Canal system hierarchy: Choose the correct sequence of components in a typical canal irrigation system, from headworks to the smallest conveyance.
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AHead work – distributary – branch canal – minor
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BHead works – main canal – branch canal – distributary – minor
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CHead works – main canal – branch canal – minor – distributary
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DHead works – branch canal – main canal – distributary – minor
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EHead works – main canal – minor – distributary – branch canal
Answer
Correct Answer: Head works – main canal – branch canal – distributary – minor
Explanation
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