ANALYSIS OF EFFECT OF SPRINKLER FUNCTION PRESSURE ON UNIFORMITY OF WATER DISTRIBUTION IN TRICKLE IRRIGATION: CASE STUDY IN TORBAT HEIDARIYEH ZONE

Using of trickle irrigation systems (sprinklers) is one of the efficient solutions in saving and further protection from water supplies. If these systems are properly designed, executed, and managed, they will cause reducing water wastage and improving uniformity of water distribution. Uniformity of water distribution will be possible in trickle irrigation (sprinkler) when the factors, which cause reduction of uniformity, are identified and controlled as possible. In order to analyze effect of pressure of sprinkler function on uniformity of water distribution, several experiments were carried out according to ISO 7749/2 Standard (1990) by single sprinkler technique in a pilot field locating on Torbat Heidariyeh Zone during spring and summer in 2016. The test was implemented at 3 different pressure levels (2.2, 3.5, and 4.7 atmospheres) within the range of suggested pressures by Manufacturing Company. Analysis on results of finding from uniformity of water distribution at different pressure levels signifies that there is significant difference between the studied pressures at level of 5%. The mutual effect of sprinkler type and pressure suggests that following to rise of pressure at any sprinkler, uniformity of water distribution has been increased and water distribution uniformity coefficient has been added by rising pressure (from 2.2 to 4.7 atmospheres) and this relationship was not linear but this gradient was higher at low pressures (2.2-3.5 atmospheres) than high pressures (3.5- 4.7 atmospheres). If pressure level (about 3.5- 4.7 atmospheres) has been selected in the studied sprinkler, uniformity coefficient will be greater than 80%.