Question

In the context of cross-drainage structures, the correct statement(s) regarding the relative positions of a natural drain (stream/river) and an irrigation canal, is/are

• A. In an aqueduct, natural drain water goes under the irrigation canal, whereas in a super-passage, natural drain water goes over the irrigation canal.
• B. In a level crossing, natural drain water goes through the irrigation canal.
• C. In an aqueduct, natural drain water goes over the irrigation canal, whereas in a super-passage, natural drain water goes under the irrigation canal.
• D. In a canal syphon, natural drain water goes through the irrigation canal.

Hint:

In cross-drainage structures, the relative position of the canal and natural drain determines the type of structure to be used. Aqueducts, super-passages, and level crossings each have specific flow arrangements.

Answer 1

The Correct Option is A, B

In cross-drainage structures, different arrangements are used depending on the relative positions of the natural drain (river/stream) and the irrigation canal. The options describe different scenarios for how the two systems interact.

Step 1: Understand aqueduct and super-passage.
- In an aqueduct, the natural drain water typically goes under the irrigation canal to avoid interference. - In a super-passage, the natural drain water typically goes over the irrigation canal to maintain the natural flow of the stream without obstruction.

Step 2: Understand level crossing and canal syphon.
- In a level crossing, the natural drain water flows through the irrigation canal, often when the water bodies are at the same level. - In a canal syphon, the water flows through the irrigation canal, typically used when the canal crosses a natural drain below the ground.

Step 3: Analyze the options.
- (A) is correct because in an aqueduct the natural drain water goes under, and in a super-passage, it goes over. - (B) is correct because in a level crossing, the natural drain water flows through the canal. - (C) is incorrect as it reverses the description for aqueducts and super-passages. - (D) is also incorrect, as in a canal syphon, the natural drain water flows through the canal but it is used for a different kind of crossing.

Final Answer: (A) In an aqueduct, natural drain water goes under the irrigation canal, whereas in a super-passage, natural drain water goes over the irrigation canal.
(B) In a level crossing, natural drain water goes through the irrigation canal.