Garnett’s diagrams (graphical aids) are traditionally used to solve the design equations of a canal according to which regime theory?

Introduction / Context:Before widespread digital computation, designers relied on graphical tools to solve iterative canal-design equations. Garnett’s diagrams are classic aids connected with one of the two well-known regime design approaches: Kennedy and Lacey.

Given Data / Assumptions:

• Design target is a non-silting, non-scouring canal section.
• Charts/nomograms attributed to Garnett are referenced.
• Question asks which theory they support.

Concept / Approach:

Kennedy’s theory centers on critical velocities to prevent silting/scour and involves interdependent variables (depth, velocity, slope). Garnett produced graphical charts to streamline these computations, allowing designers to read off solutions for given discharge and silt grade.

Step-by-Step Solution:

Verification / Alternative check:

Many irrigation texts list “Garnett’s diagrams for Kennedy’s design” alongside regime tables.

Why Other Options Are Wrong:

Lacey’s method uses a different set of empirical relations; Gibb’s and Lindley’s are not the standard attributions for Garnett’s charts.

Common Pitfalls:

Conflating graphical tools across theories; overlooking that each regime theory has its own calibration and parameters.

Final Answer:

Kennedy’s theory