Bedform growth and migration caused rapid bed-elevation fluctuations (Dinehart, 1992a) that often were recorded during storm-flow recession ( fig. 16 ). Changes in the stage-discharge relation could be documented from a sequence of discharge measurements, but the causes (changing cross-sectional area or bed roughness) usually were not known. Corrections to the existing relation ("shifts") were distributed uniformly by time or stage. Without detailed information about bed configurations, shifts could not be limited to the actual period when additional roughness affected the stage-discharge relation.
