Channel Geometry Relationships

At a gauging station, single channel cross-section is often monitored across a variety of flows to establish a stage-discharge curve. The stability of the channel will determine how frequently such stage-discharge relations are updated. Data from USGS Form 9-207 reports provide discharge values and associated channel Bankfull area, width, and velocity measurements. Channel mean depth is computed by taking the quotient of cross-sectional area and width. Geometrical relationships between channel discharge and channel cross-sectional area, width, and depth are used to understand the channel geometry at the Bankfull Discharge value, as well as channel constrictions and behavior at other discharge values.