1. Concept Explanation (Exam-Focused)
Canal irrigation is a system in which water is diverted from rivers or reservoirs and supplied to fields through canals.
It is widely used in:
North India
Delta regions
Large command areas
A. Types of Canals
1. Based on Source
(i) Perennial Canals
Water available throughout the year.
Fed by dams/reservoirs.
Example: Ganga Canal
(ii) Non-Perennial Canals
Water available only during rainy season.
Fed by rivers without storage.
2. Based on Alignment
(i) Ridge Canal
Runs along watershed line.
Supplies water on both sides.
(ii) Contour Canal
Runs parallel to contours.
(iii) Side Slope Canal
Runs along valley side slope.
3. Based on Purpose
• Irrigation canal
• Power canal
• Feeder canal
• Navigation canal
B. Canal Lining
Canal lining means covering the bed and sides of canal with impervious material.
Materials Used:
Cement concrete
Brick
Stone
Asphalt
Plastic lining
Advantages of Lining:
• Reduces seepage losses
• Increases carrying capacity
• Prevents water logging
• Reduces weed growth
• Saves land width
Disadvantages:
• High initial cost
• Difficult repairs
• Cracking problem
C. Canal Losses
Types of Canal Losses
1. Evaporation Loss
Loss due to surface evaporation.
2. Seepage Loss (Most Important)
Loss due to percolation into soil.
3. Absorption Loss
Water absorbed by dry soil initially.
4. Transpiration Loss
Loss due to vegetation along banks.
2. Important Formulas
Seepage Loss
Loss=Wetted Area×Seepage rateLoss = Wetted\ Area \times Seepage\ rateLoss=Wetted Area×Seepage rate
Conveyance Efficiency
ηc=Water at outletWater at head×100\eta_c = \frac{Water\ at\ outlet}{Water\ at\ head} \times 100ηc=Water at headWater at outlet×100
🔥 Repeated in exams
3. Short Notes / One-Liners
• Seepage loss is maximum in unlined canals.
• Lining increases velocity of flow.
• Ridge canal is best for uniform distribution.
• Contour canal is cheapest.
• Lined canals reduce water logging.
• Most economical lining: Concrete.
• Maximum loss in canals: Seepage.
4. PYQ Patterns
Frequently Asked:
Difference between perennial & non-perennial
Advantages of lining
Ridge vs contour canal
Types of canal losses
Typical Traps:
• Confusing absorption & seepage
• Assuming evaporation is major loss
• Thinking lining increases seepage (wrong)
5. Solved Examples
Example 1 (Conceptual)
Which loss is maximum in canals?
Seepage loss.
Example 2 (Numerical)
Wetted area = 5000 m²
Seepage rate = 2 mm/hour
Loss=5000×0.002=10 m³/hrLoss = 5000 \times 0.002 = 10 \text{ m³/hr}Loss=5000×0.002=10 m³/hr
6. MCQs (50 Exam-Level)
Q1. A perennial canal gets water from:
A) Rainfall
B) Groundwater
C) Reservoir
D) Lakes
✅ Answer: C
Q2. Ridge canal runs along:
A) Valley
B) Contour
C) Watershed
D) River bed
✅ Answer: C
Q3. Which canal has water only in rainy season?
A) Perennial
B) Ridge
C) Non-perennial
D) Feeder
✅ Answer: C
Q4. Canal lining mainly reduces:
A) Evaporation
B) Seepage
C) Transpiration
D) Absorption
✅ Answer: B
Q5. Cheapest canal is:
A) Ridge canal
B) Contour canal
C) Lined canal
D) Feeder canal
✅ Answer: B
Q6. Maximum loss in canals is:
A) Evaporation
B) Seepage
C) Transpiration
D) Absorption
✅ Answer: B
Q7. Lining of canal results in:
A) Increased seepage
B) Decreased velocity
C) Increased discharge
D) More erosion
✅ Answer: C
Q8. Which is not a canal loss?
A) Seepage
B) Evaporation
C) Condensation
D) Transpiration
✅ Answer: C
Q9. Which canal is best for irrigation efficiency?
A) Non-perennial
B) Unlined
C) Ridge
D) Side slope
✅ Answer: C
Q10. Lining material most commonly used:
A) Plastic
B) Stone
C) Concrete
D) Asphalt
✅ Answer: C
Q11. Water logging occurs mainly due to:
A) Lining
B) Seepage
C) Evaporation
D) Rainfall
✅ Answer: B
Q12. A feeder canal is used to:
A) Supply water to fields
B) Feed another canal
C) Drain water
D) Generate power
✅ Answer: B
Q13. Which loss reduces after first few days of running?
A) Seepage
B) Evaporation
C) Absorption
D) Transpiration
✅ Answer: C
Q14. Lining is not economical when:
A) Water is costly
B) Soil is sandy
C) Canal is temporary
D) Seepage is high
✅ Answer: C
Q15. Main disadvantage of lined canal:
A) More seepage
B) High cost
C) Low velocity
D) More erosion
✅ Answer: B
Q16. Contour canal follows:
A) River path
B) Contour lines
C) Ridge
D) Valley
✅ Answer: B
Q17. Which loss depends on climate?
