Variation of Regime Coefficients in Pakistan Canals

The three degrees-of-freedom in a straight alluvial canal can be represented by Froude number F; width-depth ratios, and energy gradient S. They also can be represented by the coefficients in regime equations. The physical interpretation of these regime coefficients is investigated and thus the basic structure of Lacey's regime equations is explained. The Canal and Headworks Data Observation Program (CHOP) data on Pakistan Canals are analyzed in the framework of regime theory and it is shown that: (1) the width of a stable channel section is related to the maximum operational discharge with α₃ α₃ = 2.87; and (2) the regime coefficients, α₁ and α₄, are related as the bed material load and resistance functions of sand-bed channels. It is concluded that in their day to day operation, the sand-bed alluvial canals have only one degree-of-freedom that is related to their bed material load.