previously reported. The coefficients describing the flume geometry. Cd(lat) and C d(long), were determined to be significantly different than previously indicated. New expressions for C d(lat) and C d(long) were formulated for inclusion into the previously reported discharge measurement adjustment procedure.