Hydraulic Geometry Relations for Stable Channel Design

This study compared the downstream hydraulic geometry relations for stable channel design derived by other investigators with the equations derived from the data gathered from Iranian rivers based on the at-a-station method. For these rivers measurements of 425 velocity profiles and nearly 6,000 point velocities for 85 cross sections were employed to accurately determine flow discharge at a specified river section. For at-a-station method, grain size and the Shields parameter were not important for the determination of width and depth of a stable channel. It was found that the dominant or at-a-station discharge did not affect the discharge exponent in the depth equation, but it affected the discharge exponent in the width equation. Furthermore, discharge was not the controlling variable for the prediction of slope of stable channels, but grain size and the Shields parameter were.