1. Concept Explanation (Exam-Focused)
Irrigation efficiency indicates how effectively the supplied water is being used by crops.
In simple words:
It is the ratio of useful water to total water supplied.
Because of losses like seepage, evaporation, runoff etc., 100% efficiency is never achieved in real practice.
Types of Irrigation Efficiencies (Most Important)
1. Conveyance Efficiency (ηc)
It measures the efficiency of water transport from source to field.
ηc=Water at fieldWater at source×100\eta_c = \frac{Water\ at\ field}{Water\ at\ source} \times 100ηc=Water at sourceWater at field×100
Losses considered:
• Seepage
• Evaporation
• Leakage
Typical value:
• Unlined canal: 60–70%
• Lined canal: 80–90%
2. Application Efficiency (ηa)
It measures how much water delivered to field is stored in root zone.
ηa=Water stored in root zoneWater delivered to field×100\eta_a = \frac{Water\ stored\ in\ root\ zone}{Water\ delivered\ to\ field} \times 100ηa=Water delivered to fieldWater stored in root zone×100
Losses considered:
• Runoff
• Deep percolation
• Evaporation
3. Storage Efficiency (ηs)
It indicates how much of required water is actually stored in root zone.
ηs=Water storedWater required×100\eta_s = \frac{Water\ stored}{Water\ required} \times 100ηs=Water requiredWater stored×100
4. Overall Irrigation Efficiency (ηo)
It is the product of conveyance and application efficiency.
ηo=ηc×ηa\eta_o = \eta_c \times \eta_aηo=ηc×ηa
🔥 Most repeated formula in exams
2. Important Formulas (With Units)
Where:
Ws = water at source (m³)
Wf = water at field (m³)
Wr = water stored (m³)
Wreq = water required (m³)
3. Short Notes / One-Liners
• Maximum efficiency possible is drip irrigation.
• Surface irrigation has lowest efficiency.
• Lined canals increase conveyance efficiency.
• Deep percolation reduces application efficiency.
• ηo is always less than ηc and ηa.
• High efficiency = less water wastage.
• Overall efficiency is never 100%.
4. PYQ Patterns
Frequently Asked:
Direct numericals on ηc and ηa
Find overall efficiency
Compare efficiencies of methods
Conceptual: which loss affects which efficiency?
Typical Traps:
• Multiplying percentages wrongly
• Forgetting to divide by 100
• Confusing water delivered vs water stored
• Assuming efficiencies add (they multiply)
5. Solved Examples
Example 1 (Numerical)
Water at source = 100 m³
Water at field = 80 m³
ηc=80100×100=80%\eta_c = \frac{80}{100} \times 100 = 80\%ηc=10080×100=80%
Example 2 (Numerical)
Water delivered to field = 80 m³
Water stored in root zone = 60 m³
ηa=6080×100=75%\eta_a = \frac{60}{80} \times 100 = 75\%ηa=8060×100=75%
Example 3 (Overall Efficiency)
ηo=0.80×0.75=0.60=60%\eta_o = 0.80 \times 0.75 = 0.60 = 60\%ηo=0.80×0.75=0.60=60%
6. MCQs (50 Exam-Level)
Q1. Conveyance efficiency represents:
A) Water stored / water required
B) Water at field / water at source
C) Water stored / water delivered
D) Water lost / water supplied
✅ Answer: B
Q2. Which loss affects conveyance efficiency most?
A) Runoff
B) Deep percolation
C) Seepage
D) Transpiration
✅ Answer: C
Q3. Application efficiency is reduced due to:
A) Seepage
B) Evaporation
C) Runoff
D) Both B and C
✅ Answer: D
Q4. Which efficiency is highest in drip irrigation?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: D
Q5. Overall irrigation efficiency is:
A) ηc + ηa
B) ηc – ηa
C) ηc × ηa
D) ηc / ηa
✅ Answer: C
Q6. Which is always true?
A) ηo > ηc
B) ηo < ηc
C) ηo = 100%
D) ηo > ηa
✅ Answer: B
Q7. Lining canals improves:
A) Application efficiency
B) Storage efficiency
C) Conveyance efficiency
D) Overall demand
✅ Answer: C
Q8. If ηc = 80% and ηa = 70%, ηo is:
A) 150%
B) 56%
C) 75%
D) 60%
ηo=0.8×0.7=0.56\eta_o = 0.8 \times 0.7 = 0.56ηo=0.8×0.7=0.56
✅ Answer: B
Q9. Which irrigation method has lowest efficiency?
A) Drip
B) Sprinkler
C) Surface
D) Micro irrigation
✅ Answer: C
Q10. Which efficiency depends on field condition?
A) Conveyance
B) Application
C) Storage
D) None
✅ Answer: B
Q11. Deep percolation loss affects:
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: B
Q12. Which efficiency indicates water use at plant root?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: C
Q13. Which is a numerical trap?
A) Forgetting % to decimal
B) Adding efficiencies
C) Wrong units
D) All of the above
✅ Answer: D
Q14. If no loss occurs in field, application efficiency is:
A) 0%
B) 50%
C) 100%
D) Infinite
✅ Answer: C
Q15. Which efficiency is concerned with canal system?
A) Application
B) Storage
C) Conveyance
D) Overall
✅ Answer: C
Q16. Water stored = 40 m³, water required = 50 m³. ηs = ?
ηs=4050×100=80%\eta_s = \frac{40}{50} \times 100 = 80\%ηs=5040×100=80%
A) 60%
B) 70%
C) 80%
D) 90%
✅ Answer: C
Q17. Which efficiency can exceed 100%?