A) Seepage
B) Evaporation
C) Absorption
D) Percolation
✅ Answer: B
Q18. Lining increases:
A) Wetted perimeter
B) Roughness
C) Hydraulic radius
D) Discharge capacity
✅ Answer: D
Q19. Which canal supplies both sides?
A) Contour
B) Side slope
C) Ridge
D) Feeder
✅ Answer: C
Q20. The main purpose of canal lining is to:
A) Improve aesthetics
B) Reduce seepage
C) Increase rainfall
D) Reduce evaporation
✅ Answer: B
Q21. Seepage loss is highest in:
A) Clay soil
B) Sandy soil
C) Rock soil
D) Black soil
✅ Answer: B
Q22. Which is a non-perennial canal?
A) Ganga canal
B) Yamuna canal
C) Seasonal river canal
D) Indira Gandhi canal
✅ Answer: C
Q23. Transpiration loss is due to:
A) Soil
B) Crops
C) Vegetation
D) Wind
✅ Answer: C
Q24. Canal lining reduces:
A) Discharge
B) Velocity
C) Cross-section
D) Losses
✅ Answer: D
Q25. Most important canal loss for design is:
A) Evaporation
B) Seepage
C) Absorption
D) Transpiration
✅ Answer: B
Q26. A lined canal compared to unlined has:
A) More roughness
B) Less velocity
C) Less seepage
D) More losses
✅ Answer: C
Q27. Which canal is most economical in hilly areas?
A) Ridge
B) Contour
C) Feeder
D) Power canal
✅ Answer: B
Q28. Which is not an advantage of lining?
A) Water saving
B) Increased velocity
C) Reduced land width
D) Reduced discharge
✅ Answer: D
Q29. Absorption loss is maximum when:
A) Canal is old
B) Canal is new
C) Canal is lined
D) Canal is full
✅ Answer: B
Q30. Which loss reduces after soil becomes saturated?
A) Evaporation
B) Seepage
C) Absorption
D) Transpiration
✅ Answer: C
Q31. Which canal is used for hydroelectric plants?
A) Feeder
B) Irrigation
C) Power canal
D) Ridge
✅ Answer: C
Q32. Which is a benefit of ridge canal?
A) Cheap
B) Less land
C) Supplies both sides
D) Less excavation
✅ Answer: C
Q33. Canal lining is most required in:
A) Clay soil
B) Sandy soil
C) Rocky soil
D) Black soil
✅ Answer: B
Q34. Evaporation loss mainly depends on:
A) Soil
B) Canal shape
C) Climate
D) Lining
✅ Answer: C
Q35. Which is true?
A) Lined canals increase water logging
B) Unlined canals reduce seepage
C) Lined canals reduce losses
D) Lining reduces velocity
✅ Answer: C
Q36. Seepage loss leads to:
A) Flooding
B) Water logging
C) Rainfall
D) Drought
✅ Answer: B
Q37. Which canal has highest construction cost?
A) Contour
B) Ridge
C) Lined
D) Unlined
✅ Answer: C
Q38. Which loss cannot be fully eliminated?
A) Seepage
B) Absorption
C) Evaporation
D) Transpiration
✅ Answer: C
Q39. Which canal is safest from breach?
A) Unlined
B) Lined
C) Seasonal
D) Feeder
✅ Answer: B
Q40. Which one is not a purpose of canal lining?
A) Reduce seepage
B) Increase velocity
C) Improve water quality
D) Prevent erosion
✅ Answer: C
Q41. A non-perennial canal is suitable for:
A) All seasons
B) Kharif season
C) Rabi season
D) Perennial crops
✅ Answer: B
Q42. Which loss is minimum in lined canal?
A) Evaporation
B) Seepage
C) Transpiration
D) Absorption
✅ Answer: B
Q43. Which canal type requires minimum excavation?
A) Ridge
B) Contour
C) Power
D) Feeder
✅ Answer: B
Q44. Lining increases life of canal by reducing:
A) Velocity
B) Erosion
C) Discharge
D) Head loss
✅ Answer: B
Q45. Seepage loss causes:
A) Soil fertility
B) Water table rise
C) Rainfall
D) Less discharge
✅ Answer: B
Q46. Which is a lining material?
A) Wood
B) Steel
C) Concrete
D) Rubber
✅ Answer: C
Q47. Main objective of canal irrigation is to:
A) Drain water
B) Generate power
C) Supply water to crops
D) Increase rainfall
✅ Answer: C
Q48. Which canal is best for uniform distribution?
A) Contour
B) Ridge
C) Feeder
D) Power
✅ Answer: B
Q49. Which loss is ignored in design usually?
A) Seepage
B) Absorption
C) Evaporation
D) Transpiration
✅ Answer: D
Q50. Canal lining is recommended when:
A) Water is cheap
B) Losses are negligible
C) Seepage is high
D) Canal is temporary
✅ Answer: C