Understanding the distribution characteristics of an individual
irrigation sprinkler or spray nozzle is necessary to improve the uniformity
of any sprinkler system. Relevant factors affecting the improvement
of the irrigation performance of sprinkler systems are the engineering
factors (i.e. operating pressure, riser height of sprinkler / nozzle, sprinkler
type, deflector plates, and nozzle diameter), and the climatic factors (i.e.
wind speed, air humidity and air temperature). It is important to highlight
that this study has been focused on center pivot sprinkler irrigation
system as it is the widely used sprinkler irrigation system in new lands of
Egypt ( Toshka, Sinai and Nobaria). Therefore, five different types of
spray nozzles, used on center pivot irrigation system, have been tested
and evaluated. Several outdoor single-sprinklers and overlapped -
sprinklers irrigation tests have been conducted for determining: water
application rate, uniformity of water distribution, and application
efficiency, under different engineering and climatic conditions.
Various sprinkler types - pressure -riser height combinations were
used and the variation of application rate and weather conditions (i.e. air
temperature, relative humidity, and wind speed) were measured during
the test. A statistical approach has been used with these data to estimate
water distribution uniformity coefficient CU, and water application
efficiency AE, using a linear model. CU, and AE as sprinkler irrigation
performance parameters, were estimated as functions of the sprinkler
type, nozzle characteristics, riser height, operating pressure, and wind
speed. Other climatic and engineering factors were not of significant
effect on the CU or AE in this study. The model can be a useful tool to
select the operational conditions (e.g. working pressure, riser height,
nozzle type) |
