Necessity of Irrigation in Civil Engineering

Necessity of Irrigation in Civil Engineering

1. Necessity of Irrigation 1.Inadequate rainfall- 2.Water holding capacity of soil- 3.Uneven distribution of rainfall 4.Increasing the crop yield. 5.Growing a no of crops 6.Growing perennial crops 7.growing superior crops 8.Inssurance against draught.

2. Types of Irrigation systems Natural Irrigation system 1. Rainfall 2. Inundation system/Flood irrigation system Artificial Irrigation a) Gravity/Traditional irrigation methods Surface Flow Irrigation Furrow irrigation Basin irrigation Border irrigation b) Pressurised irrigation methods Drip irrigation Sprinkler irrigation Lift irrigation a)Open well irrigation b)Tube well irrigation

3. ARTIFICIAL IRRIGATION SYSTEM Gravity/Traditional irrigational methods Pressurised irrigation method Surface flow irrigation Furrow irrigation Basin Irrigation Border Irrigation Lift irrigation Sprinkler Irrigation Drip Irrigation

4. Inundation irrigation Done by a canal taking off from a river in flood without any diversion work. It depends on the periodical rise in water level of the river and the supply is drawn through open cuts in the river bank.

5. Inundation Irrigation/Flood Irrigation/Non-perenial irrigation method

6. Surface Flow Irrigation

7. Surface irrigation Application of water by gravity flow to the surface of the field. Either the entire field is flooded (basin irrigation) or the water is fed into small channels (furrows) or strips of land (borders).

8. Basic components The basic components are: Water source Supply Lines Control mechanism Dams or dikes of control Furrows of irrigation Drainage system Re-use of irrigation water

9. Furrow Irrigation

10. Advantages of Furrow Irrigation Cost-efficient method Lower unit cost of pumped water. Reduces chemical leaching. Higher crop yields ensured Initial cost low Mass area irrigation possible. Time and Labour saving method. Recirculating irrigation runoff water is possible.

11. Disadvantages of Furrow irrigation Not Suitable for sandy soil & for some crops. Initial field preparation & labor cost is high. Movement of equipment is difficult in the furrow fields. Salts are accumulated in ridges of soil between the furrows. 

12. Basin Irrigation

13. Basin Irrigation Suitable for many field crops. Area is divided into number checks or basins. Basin irrigation design is simpler than either furrow or border design since tail water is prevented fromthe existing field and the slopes are usually very small or zero.

14. Border Irrigation Type of surface irrigation where the field is divided into strips separated by border ridges running down the gradient of the field. In contrast to basin irrigation bunds are not to contain the water for ponding but to guide it as it flows down the field.

15. Border Irrigation

16. Advantages of Border irrigation Improved ability to irrigate small crops Economical method of irrigation ensures uniform application of water Good control on irrigation water and high H 2 O application efficiency Initial cost is high,but it requires less labour and has low maintenance cost Wastage of H 2 O and soil erosion is reduced as there is bund around the basin, Suitable for most soils.

17. Disadvantages of Border irrigation Too many ridges which occupy the larger area of land. Layout requirement in land preparation and irrigation is much bigger in check basin as compared to other methods Suitable for only crops like wheat, barley, groundnut & fodder Requires land grading & shaping of land

18. Drip/Micro/ Trickle Irrigation method Most water efficient method of irrigation. Water drops right near the root zone of a plant in a dripping motion. Improved form of surface irrigation. Supplies water using a network of pipes. Emitter/dripper supplies water at a rate of 2-10 litres per hour. Water applied laterally/vertically due to capillary action. Properly installed system can reduce the losses of through evaporation and runoff. Area covered by one emitter depends on flow rate,soil type,soil moisture, horizoltal & vertical permeabilities of soil.

19. Components Pipe networks Emitters/drippers Filtration unit Fertigation unit pumping unit Control unit/control head

20. Advantages of Drip Irrigation System Efficiency more than 90% Evaporation losses low Deep percolation losses eliminated therefore the soil nutrients are preserved. Maintains constant moisture in the root zone Crop yield is high. Suitable for small trees & spaced plants No fungus Weeds & soil crusting eliminated Useful for arid regions No soil erosion, no water logging, no field leveling required, no salinity problems, no wastage of land for preparation of borders, checks, field channels & can be used on any topography. Zero labour

21. Disadvantages of Drip Irrigation System Difficult Installation process Maintenance problems Not suitable for closely planted crops During high winds plants may topple In case water is highly saline, dissolved salts are left in root zones when rain flushes these salts into active zones the crops gets affected. Expensive irrigation system

22. Er . Shabina Masoodi Head of the Department Department of Civil Engineering SSM College Of Engineering