Design of blocked-end borders

The computations needed to evaluate and design blocked-end borders where the flow is cut off before or shortly after the advance phase is complete are substantially more detailed than the procedures outlined above for furrow and open-end border irrigation systems. In fact, the volume balance methods given previously are relatively weak for this particular case of surface irrigation. Generally, the computations for blocked-end borders are best performed with zero-inertia or full hydrodynamic simulation models which are beyond the scope of this paper.

A number of studies have been made to develop relationships among the most important variables involving border irrigation using a dimensionless approach and the higher level simulation models. The interested reader might want to refer to Strelkoff and Katapodes, Strelkoff and Shatanawi, Shatanawi and Strelkoff, and Yitayew and Fangmeier for some of these reports.

The design procedure outlined below is an extension of the approaches already given and consistent with the level of treatment given herein. The procedure given here is intended to be conservative and will yield designs capable of performing at somewhat lower application efficiencies than is perhaps possible using the more comprehensive methods.