OPTIMAL DESIGN OF LIFT IRRIGATION SCHEMES

Abstract

Presently, irrigation is the largest consumer of water. Due to topographic constraints water cannot be always transported gravitationally to crop fields. Lifting of water for irrigation is unavoidable in many cases. The shape and size of field area to be irrigated, its elevation and its distance from water source with respect to field affects the cost of irrigation. Water lifting for the areas on high level lands can be done in the single stage or in the multiple stages of lifting. In this study an attempt has been made to know the economical rising main diameter, relative economics involved in single and multiple stages of lifting water with respect to static head,discharge and length of rising main pipe.Economic analysis has been carried out to determine the cost of pumped water for various values of discharges, length and diameter of rising main pipe and number of pumping stages. The analysis results have been used to select the optimal design.The task of study of relative economics for the schemes necessitated the development of a computer program. In the economic analysis present market rates of various items have been used. Based upon the economics few nomographs have been developed and some guide lines have been framed which are useful in the design of Lift Irrigation,Schemes...