Terminology – elevated open channel on trestles A water channel constructed above ground level and supported on bents or trestles is generally called what?
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AFlume
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BCanal
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CAqueduct
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DTunnel
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EAll the above
Answer
Correct Answer: Flume
Explanation
Introduction / Context:In hydraulic conveyance, different structures are used to traverse varied terrain. When an open-channel section must be carried above the ground on a lightweight support system, a specific term is used for that arrangement.
Given Data / Assumptions:
- Open-channel flow conditions (free surface).
- Support on bents/trestles rather than massive bridge piers.
- Typical materials include timber, steel, or light reinforced concrete.
Concept / Approach:A flume is an above-ground trough or channel, commonly rectangular or trapezoidal, supported on trestles. It carries water across uneven ground without the mass of a full aqueduct. An aqueduct is a broader term often denoting a larger, bridge-like structure carrying a canal or pipeline across a valley. A canal is generally ground-supported, and a tunnel is a closed, underground conduit.
Step-by-Step Solution:Match the definition: open channel on trestles → flume.Other terms describe different structural contexts.
Verification / Alternative check:Historic irrigation and mining conveyances used timber flumes extensively; modern flow-measurement devices (e.g., Parshall flumes) echo the term for constrained open-channel sections.
Why Other Options Are Wrong:
- Canal: typically at or below grade.
- Aqueduct: larger bridge-like carrier, not a lightweight trestle-supported trough.
- Tunnel: underground enclosed passage.
- 'All the above' mixes mutually exclusive terms.
Common Pitfalls:Using 'aqueduct' for any elevated waterway; in exam terminology, 'flume' is the precise term for the trestle-supported open channel.
Final Answer:Flume