A) Conveyance
B) Application
C) Storage
D) None
✅ Answer: D
Q18. Maximum possible overall efficiency is:
A) 50%
B) 70%
C) 90%
D) Less than 100%
✅ Answer: D
Q19. Which is true?
A) ηo > ηc
B) ηo < ηa
C) ηo = ηc
D) ηa = 100 always
✅ Answer: B
Q20. Which method gives maximum water saving?
A) Flood
B) Basin
C) Sprinkler
D) Drip
✅ Answer: D
Q21. If water at source is 200 m³ and water at field is 150 m³, conveyance efficiency is:
ηc=150200×100=75%\eta_c = \frac{150}{200} \times 100 = 75\%ηc=200150×100=75%
A) 60%
B) 70%
C) 75%
D) 80%
✅ Answer: C
Q22. Which loss does not affect conveyance efficiency?
A) Seepage
B) Evaporation
C) Runoff
D) Leakage
✅ Answer: C
📝 Explanation: Runoff occurs in field, not in canal.
Q23. Application efficiency mainly depends on:
A) Canal lining
B) Soil condition
C) Reservoir
D) Rainfall
✅ Answer: B
Q24. Which efficiency is related to crop root zone?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: C
Q25. If ηc = 90% and ηa = 80%, ηo is:
ηo=0.9×0.8=0.72=72%\eta_o = 0.9 \times 0.8 = 0.72 = 72\%ηo=0.9×0.8=0.72=72%
A) 70%
B) 72%
C) 75%
D) 80%
✅ Answer: B
Q26. Which irrigation system gives maximum application efficiency?
A) Flood
B) Basin
C) Sprinkler
D) Drip
✅ Answer: D
Q27. Storage efficiency becomes zero when:
A) No water required
B) No water stored
C) No rainfall
D) No seepage
✅ Answer: B
Q28. Which efficiency is improved by land leveling?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: B
Q29. Which is a wrong statement?
A) ηo < ηc
B) ηo < ηa
C) ηo = ηc + ηa
D) ηo = ηc × ηa
✅ Answer: C
Q30. If deep percolation loss is high, which efficiency reduces most?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: B
Q31. Which irrigation efficiency is affected by canal seepage?
A) Storage
B) Application
C) Conveyance
D) Overall
✅ Answer: C
Q32. If no loss occurs in conveyance system, ηc is:
A) 0%
B) 50%
C) 90%
D) 100%
✅ Answer: D
Q33. Which efficiency shows how well irrigation meets crop demand?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: C
Q34. Water delivered = 100 m³, water stored = 50 m³. ηa = ?
ηa=50100×100=50%\eta_a = \frac{50}{100} \times 100 = 50\%ηa=10050×100=50%
A) 40%
B) 50%
C) 60%
D) 70%
✅ Answer: B
Q35. Which irrigation method has lowest conveyance efficiency?
A) Drip
B) Sprinkler
C) Surface
D) Micro irrigation
✅ Answer: C
Q36. Which efficiency is directly affected by runoff?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: B
Q37. If ηc = 70% and ηo = 56%, ηa is:
ηa=0.560.70=0.8=80%\eta_a = \frac{0.56}{0.70} = 0.8 = 80\%ηa=0.700.56=0.8=80%
A) 70%
B) 75%
C) 80%
D) 85%
✅ Answer: C
Q38. Which factor does not affect irrigation efficiency?
A) Soil type
B) Climate
C) Crop type
D) Canal length only
✅ Answer: D
Q39. Which is a correct statement?
A) Overall efficiency can be more than 100%
B) Conveyance efficiency can be zero
C) Application efficiency can be 100%
D) Storage efficiency is always 100%
✅ Answer: C
Q40. The main aim of improving irrigation efficiency is to:
A) Increase rainfall
B) Reduce water wastage
C) Increase seepage
D) Increase evaporation
✅ Answer: B
Q41. Which efficiency is used in designing canal capacity?
A) Application
B) Storage
C) Conveyance
D) Overall
✅ Answer: C
Q42. Which efficiency reflects farmer’s field management?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: B
Q43. Which irrigation method has overall efficiency about 90%?
A) Flood
B) Basin
C) Sprinkler
D) Drip
✅ Answer: D
Q44. Which loss is not considered in application efficiency?
A) Runoff
B) Deep percolation
C) Evaporation
D) Seepage in canal
✅ Answer: D
Q45. Which efficiency is improved by canal lining?
A) Storage
B) Application
C) Conveyance
D) Overall demand
✅ Answer: C
Q46. Which is a typical numerical trap?
A) Using % directly in multiplication
B) Converting % to decimal
C) Using wrong formula
D) All of the above
✅ Answer: D
Q47. If storage efficiency is 100%, it means:
A) No rainfall
B) No loss in field
C) All required water stored
D) No seepage in canal
✅ Answer: C
Q48. Which one is false?
A) ηo < ηc
B) ηo < ηa
C) ηo = ηc × ηa
D) ηo > ηc
✅ Answer: D
Q49. Which efficiency is most affected by farmer’s skill?
A) Conveyance
B) Application
C) Storage
D) Overall
✅ Answer: B
Q50. Irrigation efficiency is improved mainly by:
A) Over irrigation
B) Proper drainage
C) Better irrigation methods
D) Increasing rainfall
✅ Answer: C
Final SSC JE Master Table (Memorize)
Golden Formula (Most Repeated):
ηo=ηc×ηa\boxed{\eta_o = \eta_c \times \eta_a}ηo=ηc×ηa