Difficulty: Easy
Correct Answer: All of the above
Explanation:
Introduction / Context:
Sustainable irrigation requires not only conveyance of water but also safe removal of excess. Hence, canal (supply) and drainage (disposal) systems must be planned together to avoid waterlogging and salinity, and to maintain infrastructure integrity.
Given Data / Assumptions:
Concept / Approach:
Canal systems commonly take ridge alignments to maximize command by gravity; water is then distributed via minors and watercourses. Drainage systems occupy the thalwegs (lowest lines) to collect surface and subsurface flows and discharge to natural streams. Proper integration makes the two systems complementary.
Step-by-Step Solution:
Verification / Alternative check:
Command design guidelines show paired maps for canals and drains; failures to coordinate cause chronic waterlogging.
Why Other Options Are Wrong:
Any single statement alone is incomplete; “None” contradicts well-established planning practice.
Common Pitfalls:
Using canals for dual drainage in flat terrain without checks; underestimating subsurface drainage needs.
Final Answer:
All of the above
Discussion & Comments