Portable sprinkler Irrigation system design procedure

Abstract EN

A correctly designed lateral in a portable sprinkler irrigation system has to be designed to uniformly apply water to the soil at a rate less than the infiltration rate of the soil to prevent runoff, and to meet the crop water requirements in the first place.

For sprinkler-irrigation to be profitable, system designs must be based on precise calculations and rigorous management.

The precision with which sprinkler -irrigation lateral and network’s are designed is of fundamental importance to system operation, the uniformity of distribution of water and fertilizer, and the consumption of energy.

There are several factors involved in the design of sprinkler laterals.

These factors are interrelated and the design requires non-linear equations.

This paper will discuss the issue from a conceptual standpoint using both research and on-farm examples.

The objective is attaining greater acceptance of this design criteria so that irrigator’s can avoid the reduced crop production and runoff that occur when distribution uniformity is violated.

As such, this paper presents the mathematical background of a computerized interactive computation design procedure.

The computation model presented in this paper is based on equations of mass and energy conservation within an elemental control volume on the lateral.

The lateral and mainline are solved by using Darcy-Weisbach equation within segmental magnitude of Reynolds number (Re).

Pipe diameter is chosen according to the critical velocity and discharge relationship without assumptions or trial and error procedure.

The design is appropriate to be used with limited or unlimited water sources to determine the suitable area .The computer program is able to specify the most suitable sprinkler specification to match soil infiltration rate.

The program of computation has been developed for this and applied to a lateral for the first time.

Results from this simple model are precise and are similar to those from other validated models.

Precision design increase efficiency of water and fertilizer distribution.

This method can be applied to the design of pressurized-irrigation lateral’s or networks.

The interactive mode and fast response make the design procedure a practical aid which can be easily used even for an unskilled person.