Canal system hierarchy: Choose the correct sequence of components in a typical canal irrigation system, from headworks to the smallest conveyance.

Introduction / Context:
Irrigation networks distribute water from a river diversion or storage to fields through a hierarchical system that progressively branches into smaller channels.

Given Data / Assumptions:

• Standard nomenclature: headworks, main canal, branch canal, distributary, minor (watercourse later beyond minor).
• Gravity distribution from larger to smaller channels.

Concept / Approach:
The main canal originates at the headworks. It feeds branch canals, which in turn feed distributaries. Distributaries feed minors (and then watercourses to fields).

Step-by-Step Solution:
Start: Head works.Primary conveyance: Main canal.Secondary: Branch canal.Tertiary: Distributary.Quaternary: Minor.

Verification / Alternative check:
Project drawings of major canal systems confirm this descending order of command and capacities.

Why Other Options Are Wrong:

• Options a, c, d, e misorder one or more elements (e.g., placing branch before main).

Common Pitfalls:
Confusing “distributary” with “minor”; mixing watercourse with minor.

Final Answer:
Head works – main canal – branch canal – distributary – minor