Abstract

This paper presents a study on the effects of discharge and sediment load on the bankfull area at Gaocun, a representative hydrometric station in the lower Yellow River. The moving average discharge and the moving average incoming sediment coefficient, which is defined as the ratio of sediment concentration to discharge, were used to reflect the integrated effects of several consecutive years’ flow and sediment load conditions. The analysis indicated that the coefficient of determination between the bankfull area and the 4 years’ moving average discharge of flood season has the highest value, and that between the bankfull area and the 5 years’ moving average incoming sediment coefficient of flood season has the highest value. This revealed an important phenomenon which is the delayed response in the channel form to the incoming flow and sediment load conditions. An equation for the calculation of bankfull area at Gaocun Station was proposed, in which the hysteresis effect in channel response to discharge and sediment load was considered.

Keywords: Yellow River, hysteresis effect; fluvial processes, bankfull area, bankfull discharge