NATIONAL INSTITUTE OF TECHNOLOGY , PATNA DEPARTMENT OF CIVIL ENGINEERING WATER RESOURCE ENGINEERING Course: IRRIGATION & WATER MANAGEMENT By SANJAN BANERJEE M.TECH SEMESTAR-1ST Roll- 1625004 MODERN METHODS of IRRIGATION
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NATIONAL INSTITUTE OF TECHNOLOGY , PATNA
DEPARTMENT OF CIVIL ENGINEERING WATER RESOURCE ENGINEERING
Course: IRRIGATION & WATER MANAGEMENT
By
SANJAN BANERJEEM.TECH
SEMESTAR-1STRoll- 1625004
MODERN METHODS of IRRIGATION
WHAT IS IRRIGATION? It is defined as the science of artificial
application of water to the land , in accordance with ‘crop requirements’ throughout the ‘crop period’ for full fledge nourishment of the crops.
Types of IRRIGATION
IRRIGATION
SURFACE
FLOW
FLOOD
PERENNIAL
LIFT
SUBSURFACE
NATURAL
ARTIFICIAL
IRRIGATION IN THE PAST Farming was more focused on subsistence rather than
selling products in the market. Labor intensive. Irrigated land used to be small. Highly dependent on weather & Inefficient.
More focus is now on selling the output. Machine intensive & more sophisticated. Rains are no longer the controlling force.
MODERN CONSIDERATIONS
Objective for Modern Methods:
Artificial control over supply of water.
Low losses & High Efficiency.
Less labour requirement & degree of freedom over
MANPOWER MANAGEMENT.
Water Application Efficiency as well as Distribution
Efficiency is very high.
Simontaneous injection of Fertilizer & Pesticides.
Modern Methods of Irrigation
SPRINKLER IRRIGATION
DRIP IRRIGATION
SPRINKLER IRRIGATION
Consists of a network of pipes and sprinklers spaced at suitable
places.
At the nozzle Pressure head is converted to Velocity head.
Area of Land wetted depends on following factors i.e. judges
‘Efficiency’ 1. Velocity of water Jet
2. Angle of Flow
3. Type of Sprinkler & it’s design
4. Wind Speed & Direction.
Just like artificial application of Rain.
Sprinkler Continues….
ADAPTABILITY Irregular Topography i.e. unsuitable for Surface Irrigation. Gradient is Steeper. Highly Sandy soil or Highly Clayey Soil. High water table i.e. near to ground. Seasonal Water demand is low for that area. Crops having following Factors
1. Required Humidity Control (Tobacco).2. Having shallow roots.3. Required high & frequent irrigation.
LAYOUT OF SPRINKLER IRRIGATION SYSTEM
COMPONENTS OF A SPRINKLER IRRIGATION SYSTEM
COMPONENTS continues…
1. Pumping Set 2. Main Line
3. Lateral Line 4. Sprinkler Heads
5. Debris Screenes 6. Desilting Basins
7. Booster Pump 8. Take-off Valves
9. Flow Control Valve
TYPES OF SPRINKLER IRRIGATION SYSTEM
1. Rotating Head System
A. Portable system
B. Semi-portable system
C. Solid Set system
D. Semi Permanent System
E. Permanent System
2. Perforated Type System
3. Centre Pivot System
CENTRE PIVOT SYSTEM
SPRAY PATTERN
SPRAY PATTERN continues…
VARIATION IN PRESSURE
DRIP IRRIGATION
Also known as TRICKLE Irrigation
Water is applied frequently but at a slow rate (<14lit/hr)
Dia. of pipe & Emitters are small compared to Sprinkler Irrigation
No need for separate drainage System.
Full control over Weeds.
Ferti-gation possible.
Some Salient Points….
Acceptable to any Farmable slope.
Crop & Drippers are placed on contour lines to minimize
discharge.
In Clayey soil, water application rate should be low.
In Sandy Soil, Water Application Rate should be moderate.
If water is not clean, then system may chocked. Deposition of
Fertilizer (Ca & Na precipitate) would also cause chocking.
Suitable sand filters needed to counter chocking.
DRIP IRRIGATION SYSTEM LAYOUT
COMPONENTS OF A DRIP IRRIGATION SYSTEM
1. Drippers 2. Valves 3. Filters 4. Main line 5. Sub-Main line 5. Lateral Line 6. Pump 7. Fertilizer tank (if any)
Valves Used:
1. Flow Control Valve 2. Non Return Valve3. Pressure Regulating Valve 4. Pressure Relief Valve5. Air & Vaccum Release Valve
Drippers & Types
Operating Pressure: 1. Low Pressure Dripper (Pr
<0.8m)
2. Medium Pressure (2<Pr<8m)
3. High Pressure (8<Pr<15)
Path Cross Section: 1. Low (<0.8mm)
2. Medium (0.8 to 1.5mm)
3. Wide (above 1.5mm)
TYPES of DRIPPERS continues…
Discharge Rates: 1. Low ( Q < 4lit/hr)
2. Medium (4 <Q <10Lit/hr)
3. High (Q < 15lit/hr)
Different types of Emitter: 1. Compensating
2. Continouas Flushing 3. Flushing
4. Long Path 5. Multi-outlet
6. Orifice 7. Vortex
MAINTAINANCE OF DRIP IGRRIGATION SYSTEM
Flushing of Sub-mains & Laterals: Frequently done for Low
Discharge & rarely done for High Discharge System to removed entrapped Silt or
Sand in pipe.
Chemical Treatment: Applied when clogging was due to precipitation
of dissolved salt like Carbonate, Bi-carbonate of Ca, Fe, Na & Sulphur Slimes of
Bacteria.
Acid Treatment: HCl is applied till pH-4 is observed and system is
closed for 24hrs.
Chlorine Treatment: Has to be done in the form of Bleaching Powder
to avoid growth of Bacteria.
REFERENCES
Bibliography:
Michel A.M. (2011, 2nd edition), Irrigation Theory and Practice, Vikas Publishing House Pvt. Ltd. , New Delhi. Garg S.K. (28th edition), Irrigation Engineering and Hydraulic Structures, Khanna Publishers, New Delhi.
THANK YOU
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