A Free Computational Application to Design and Sizing Subunits with any Geometry in Drip Irrigation Systems

Abstract

The full design of drip irrigation systems is very complex, because of the large numbers of parameters to be considered. In particular, the proposed methods to design the different pipes of subunit systems are only useful in the cases of rectangular, triangle or trapezoidal geometry. The subunits could have any geometrical shape when its geometry is adapted to the borders of parcels. In this case, the use of a computational tool is actually essential. As irrigation technicians are not to pay high prices for computational design tools, the authors decided to develop a free design software. First of all, a calculus sheet (Excel programming with Visual Basic for Application -VBA-) was used. The users then had to define the shape of the subunit introducing the length of every lateral that made up the subunit and the other hydraulic features. The user could easily size the pipes fixing the maximum allowed pressure head losses in subunit. This application was called KS and it has been used by many technicians for the design of drip irrigation systems over the last few years. Last version, calles KS2004, introduces new and powerful features as the possibility of draw the shape of subunits by AutoCad software, importing the file and sizing the subunit by the developed application using Excel Calculus sheet and VBA. The new tool has a full data base of pipes and emitters, and singular head losses produced by the insertions of emitters in laterals have been considered as well. The tool seeks all the possible combinations of diameter of lateral and manifold, ordered by some economic criteria. Once a subunit has been sized, a file can be exported to be read from AutoCad and reporting directly the results over the original draw.The application can be unloaded from the web site of this research group within the website of the Polytechnic University of Valencia. A distribution list has been created and every improvement is sent by e-mail to all KS’s users.