A canal which is used for irrigation all year round is called-
Perennial canal
Understanding Canals for Year-Round Irrigation
Canals are essential waterways constructed to transport water, primarily for irrigation, navigation, and sometimes hydropower generation. The usage pattern of a canal throughout the year determines its classification. A canal designed to supply water for irrigation consistently, throughout all seasons of the year, relies on a reliable water source that provides flow continuously.
Defining the Correct Canal Type
Let's examine the options provided to determine which type of canal is specifically used for irrigation throughout the year:
- Ditch canal: This often refers to a smaller, open channel, typically used for drainage or localized water distribution within a field or small area. They may or may not operate year-round, depending on the water source and need.
- Continuous canal: While this term suggests uninterrupted flow, it is not the standard technical term used in irrigation engineering to describe a canal operating year-round for irrigation purposes. The term 'continuous' can also refer to the method of water delivery rather than the duration of operation throughout the year.
- Perennial canal: The word 'perennial' means lasting or existing throughout the year. Therefore, a perennial canal is one that is fed by a permanent source of water (like a glacier-fed river or a large reservoir) and is designed to provide irrigation water consistently throughout all seasons, regardless of variations in rainfall.
- Seasonal canal: As the name suggests, a seasonal canal operates only during specific seasons, typically when water is abundant (like the monsoon season) or when certain crops require water. These canals remain dry during the off-season.
Based on these definitions, the canal used for irrigation all year round is correctly identified as a Perennial canal because it ensures water supply throughout the year, supporting continuous farming activities.
Comparison of Canal Types for Irrigation
| Canal Type | Operation Period | Typical Water Source | Irrigation Capability |
|---|---|---|---|
| Perennial Canal | All year round | Permanent sources (rivers from glaciers, large reservoirs) | Supports year-round irrigation and multiple cropping |
| Seasonal Canal | Specific seasons | Rain-fed rivers, smaller reservoirs dependent on rainfall | Supports irrigation only during wet seasons or specific crop cycles |
| Ditch Canal | Variable (often localized) | Various sources, often secondary distribution | Localized irrigation or drainage, scale is typically small |
| Continuous Canal | Not a standard classification based on duration | N/A | Term often relates to water delivery method rather than annual operation |
Therefore, the canal type that provides irrigation water throughout the entire year is the Perennial canal.
Revision Table: Key Canal Concepts
| Term | Definition |
|---|---|
| Irrigation Canal | An artificial channel built to convey water from a source to agricultural fields for watering crops. |
| Perennial Flow | Water flow that occurs continuously throughout the year. |
| Seasonal Flow | Water flow that occurs only during certain parts of the year, dependent on rainfall or snowmelt. |
Additional Information on Perennial and Seasonal Canals
Perennial canals are crucial for intensive agriculture, allowing farmers to cultivate multiple crops in a year (multi-cropping) or grow crops that require water even during dry periods. Their reliable water supply helps in stabilizing agricultural production and reducing dependence on erratic rainfall.
Seasonal canals, while not providing year-round supply, are still vital in regions where rainfall is concentrated in specific periods. They support agriculture during the wet season and are often less expensive to construct than perennial systems which require more complex headworks and larger water sources.
The choice between building a perennial or seasonal canal depends largely on the availability of a reliable water source and the irrigation needs of the command area throughout the year.
Important Questions from Design of Canals
Weed growth in a canal invariably leads to-
As per the recommendation of Bureau of Indian Standard, The shape of the lined canal is
Which of the following is a semi-modular canal outlet?
Among the classification of canals based on alignment criteria, identify the canal in which the number of cross drainage works is maximum?
A fall is constructed to:
