1. HYDRAULICS_6 Design of Irrigation Systems by László Ormos

2. WATER HEAD Water energizing: 1.By gravity The water flows from tanks over the irrigated field. 2.By pressurization The water flows under pressure by pump into the water network. Water sources: 1.Open water bodies 2.Underground water bodies 3.Reclaimed sewage water

3. WATER HEAD Tasks for water head: 1.Filtration Impurities in water must be filtered (sand, silt, clay, planktons, algae, etc.) 2.Pressure control Adequate pressure has to be set for the required outlet quantity. 3.Flow control The outlet flow quantity must be controlled. 4.Control of fertilization The required quantity of fertilizers and feeding into the water must be supervised and controlled. 5.Timing The irrigation intervals and outlet quantity of water must be controlled.

4. WATER HEAD 1.Filtration In order to avoid clogging of water emitters, the water has to be filtered before approaching the emitter. Impurities in water can be classified by the followings: organic debris, inorganic solid particles (sand, silt, clay, insoluble materials), organic living creatures (zooplankton, phytoplankton, algae, bacteria, fungi, etc.) Surface water from open water bodies contains more impurities than underground water.

5. WATER HEAD Screen filters External rough filter Internal fine filter Drainage valve

6. WATER HEAD Disk filters

7. WATER HEAD Media filters Filter media

8. WATER HEAD 2.Pressure control Pressure regulator:setting of required pressure in the irrigation network. Pressure limiter: setting of maximum pressure permitted for the pump. One-way valve: prevents the flow of water back from the irrigation network into the water network/spring. Water meter:measures (and controls) the quantity of outlet water.

9. WATER HEAD 3.Flow control Semi-automatic control: it is combined with the water meter, irrigation time is setting and start by hand. Full-automatic control: interval and irrigation time is switched by a preset electronic watch. Computer control: interval and irrigation time, shift, and back-flushing is controlled by an irrigation computer. Intelligent control: computer control influenced by the environmental circumstances, continuously.

10. WATER HEAD 4.Control of fertilization pH-control:equipment for setting the concentration of fertilizer by measuring the pH-value. EC control:equipment for continuous measuring the conductivity of outlet/drain liquid. Fertilizer injector control: for mixing fertilizers with the outlet water by flushing tank, Venturi- injector or electric driven chemical pump.

11. WATER HEAD 5.Timing Mechanical clock: must be set and start by hand. Electronic switch: irrigation time and interval is set by hand, start of irrigation is automatic. Irrigation computer: all the settings are programmed by on-board switches, or by PC with remote control, and start is automatic.

12. WATER HEAD Hand-operated water head with fertilization Main valve One-way valve Inlet water Outlet to Plot 2 Q Pressure regulator Water meter with timer Outlet to Plot 1 Valves to Plots Filter Venturi-injector Fertilizer tank Fertilizer valves

13. WATER HEAD Irrigation computer-controlled water head Inlet water Main magnet ventil One-way valve Outlet to Plot 2 Pressure regulator Water meter with data output Outlet to Plot 1 Magnet ventils to Plots Q Filter Filter with back- flush control Waste water magnet ventil Magnet ventils for back-flush control Irrigation computer

14. References Azenkot, A.(1998):”Design Irrigation System”. Ministry of Agricul- ture Extension Service (Irrigation Field service), MASHAV Israel Dr. Avidan, A.(1995):”Soil-Water-Plant Relationship”. Ministry of Agriculture Extension Service (Irrigation Field service), CINADCO, Ministry of Foreign Affairs, MASHAV, Israel Sapir, E.-Dr. E. Yagev (1995):”Drip Irrigation”. Ministry of Agricul- ture and Rural Development, CINADCO, Ministry of Foreign Affairs, MASHAV, Israel Sapir, E.-Dr. E. Yagev (2001):”Sprinkler Irrigation”. Ministry of - culture and Rural Development, CINADCO,Ministry of Foreign Affairs, MASHAV, Israel Eng. Nathan, R. (2002):”Fertilization Combined with Irrigation (Fertigation)”. Ministry of Agriculture and Rural Development, CINADCO,Ministry of Foreign Affairs, MASHAV, Israel